MT40A512M8HX-083E:A

4Gb: x4, x8, x16 DDR4 SDRAM Features DDR4 SDRAM MT40A1G4 MT40A512M8 MT40A256M16 • • • • Databus write cyclic redundancy check (CRC) Per-DRAM addressability Connectivity test (x16) Post package repair (PPR) and soft post package repair (sPPR) modes • JEDEC JESD-79-4 compliant Features • • • • • • • • • • • • • • • • • • • • • • • VDD = V DDQ = 1.2V ±60mV VPP = 2.5V, –125mV/+250mV On-die, internal, adjustable V REFDQ generation 1.2V pseudo open-drain I/O TC of 0°C to 95°C – 64ms, 8192-cycle refresh at 0°C to 85°C – 32ms at 85°C to 95°C 16 internal banks (x4, x8): 4 groups of 4 banks each 8 internal banks (x16): 2 groups of 4 banks each 8n-bit prefetch architecture Programmable data strobe preambles Data strobe preamble training Command/Address latency (CAL) Multipurpose register READ and WRITE capability Write and read leveling Self refresh mode Low-power auto self refresh (LPASR) Temperature controlled refresh (TCR) Fine granularity refresh Self refresh abort Maximum power saving Output driver calibration Nominal, park, and dynamic on-die termination (ODT) Data bus inversion (DBI) for data bus Command/Address (CA) parity Options1 • Configuration – 1 Gig x 4 – 512 Meg x 8 – 256 Meg x 16 • FBGA package (Pb-free) – x4, x8 – 78-ball (9mm x 11.5mm) – Rev. A – 78-ball (9mm x 10.5mm) – Rev. B • FBGA package (Pb-free) – x16 – 96-ball (9mm x 14mm) – Rev. A – 96-ball (9mm x 14mm) – Rev. B • Timing – cycle time – 0.625ns @ CL = 22 (DDR4-3200) – 0.682ns @ CL = 20 (DDR4-2933) – 0.682ns @ CL = 21 (DDR4-2933) – 0.750ns @ CL = 18 (DDR4-2666) – 0.750ns @ CL = 19 (DDR4-2666) – 0.833ns @ CL = 16 (DDR4-2400) – 0.833ns @ CL = 17 (DDR4-2400) – 0.937ns @ CL = 15 (DDR4-2133) – 0.937ns @ CL = 16 (DDR4-2133) – 1.071ns @ CL = 13 (DDR4-1866) • Operating temperature – Commercial (0° ≤ T C ≤ 95°C) – Industrial (–40° ≤ T C ≤ 95°C) – Revision Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1 Marking 1G4 512M8 256M162 HX RH HA GE -062E -068E -068 -75E -75 -083E -083 -093E -093 -107E None IT :A :B 1. Not all options listed can be combined to define an offered product. Use the part catalog search on http://www.micron.com for available offerings. 2. Not available on Rev. A. 3. Restricted and limited availability. Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. Products and specifications discussed herein are subject to change by Micron without notice. 4Gb: x4, x8, x16 DDR4 SDRAM Features Table 1: Key Timing Parameters Speed Grade Data Rate (MT/s) Target tRCD-tRP-CL -062E6 3200 22-22-22 13.75 13.75 13.75 -068E5 2933 20-20-20 13.64 13.64 13.64 -0685 2933 21-21-21 14.32 14.32 14.32 -075E4 2666 18-18-18 13.5 13.5 13.5 -0754 2666 19-19-19 14.25 14.25 14.25 -083E3 2400 16-16-16 13.32 13.32 13.32 -0833 2400 17-17-17 14.16 14.16 14.16 -093E2 2133 15-15-15 14.06 14.06 14.06 -0932 2133 16-16-16 15 15 15 -107E1 1866 13-13-13 13.92 13.92 13.92 Notes: tRCD (ns) tRP (ns) CL (ns) 1. 2. 3. 4. 5. Backward compatible to 1600, CL = 11. Backward compatible to 1600, CL = 11 and 1866, CL = 13. Backward compatible to 1600, CL = 11; 1866, CL = 13; and 2133, CL = 15. Backward compatible to 1600, CL = 11; 1866, CL = 13; 2133, CL = 15; and 2400, CL = 17. Backward compatible to 1600, CL = 11; 1866, CL = 13; 2133, CL = 15; 2400, CL = 17; and 2666, CL = 19. Speed offering may have restricted availability. 6. Backward compatible to 1600, CL = 11; 1866, CL = 13; 2133, CL = 15; 2400, CL = 17; 2666, CL = 19; and 2933, CL = 20 and CL = 21. Speed offering may have restricted availability. Table 2: Addressing Parameter 1024 Meg x 4 512 Meg x 8 256 Meg x 16 4 4 2 BG[1:0] BG[1:0] BG0 4 4 4 BA[1:0] BA[1:0] BA[1:0] 64K (A[15:0]) 32K (A[14:0]) 32K (A[14:0]) Column addressing 1K (A[9:0]) 1K (A[9:0]) 1K (A[9:0]) Page size1 512B / 1KB2 1KB 2KB Number of bank groups Bank group address Bank count per group Bank address in bank group Row addressing Notes: 1. Page size is per bank, calculated as follows: Page size = 2COLBITS × ORG/8, where COLBIT = the number of column address bits and ORG = the number of DQ bits. 2. Die revision dependant. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 2 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features Contents General Notes and Description ....................................................................................................................... Description ................................................................................................................................................ Industrial Temperature ............................................................................................................................... General Notes ............................................................................................................................................ Definitions of the Device-Pin Signal Level ................................................................................................... Definitions of the Bus Signal Level ............................................................................................................... Ball Assignments ............................................................................................................................................ Ball Descriptions ............................................................................................................................................ Package Dimensions ....................................................................................................................................... State Diagram ................................................................................................................................................ Functional Description ................................................................................................................................... RESET and Initialization Procedure ................................................................................................................. Power-Up and Initialization Sequence ......................................................................................................... RESET Initialization with Stable Power Sequence ......................................................................................... Uncontrolled Power-Down Sequence .......................................................................................................... Programming Mode Registers ......................................................................................................................... Mode Register 0 .............................................................................................................................................. Burst Length, Type, and Order ..................................................................................................................... CAS Latency ............................................................................................................................................... Test Mode .................................................................................................................................................. Write Recovery(WR)/READ-to-PRECHARGE ............................................................................................... DLL RESET ................................................................................................................................................. Mode Register 1 .............................................................................................................................................. DLL Enable/DLL Disable ............................................................................................................................ Output Driver Impedance Control ............................................................................................................... ODT RTT(NOM) Values .................................................................................................................................. Additive Latency ......................................................................................................................................... Write Leveling ............................................................................................................................................ Output Disable ........................................................................................................................................... Termination Data Strobe ............................................................................................................................. Mode Register 2 .............................................................................................................................................. CAS WRITE Latency .................................................................................................................................... Low-Power Auto Self Refresh ....................................................................................................................... Dynamic ODT ............................................................................................................................................ Write Cyclic Redundancy Check Data Bus .................................................................................................... Target Row Refresh Mode ............................................................................................................................ Mode Register 3 .............................................................................................................................................. Multipurpose Register ................................................................................................................................ WRITE Command Latency When CRC/DM is Enabled ................................................................................. Fine Granularity Refresh Mode .................................................................................................................... Temperature Sensor Status ......................................................................................................................... Per-DRAM Addressability ........................................................................................................................... Gear-Down Mode ....................................................................................................................................... Mode Register 4 .............................................................................................................................................. Post Package Repair Mode .......................................................................................................................... Soft Post Package Repair Mode .................................................................................................................... WRITE Preamble ........................................................................................................................................ READ Preamble .......................................................................................................................................... READ Preamble Training ............................................................................................................................ Temperature-Controlled Refresh ................................................................................................................. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 3 17 17 17 17 18 18 19 21 24 28 30 31 31 34 35 35 38 39 40 41 41 41 42 43 44 44 44 44 45 45 46 48 48 48 48 48 49 50 51 51 51 51 51 52 53 53 54 54 54 54 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features Command Address Latency ........................................................................................................................ 54 Internal V REF Monitor ................................................................................................................................. 54 Maximum Power Savings Mode ................................................................................................................... 54 Mode Register 5 .............................................................................................................................................. 56 Data Bus Inversion ..................................................................................................................................... 57 Data Mask .................................................................................................................................................. 58 CA Parity Persistent Error Mode .................................................................................................................. 58 ODT Input Buffer for Power-Down .............................................................................................................. 58 CA Parity Error Status ................................................................................................................................. 58 CRC Error Status ......................................................................................................................................... 58 CA Parity Latency Mode .............................................................................................................................. 58 Mode Register 6 .............................................................................................................................................. 59 tCCD_L Programming ................................................................................................................................. 60 VREFDQ Calibration Enable .......................................................................................................................... 60 VREFDQ Calibration Range ........................................................................................................................... 60 VREFDQ Calibration Value ............................................................................................................................ 60 Truth Tables ................................................................................................................................................... 61 NOP Command .............................................................................................................................................. 64 DESELECT Command .................................................................................................................................... 64 DLL-Off Mode ................................................................................................................................................ 64 DLL-On/Off Switching Procedures .................................................................................................................. 66 DLL Switch Sequence from DLL-On to DLL-Off ........................................................................................... 66 DLL-Off to DLL-On Procedure .................................................................................................................... 68 Input Clock Frequency Change ....................................................................................................................... 69 Write Leveling ................................................................................................................................................ 70 DRAM Setting for Write Leveling and DRAM TERMINATION Function in that Mode ..................................... 71 Procedure Description ................................................................................................................................ 72 Write-Leveling Mode Exit ............................................................................................................................ 73 Command Address Latency ............................................................................................................................ 75 Low-Power Auto Self Refresh Mode ................................................................................................................. 80 Manual Self Refresh Mode .......................................................................................................................... 80 Multipurpose Register .................................................................................................................................... 82 MPR Reads ................................................................................................................................................. 83 MPR Readout Format ................................................................................................................................. 85 MPR Readout Serial Format ........................................................................................................................ 85 MPR Readout Parallel Format ..................................................................................................................... 86 MPR Readout Staggered Format .................................................................................................................. 87 MPR READ Waveforms ............................................................................................................................... 88 MPR Writes ................................................................................................................................................ 90 MPR WRITE Waveforms .............................................................................................................................. 91 MPR REFRESH Waveforms ......................................................................................................................... 92 Gear-Down Mode ........................................................................................................................................... 95 Maximum Power-Saving Mode ........................................................................................................................ 98 Maximum Power-Saving Mode Entry ........................................................................................................... 98 Maximum Power-Saving Mode Entry in PDA ............................................................................................... 99 CKE Transition During Maximum Power-Saving Mode ................................................................................. 99 Maximum Power-Saving Mode Exit ............................................................................................................. 99 Command/Address Parity .............................................................................................................................. 101 Per-DRAM Addressability .............................................................................................................................. 109 VREFDQ Calibration ........................................................................................................................................ 112 VREFDQ Range and Levels ........................................................................................................................... 113 VREFDQ Step Size ........................................................................................................................................ 113 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 4 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features VREFDQ Increment and Decrement Timing .................................................................................................. 114 VREFDQ Target Settings ............................................................................................................................... 118 Connectivity Test Mode ................................................................................................................................. 120 Pin Mapping ............................................................................................................................................. 120 Minimum Terms Definition for Logic Equations ......................................................................................... 121 Logic Equations for a x4 Device, When Supported ....................................................................................... 121 Logic Equations for a x8 Device, When Supported ....................................................................................... 122 Logic Equations for a x16 Device ................................................................................................................ 122 CT Input Timing Requirements .................................................................................................................. 122 Post Package Repair and Soft Post Package Repair ........................................................................................... 124 Post Package Repair ................................................................................................................................... 124 PPR Row Repair ......................................................................................................................................... 124 PPR Row Repair - Entry .......................................................................................................................... 124 PPR Row Repair – WRA Initiated (REF Commands Allowed) .................................................................... 125 PPR Row Repair – WR Initiated (REF Commands NOT Allowed) ............................................................... 126 sPPR Row Repair ....................................................................................................................................... 128 PPR/sPPR Support Identifier ...................................................................................................................... 129 Target Row Refresh Mode ............................................................................................................................... 131 ACTIVATE Command .................................................................................................................................... 132 PRECHARGE Command ................................................................................................................................ 133 REFRESH Command ..................................................................................................................................... 133 Temperature-Controlled Refresh Mode .......................................................................................................... 135 TCR Mode – Normal Temperature Range .................................................................................................... 135 TCR Mode – Extended Temperature Range ................................................................................................. 135 Fine Granularity Refresh Mode ....................................................................................................................... 137 Mode Register and Command Truth Table .................................................................................................. 137 tREFI and tRFC Parameters ........................................................................................................................ 137 Changing Refresh Rate ............................................................................................................................... 140 Usage with TCR Mode ................................................................................................................................ 140 Self Refresh Entry and Exit ......................................................................................................................... 140 SELF REFRESH Operation .............................................................................................................................. 142 Self Refresh Abort ...................................................................................................................................... 144 Self Refresh Exit with NOP Command ......................................................................................................... 145 Power-Down Mode ........................................................................................................................................ 147 Power-Down Clarifications – Case 1 ........................................................................................................... 152 Power-Down Entry, Exit Timing with CAL ................................................................................................... 153 ODT Input Buffer Disable Mode for Power-Down ............................................................................................ 156 CRC Write Data Feature ................................................................................................................................. 158 CRC Write Data ......................................................................................................................................... 158 WRITE CRC DATA Operation ...................................................................................................................... 158 DBI_n and CRC Both Enabled .................................................................................................................... 159 DM_n and CRC Both Enabled .................................................................................................................... 159 DM_n and DBI_n Conflict During Writes with CRC Enabled ........................................................................ 159 CRC and Write Preamble Restrictions ......................................................................................................... 159 CRC Simultaneous Operation Restrictions .................................................................................................. 159 CRC Polynomial ........................................................................................................................................ 159 CRC Combinatorial Logic Equations .......................................................................................................... 160 Burst Ordering for BL8 ............................................................................................................................... 161 CRC Data Bit Mapping ............................................................................................................................... 161 CRC Enabled With BC4 .............................................................................................................................. 162 CRC with BC4 Data Bit Mapping ................................................................................................................ 162 CRC Equations for x8 Device in BC4 Mode with A2 = 0 and A2 = 1 ................................................................ 165 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 5 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features CRC Error Handling ................................................................................................................................... 166 CRC Write Data Flow Diagram ................................................................................................................... 168 Data Bus Inversion ........................................................................................................................................ 169 DBI During a WRITE Operation .................................................................................................................. 169 DBI During a READ Operation ................................................................................................................... 170 Data Mask ..................................................................................................................................................... 171 Programmable Preamble Modes and DQS Postambles .................................................................................... 172 WRITE Preamble Mode .............................................................................................................................. 172 READ Preamble Mode ............................................................................................................................... 176 READ Preamble Training ........................................................................................................................... 176 WRITE Postamble ...................................................................................................................................... 177 READ Postamble ....................................................................................................................................... 177 Bank Access Operation .................................................................................................................................. 179 READ Operation ............................................................................................................................................ 183 Read Timing Definitions ............................................................................................................................ 183 Read Timing – Clock-to-Data Strobe Relationship ....................................................................................... 184 Read Timing – Data Strobe-to-Data Relationship ........................................................................................ 185 tLZ(DQS), tLZ(DQ), tHZ(DQS), and tHZ(DQ) Calculations ............................................................................ 186 tRPRE Calculation ..................................................................................................................................... 188 tRPST Calculation ...................................................................................................................................... 189 READ Burst Operation ............................................................................................................................... 190 READ Operation Followed by Another READ Operation .............................................................................. 192 READ Operation Followed by WRITE Operation .......................................................................................... 197 READ Operation Followed by PRECHARGE Operation ................................................................................ 203 READ Operation with Read Data Bus Inversion (DBI) .................................................................................. 206 READ Operation with Command/Address Parity (CA Parity) ........................................................................ 207 READ Followed by WRITE with CRC Enabled .............................................................................................. 209 READ Operation with Command/Address Latency (CAL) Enabled ............................................................... 210 WRITE Operation .......................................................................................................................................... 212 Write Timing Definitions ........................................................................................................................... 212 Write Timing – Clock-to-Data Strobe Relationship ...................................................................................... 212 Write Timing – Data Strobe-to-Data Relationship ........................................................................................ 213 WRITE Burst Operation ............................................................................................................................. 217 WRITE Operation Followed by Another WRITE Operation ........................................................................... 219 WRITE Operation Followed by READ Operation .......................................................................................... 225 WRITE Operation Followed by PRECHARGE Operation ............................................................................... 229 WRITE Operation with WRITE DBI Enabled ................................................................................................ 232 WRITE Operation with CA Parity Enabled ................................................................................................... 234 WRITE Operation with Write CRC Enabled ................................................................................................. 235 Write Timing Violations ................................................................................................................................. 240 Motivation ................................................................................................................................................ 240 Data Setup and Hold Violations ................................................................................................................. 240 Strobe-to-Strobe and Strobe-to-Clock Violations ........................................................................................ 240 ZQ CALIBRATION Commands ....................................................................................................................... 241 On-Die Termination ...................................................................................................................................... 243 ODT Mode Register and ODT State Table ........................................................................................................ 243 ODT Read Disable State Table .................................................................................................................... 244 Synchronous ODT Mode ................................................................................................................................ 245 ODT Latency and Posted ODT .................................................................................................................... 245 Timing Parameters .................................................................................................................................... 245 ODT During Reads .................................................................................................................................... 247 Dynamic ODT ............................................................................................................................................... 248 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 6 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features Functional Description .............................................................................................................................. 248 Asynchronous ODT Mode .............................................................................................................................. 251 Electrical Specifications ................................................................................................................................. 252 Absolute Ratings ........................................................................................................................................ 252 DRAM Component Operating Temperature Range ...................................................................................... 252 Electrical Characteristics – AC and DC Operating Conditions .......................................................................... 253 Supply Operating Conditions ..................................................................................................................... 253 Leakages ................................................................................................................................................... 253 VREFCA Supply ............................................................................................................................................ 254 VREFDQ Supply and Calibration Ranges ....................................................................................................... 255 VREFDQ Ranges ........................................................................................................................................... 256 Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels .............................................. 257 RESET_n Input Levels ................................................................................................................................ 257 Command/Address Input Levels ................................................................................................................ 258 Data Receiver Input Requirements ............................................................................................................. 261 Connectivity Test (CT) Mode Input Levels .................................................................................................. 264 Electrical Characteristics – AC and DC Differential Input Measurement Levels ................................................. 268 Differential Inputs ..................................................................................................................................... 268 Single-Ended Requirements for CK Differential Signals ............................................................................... 269 Slew Rate Definitions for CK Differential Input Signals ................................................................................ 270 CK Differential Input Cross Point Voltage .................................................................................................... 271 DQS Differential Input Signal Definition and Swing Requirements .............................................................. 272 DQS Differential Input Cross Point Voltage ................................................................................................. 274 Slew Rate Definitions for DQS Differential Input Signals .............................................................................. 275 Electrical Characteristics – Overshoot and Undershoot Specifications ............................................................. 277 Address, Command, and Control Overshoot and Undershoot Specifications ................................................ 277 Clock Overshoot and Undershoot Specifications ......................................................................................... 278 Data, Strobe, and Mask Overshoot and Undershoot Specifications .............................................................. 279 Electrical Characteristics – AC and DC Output Measurement Levels ................................................................ 279 Single-Ended Outputs ............................................................................................................................... 279 Differential Outputs .................................................................................................................................. 281 Reference Load for AC Timing and Output Slew Rate ................................................................................... 282 Connectivity Test Mode Output Levels ........................................................................................................ 283 Electrical Characteristics – AC and DC Output Driver Characteristics ............................................................... 285 Output Driver Electrical Characteristics ..................................................................................................... 285 Output Driver Temperature and Voltage Sensitivity ..................................................................................... 288 Alert Driver ............................................................................................................................................... 288 Electrical Characteristics – On-Die Termination Characteristics ...................................................................... 289 ODT Levels and I-V Characteristics ............................................................................................................ 289 ODT Temperature and Voltage Sensitivity ................................................................................................... 291 ODT Timing Definitions ............................................................................................................................ 291 DRAM Package Electrical Specifications ......................................................................................................... 295 Thermal Characteristics ................................................................................................................................. 299 Current Specifications – Measurement Conditions .......................................................................................... 300 IDD, IPP, and IDDQ Measurement Conditions ................................................................................................ 300 IDD Definitions .......................................................................................................................................... 301 Current Specifications – Patterns and Test Conditions ..................................................................................... 305 Current Test Definitions and Patterns ......................................................................................................... 305 IDD Specifications ...................................................................................................................................... 314 Current Specifications – Limits ....................................................................................................................... 315 Speed Bin Tables ........................................................................................................................................... 319 Refresh Parameters By Device Density ............................................................................................................ 328 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 7 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features Electrical Characteristics and AC Timing Parameters ...................................................................................... 329 Electrical Characteristics and AC Timing Parameters: 2666 Through 3200 ........................................................ 341 EDY4016 Option and Exception Lists .............................................................................................................. 353 Mode Register Settings .............................................................................................................................. 353 Options Tables .............................................................................................................................................. 353 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 8 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features List of Figures Figure 1: 78-Ball x4, x8 Ball Assignments ........................................................................................................ 19 Figure 2: 96-Ball x16 Ball Assignments ............................................................................................................ 20 Figure 3: 78-Ball FBGA – x4, x8 "HX" .............................................................................................................. 24 Figure 4: 78-Ball FBGA – x4, x8 "RH" .............................................................................................................. 25 Figure 5: 96-Ball FBGA – x16 "HA" .................................................................................................................. 26 Figure 6: 96-Ball FBGA – x16 "GE" .................................................................................................................. 27 Figure 7: Simplified State Diagram ................................................................................................................. 28 Figure 8: RESET and Initialization Sequence at Power-On Ramping ................................................................. 33 Figure 9: RESET Procedure at Power Stable Condition ..................................................................................... 34 Figure 10: tMRD Timing ................................................................................................................................ 36 Figure 11: tMOD Timing ................................................................................................................................ 36 Figure 12: DLL-Off Mode Read Timing Operation ........................................................................................... 65 Figure 13: DLL Switch Sequence from DLL-On to DLL-Off .............................................................................. 67 Figure 14: DLL Switch Sequence from DLL-Off to DLL-On .............................................................................. 68 Figure 15: Write-Leveling Concept, Example 1 ................................................................................................ 70 Figure 16: Write-Leveling Concept, Example 2 ................................................................................................ 71 Figure 17: Write-Leveling Sequence (DQS Capturing CK LOW at T1 and CK HIGH at T2) .................................. 73 Figure 18: Write-Leveling Exit ........................................................................................................................ 74 Figure 19: CAL Timing Definition ................................................................................................................... 75 Figure 20: CAL Timing Example (Consecutive CS_n = LOW) ............................................................................ 75 Figure 21: CAL Enable Timing – tMOD_CAL ................................................................................................... 76 Figure 22: tMOD_CAL, MRS to Valid Command Timing with CAL Enabled ....................................................... 76 Figure 23: CAL Enabling MRS to Next MRS Command, tMRD_CAL .................................................................. 77 Figure 24: tMRD_CAL, Mode Register Cycle Time With CAL Enabled ............................................................... 77 Figure 25: Consecutive READ BL8, CAL3, 1tCK Preamble, Different Bank Group ............................................... 78 Figure 26: Consecutive READ BL8, CAL4, 1tCK Preamble, Different Bank Group ............................................... 78 Figure 27: Auto Self Refresh Ranges ................................................................................................................ 81 Figure 28: MPR Block Diagram ....................................................................................................................... 82 Figure 29: MPR READ Timing ........................................................................................................................ 88 Figure 30: MPR Back-to-Back READ Timing ................................................................................................... 89 Figure 31: MPR READ-to-WRITE Timing ........................................................................................................ 90 Figure 32: MPR WRITE and WRITE-to-READ Timing ...................................................................................... 91 Figure 33: MPR Back-to-Back WRITE Timing .................................................................................................. 92 Figure 34: REFRESH Timing ........................................................................................................................... 92 Figure 35: READ-to-REFRESH Timing ............................................................................................................ 93 Figure 36: WRITE-to-REFRESH Timing .......................................................................................................... 93 Figure 37: Clock Mode Change from 1/2 Rate to 1/4 Rate (Initialization) .......................................................... 96 Figure 38: Clock Mode Change After Exiting Self Refresh ................................................................................. 96 Figure 39: Comparison Between Gear-Down Disable and Gear-Down Enable .................................................. 97 Figure 40: Maximum Power-Saving Mode Entry .............................................................................................. 98 Figure 41: Maximum Power-Saving Mode Entry with PDA ............................................................................... 99 Figure 42: Maintaining Maximum Power-Saving Mode with CKE Transition .................................................... 99 Figure 43: Maximum Power-Saving Mode Exit ............................................................................................... 100 Figure 44: Command/Address Parity Operation ............................................................................................. 101 Figure 45: Command/Address Parity During Normal Operation ..................................................................... 103 Figure 46: Persistent CA Parity Error Checking Operation ............................................................................... 104 Figure 47: CA Parity Error Checking – SRE Attempt ........................................................................................ 104 Figure 48: CA Parity Error Checking – SRX Attempt ........................................................................................ 105 Figure 49: CA Parity Error Checking – PDE/PDX ............................................................................................ 105 Figure 50: Parity Entry Timing Example – tMRD_PAR ..................................................................................... 106 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 9 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features Figure 51: Parity Entry Timing Example – tMOD_PAR ..................................................................................... 106 Figure 52: Parity Exit Timing Example – tMRD_PAR ....................................................................................... 106 Figure 53: Parity Exit Timing Example – tMOD_PAR ....................................................................................... 107 Figure 54: CA Parity Flow Diagram ................................................................................................................ 108 Figure 55: PDA Operation Enabled, BL8 ........................................................................................................ 110 Figure 56: PDA Operation Enabled, BC4 ........................................................................................................ 110 Figure 57: MRS PDA Exit ............................................................................................................................... 111 Figure 58: V REFDQ Voltage Range ................................................................................................................... 112 Figure 59: Example of V REF Set Tolerance and Step Size .................................................................................. 114 Figure 60: V REFDQ Timing Diagram for V REF,time Parameter .............................................................................. 115 Figure 61: V REFDQ Training Mode Entry and Exit Timing Diagram ................................................................... 116 Figure 62: V REF Step: Single Step Size Increment Case .................................................................................... 117 Figure 63: V REF Step: Single Step Size Decrement Case ................................................................................... 117 Figure 64: V REF Full Step: From V REF,min to V REF,maxCase .................................................................................. 118 Figure 65: V REF Full Step: From V REF,max to V REF,minCase .................................................................................. 118 Figure 66: V REFDQ Equivalent Circuit ............................................................................................................. 119 Figure 67: Connectivity Test Mode Entry ....................................................................................................... 123 Figure 68: PPR WRA – Entry .......................................................................................................................... 126 Figure 69: PPR WRA – Repair and Exit ........................................................................................................... 126 Figure 70: PPR WR – Entry ............................................................................................................................ 127 Figure 71: PPR WR – Repair and Exit .............................................................................................................. 127 Figure 72: sPPR – Entry, Repair, and Exit ........................................................................................................ 129 Figure 73: tRRD Timing ................................................................................................................................ 132 Figure 74: tFAW Timing ................................................................................................................................. 132 Figure 75: REFRESH Command Timing ......................................................................................................... 134 Figure 76: Postponing REFRESH Commands (Example) ................................................................................. 134 Figure 77: Pulling In REFRESH Commands (Example) ................................................................................... 134 Figure 78: TCR Mode Example 1 ..................................................................................................................... 136 Figure 79: 4Gb with Fine Granularity Refresh Mode Example ......................................................................... 139 Figure 80: OTF REFRESH Command Timing ................................................................................................. 140 Figure 81: Self Refresh Entry/Exit Timing ...................................................................................................... 143 Figure 82: Self Refresh Entry/Exit Timing with CAL Mode ............................................................................... 144 Figure 83: Self Refresh Abort ......................................................................................................................... 145 Figure 84: Self Refresh Exit with NOP Command ............................................................................................ 146 Figure 85: Active Power-Down Entry and Exit ................................................................................................ 148 Figure 86: Power-Down Entry After Read and Read with Auto Precharge ......................................................... 149 Figure 87: Power-Down Entry After Write and Write with Auto Precharge ........................................................ 149 Figure 88: Power-Down Entry After Write ...................................................................................................... 150 Figure 89: Precharge Power-Down Entry and Exit .......................................................................................... 150 Figure 90: REFRESH Command to Power-Down Entry ................................................................................... 151 Figure 91: Active Command to Power-Down Entry ......................................................................................... 151 Figure 92: PRECHARGE/PRECHARGE ALL Command to Power-Down Entry .................................................. 152 Figure 93: MRS Command to Power-Down Entry ........................................................................................... 152 Figure 94: Power-Down Entry/Exit Clarifications – Case 1 .............................................................................. 153 Figure 95: Active Power-Down Entry and Exit Timing with CAL ...................................................................... 154 Figure 96: REFRESH Command to Power-Down Entry with CAL ..................................................................... 155 Figure 97: ODT Power-Down Entry with ODT Buffer Disable Mode ................................................................ 156 Figure 98: ODT Power-Down Exit with ODT Buffer Disable Mode ................................................................... 157 Figure 99: CRC Write Data Operation ............................................................................................................ 158 Figure 100: CRC Error Reporting ................................................................................................................... 167 Figure 101: CA Parity Flow Diagram .............................................................................................................. 168 Figure 102: 1tCK vs. 2tCK WRITE Preamble Mode ........................................................................................... 172 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 10 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features Figure 103: 1tCK vs. 2tCK WRITE Preamble Mode, tCCD = 4 ............................................................................ 174 Figure 104: 1tCK vs. 2tCK WRITE Preamble Mode, tCCD = 5 ............................................................................ 175 Figure 105: 1tCK vs. 2 tCK WRITE Preamble Mode, tCCD = 6 ........................................................................... 175 Figure 106: 1tCK vs. 2tCK READ Preamble Mode ............................................................................................ 176 Figure 107: READ Preamble Training ............................................................................................................. 177 Figure 108: WRITE Postamble ....................................................................................................................... 177 Figure 109: READ Postamble ........................................................................................................................ 178 Figure 110: Bank Group x4/x8 Block Diagram ................................................................................................ 179 Figure 111: READ Burst tCCD_S and tCCD_L Examples .................................................................................. 180 Figure 112: Write Burst tCCD_S and tCCD_L Examples ................................................................................... 180 Figure 113: tRRD Timing ............................................................................................................................... 181 Figure 114: tWTR_S Timing (WRITE-to-READ, Different Bank Group, CRC and DM Disabled) ......................... 181 Figure 115: tWTR_L Timing (WRITE-to-READ, Same Bank Group, CRC and DM Disabled) .............................. 182 Figure 116: Read Timing Definition ............................................................................................................... 184 Figure 117: Clock-to-Data Strobe Relationship .............................................................................................. 185 Figure 118: Data Strobe-to-Data Relationship ................................................................................................ 186 Figure 119: tLZ and tHZ Method for Calculating Transitions and Endpoints .................................................... 187 Figure 120: tRPRE Method for Calculating Transitions and Endpoints ............................................................. 188 Figure 121: tRPST Method for Calculating Transitions and Endpoints ............................................................. 189 Figure 122: READ Burst Operation, RL = 11 (AL = 0, CL = 11, BL8) ................................................................... 190 Figure 123: READ Burst Operation, RL = 21 (AL = 10, CL = 11, BL8) ................................................................. 191 Figure 124: Consecutive READ (BL8) with 1tCK Preamble in Different Bank Group .......................................... 192 Figure 125: Consecutive READ (BL8) with 2tCK Preamble in Different Bank Group .......................................... 192 Figure 126: Nonconsecutive READ (BL8) with 1tCK Preamble in Same or Different Bank Group ....................... 193 Figure 127: Nonconsecutive READ (BL8) with 2tCK Preamble in Same or Different Bank Group ....................... 193 Figure 128: READ (BC4) to READ (BC4) with 1tCK Preamble in Different Bank Group ...................................... 194 Figure 129: READ (BC4) to READ (BC4) with 2tCK Preamble in Different Bank Group ...................................... 194 Figure 130: READ (BL8) to READ (BC4) OTF with 1tCK Preamble in Different Bank Group ............................... 195 Figure 131: READ (BL8) to READ (BC4) OTF with 2tCK Preamble in Different Bank Group ............................... 195 Figure 132: READ (BC4) to READ (BL8) OTF with 1tCK Preamble in Different Bank Group ............................... 196 Figure 133: READ (BC4) to READ (BL8) OTF with 2tCK Preamble in Different Bank Group ............................... 196 Figure 134: READ (BL8) to WRITE (BL8) with 1 tCK Preamble in Same or Different Bank Group ........................ 197 Figure 135: READ (BL8) to WRITE (BL8) with 2 tCK Preamble in Same or Different Bank Group ........................ 197 Figure 136: READ (BC4) OTF to WRITE (BC4) OTF with 1 tCK Preamble in Same or Different Bank Group ......... 198 Figure 137: READ (BC4) OTF to WRITE (BC4) OTF with 2 tCK Preamble in Same or Different Bank Group ......... 199 Figure 138: READ (BC4) Fixed to WRITE (BC4) Fixed with 1 tCK Preamble in Same or Different Bank Group ..... 199 Figure 139: READ (BC4) Fixed to WRITE (BC4) Fixed with 2 tCK Preamble in Same or Different Bank Group ..... 200 Figure 140: READ (BC4) to WRITE (BL8) OTF with 1 tCK Preamble in Same or Different Bank Group ................ 201 Figure 141: READ (BC4) to WRITE (BL8) OTF with 2 tCK Preamble in Same or Different Bank Group ................ 201 Figure 142: READ (BL8) to WRITE (BC4) OTF with 1 tCK Preamble in Same or Different Bank Group ................ 202 Figure 143: READ (BL8) to WRITE (BC4) OTF with 2 tCK Preamble in Same or Different Bank Group ................ 202 Figure 144: READ to PRECHARGE with 1tCK Preamble .................................................................................. 203 Figure 145: READ to PRECHARGE with 2tCK Preamble .................................................................................. 204 Figure 146: READ to PRECHARGE with Additive Latency and 1tCK Preamble .................................................. 204 Figure 147: READ with Auto Precharge and 1tCK Preamble ............................................................................ 205 Figure 148: READ with Auto Precharge, Additive Latency, and 1tCK Preamble ................................................. 206 Figure 149: Consecutive READ (BL8) with 1tCK Preamble and DBI in Different Bank Group ............................ 206 Figure 150: Consecutive READ (BL8) with 1tCK Preamble and CA Parity in Different Bank Group .................... 207 Figure 151: READ (BL8) to WRITE (BL8) with 1 tCK Preamble and CA Parity in Same or Different Bank Group ... 208 Figure 152: READ (BL8) to WRITE (BL8 or BC4: OTF) with 1 tCK Preamble and Write CRC in Same or Different Bank Group ............................................................................................................................................... 209 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 11 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features Figure 153: READ (BC4: Fixed) to WRITE (BC4: Fixed) with 1 tCK Preamble and Write CRC in Same or Different Bank Group ............................................................................................................................................... 210 Figure 154: Consecutive READ (BL8) with CAL (3tCK) and 1tCK Preamble in Different Bank Group .................. 210 Figure 155: Consecutive READ (BL8) with CAL (4tCK) and 1tCK Preamble in Different Bank Group .................. 211 Figure 156: Write Timing Definition .............................................................................................................. 213 Figure 157: Rx Compliance Mask .................................................................................................................. 214 Figure 158: V CENT_DQ VREFDQ Voltage Variation .............................................................................................. 214 Figure 159: Rx Mask DQ-to-DQS Timings ...................................................................................................... 215 Figure 160: Rx Mask DQ-to-DQS DRAM-Based Timings ................................................................................. 216 Figure 161: Example of Data Input Requirements Without Training ................................................................ 217 Figure 162: WRITE Burst Operation, WL = 9 (AL = 0, CWL = 9, BL8) ................................................................. 218 Figure 163: WRITE Burst Operation, WL = 19 (AL = 10, CWL = 9, BL8) ............................................................. 219 Figure 164: Consecutive WRITE (BL8) with 1 tCK Preamble in Different Bank Group ........................................ 219 Figure 165: Consecutive WRITE (BL8) with 2 tCK Preamble in Different Bank Group ........................................ 220 Figure 166: Nonconsecutive WRITE (BL8) with 1 tCK Preamble in Same or Different Bank Group ..................... 221 Figure 167: Nonconsecutive WRITE (BL8) with 2 tCK Preamble in Same or Different Bank Group ..................... 221 Figure 168: WRITE (BC4) OTF to WRITE (BC4) OTF with 1 tCK Preamble in Different Bank Group .................... 222 Figure 169: WRITE (BC4) OTF to WRITE (BC4) OTF with 2 tCK Preamble in Different Bank Group .................... 223 Figure 170: WRITE (BC4) Fixed to WRITE (BC4) Fixed with 1 tCK Preamble in Different Bank Group ................. 223 Figure 171: WRITE (BL8) to WRITE (BC4) OTF with 1 tCK Preamble in Different Bank Group ............................ 224 Figure 172: WRITE (BC4) OTF to WRITE (BL8) with 1 tCK Preamble in Different Bank Group ............................ 225 Figure 173: WRITE (BL8) to READ (BL8) with 1 tCK Preamble in Different Bank Group ..................................... 225 Figure 174: WRITE (BL8) to READ (BL8) with 1 tCK Preamble in Same Bank Group .......................................... 226 Figure 175: WRITE (BC4) OTF to READ (BC4) OTF with 1 tCK Preamble in Different Bank Group ...................... 227 Figure 176: WRITE (BC4) OTF to READ (BC4) OTF with 1 tCK Preamble in Same Bank Group ........................... 227 Figure 177: WRITE (BC4) Fixed to READ (BC4) Fixed with 1 tCK Preamble in Different Bank Group ................. 228 Figure 178: WRITE (BC4) Fixed to READ (BC4) Fixed with 1 tCK Preamble in Same Bank Group ....................... 228 Figure 179: WRITE (BL8/BC4-OTF) to PRECHARGE with 1 tCK Preamble ........................................................ 229 Figure 180: WRITE (BC4-Fixed) to PRECHARGE with 1 tCK Preamble .............................................................. 230 Figure 181: WRITE (BL8/BC4-OTF) to Auto PRECHARGE with 1 tCK Preamble ................................................ 230 Figure 182: WRITE (BC4-Fixed) to Auto PRECHARGE with 1 tCK Preamble ...................................................... 231 Figure 183: WRITE (BL8/BC4-OTF) with 1 tCK Preamble and DBI ................................................................... 232 Figure 184: WRITE (BC4-Fixed) with 1 tCK Preamble and DBI ......................................................................... 233 Figure 185: Consecutive Write (BL8) with 1 tCK Preamble and CA Parity in Different Bank Group ..................... 234 Figure 186: Consecutive WRITE (BL8/BC4-OTF) with 1 tCK Preamble and Write CRC in Same or Different Bank Group ....................................................................................................................................................... 235 Figure 187: Consecutive WRITE (BC4-Fixed) with 1 tCK Preamble and Write CRC in Same or Different Bank Group ....................................................................................................................................................... 236 Figure 188: Nonconsecutive WRITE (BL8/BC4-OTF) with 1 tCK Preamble and Write CRC in Same or Different Bank Group ............................................................................................................................................... 237 Figure 189: Nonconsecutive WRITE (BL8/BC4-OTF) with 2 tCK Preamble and Write CRC in Same or Different Bank Group ............................................................................................................................................... 238 Figure 190: WRITE (BL8/BC4-OTF/Fixed) with 1 tCK Preamble and Write CRC in Same or Different Bank Group ... 239 Figure 191: ZQ Calibration Timing ................................................................................................................ 242 Figure 192: Functional Representation of ODT .............................................................................................. 243 Figure 193: Synchronous ODT Timing with BL8 ............................................................................................. 246 Figure 194: Synchronous ODT with BC4 ........................................................................................................ 246 Figure 195: ODT During Reads ...................................................................................................................... 247 Figure 196: Dynamic ODT (1t CK Preamble; CL = 14, CWL = 11, BL = 8, AL = 0, CRC Disabled) .......................... 249 Figure 197: Dynamic ODT Overlapped with RTT(NOM) (CL = 14, CWL = 11, BL = 8, AL = 0, CRC Disabled) .......... 250 Figure 198: Asynchronous ODT Timings with DLL Off ................................................................................... 251 Figure 199: V REFDQ Voltage Range .................................................................................................................. 254 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 12 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features Figure 200: Figure 201: Figure 202: Figure 203: Figure 204: Figure 205: Figure 206: Figure 207: Figure 208: Figure 209: Figure 210: Figure 211: Figure 212: Figure 213: Figure 214: Figure 215: Figure 216: Figure 217: Figure 218: Figure 219: Figure 220: Figure 221: Figure 222: Figure 223: Figure 224: Figure 225: Figure 226: Figure 227: Figure 228: Figure 229: Figure 230: Figure 231: Figure 232: Figure 233: Figure 234: Figure 235: RESET_n Input Slew Rate Definition ............................................................................................ 258 Single-Ended Input Slew Rate Definition ..................................................................................... 260 DQ Slew Rate Definitions ............................................................................................................ 261 Rx Mask Relative to tDS/tDH ....................................................................................................... 263 Rx Mask Without Write Training .................................................................................................. 264 TEN Input Slew Rate Definition ................................................................................................... 265 CT Type-A Input Slew Rate Definition .......................................................................................... 265 CT Type-B Input Slew Rate Definition .......................................................................................... 266 CT Type-C Input Slew Rate Definition .......................................................................................... 267 CT Type-D Input Slew Rate Definition ......................................................................................... 267 Differential AC Swing and “Time Exceeding AC-Level” tDVAC ....................................................... 268 Single-Ended Requirements for CK .............................................................................................. 270 Differential Input Slew Rate Definition for CK_t, CK_c .................................................................. 271 V IX(CK) Definition ........................................................................................................................ 271 Differential Input Signal Definition for DQS_t, DQS_c .................................................................. 272 DQS_t, DQS_c Input Peak Voltage Calculation and Range of Exempt non-Monotonic Signaling ..... 273 V IXDQS Definition ........................................................................................................................ 274 Differential Input Slew Rate and Input Level Definition for DQS_t, DQS_c ..................................... 275 ADDR, CMD, CNTL Overshoot and Undershoot Definition ........................................................... 277 CK Overshoot and Undershoot Definition .................................................................................... 278 Data, Strobe, and Mask Overshoot and Undershoot Definition ..................................................... 279 Single-ended Output Slew Rate Definition ................................................................................... 280 Differential Output Slew Rate Definition ...................................................................................... 282 Reference Load For AC Timing and Output Slew Rate ................................................................... 283 Connectivity Test Mode Reference Test Load ................................................................................ 283 Connectivity Test Mode Output Slew Rate Definition .................................................................... 284 Output Driver: Definition of Voltages and Currents ...................................................................... 285 Alert Driver ................................................................................................................................ 288 ODT Definition of Voltages and Currents ..................................................................................... 289 ODT Timing Reference Load ....................................................................................................... 291 tADC Definition with Direct ODT Control .................................................................................... 293 tADC Definition with Dynamic ODT Control ................................................................................ 293 tAOFAS and tAONAS Definitions .................................................................................................. 294 Thermal Measurement Point ....................................................................................................... 299 Measurement Setup and Test Load for I DDx, IDDPx, and IDDQx ........................................................ 301 Correlation: Simulated Channel I/O Power to Actual Channel I/O Power ....................................... 301 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 13 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features List of Tables Table 1: Key Timing Parameters ....................................................................................................................... 2 Table 2: Addressing ......................................................................................................................................... 2 Table 3: Ball Descriptions .............................................................................................................................. 21 Table 4: State Diagram Command Definitions ................................................................................................ 29 Table 5: Address Pin Mapping ........................................................................................................................ 38 Table 6: MR0 Register Definition .................................................................................................................... 38 Table 7: Burst Type and Burst Order ............................................................................................................... 40 Table 8: Address Pin Mapping ........................................................................................................................ 42 Table 9: MR1 Register Definition .................................................................................................................... 42 Table 10: Additive Latency (AL) Settings ......................................................................................................... 44 Table 11: TDQS Function Matrix .................................................................................................................... 45 Table 12: Address Pin Mapping ...................................................................................................................... 46 Table 13: MR2 Register Definition .................................................................................................................. 46 Table 14: Address Pin Mapping ...................................................................................................................... 49 Table 15: MR3 Register Definition .................................................................................................................. 49 Table 16: Address Pin Mapping ...................................................................................................................... 52 Table 17: MR4 Register Definition .................................................................................................................. 52 Table 18: Address Pin Mapping ...................................................................................................................... 56 Table 19: MR5 Register Definition .................................................................................................................. 56 Table 20: Address Pin Mapping ...................................................................................................................... 59 Table 21: MR6 Register Definition .................................................................................................................. 59 Table 22: Truth Table – Command .................................................................................................................. 61 Table 23: Truth Table – CKE ........................................................................................................................... 63 Table 24: MR Settings for Leveling Procedures ................................................................................................ 71 Table 25: DRAM TERMINATION Function in Leveling Mode ........................................................................... 71 Table 26: Auto Self Refresh Mode ................................................................................................................... 80 Table 27: MR3 Setting for the MPR Access Mode ............................................................................................. 82 Table 28: DRAM Address to MPR UI Translation ............................................................................................. 82 Table 29: MPR Page and MPRx Definitions ..................................................................................................... 83 Table 30: MPR Readout Serial Format ............................................................................................................. 85 Table 31: MPR Readout – Parallel Format ....................................................................................................... 86 Table 32: MPR Readout Staggered Format, x4 ................................................................................................. 87 Table 33: MPR Readout Staggered Format, x4 – Consecutive READs ................................................................ 87 Table 34: MPR Readout Staggered Format, x8 and x16 ..................................................................................... 88 Table 35: Mode Register Setting for CA Parity ................................................................................................. 103 Table 36: V REFDQ Range and Levels ................................................................................................................ 113 Table 37: V REFDQ Settings (VDDQ = 1.2V) ......................................................................................................... 119 Table 38: Connectivity Mode Pin Description and Switching Levels ................................................................ 121 Table 39: PPR MR0 Guard Key Settings .......................................................................................................... 125 Table 40: DDR4 PPR Timing Parameters DDR4-1600 through DDR4-3200 ....................................................... 128 Table 41: DDR4 sPPR Timing Parameters DDR4-1600 through DDR4-3200 ..................................................... 129 Table 42: DDR4 Repair Mode Support Identifier ............................................................................................ 129 Table 43: MAC Encoding of MPR Page 3 MPR3 ............................................................................................... 131 Table 44: Normal tREFI Refresh (TCR Disabled) ............................................................................................. 135 Table 45: Normal tREFI Refresh (TCR Enabled) .............................................................................................. 136 Table 46: MRS Definition .............................................................................................................................. 137 Table 47: REFRESH Command Truth Table .................................................................................................... 137 Table 48: tREFI and tRFC Parameters ............................................................................................................. 138 Table 49: Power-Down Entry Definitions ....................................................................................................... 147 Table 50: CRC Error Detection Coverage ........................................................................................................ 159 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 14 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features Table 51: CRC Data Mapping for x4 Devices, BL8 ........................................................................................... 161 Table 52: CRC Data Mapping for x8 Devices, BL8 ........................................................................................... 161 Table 53: CRC Data Mapping for x16 Devices, BL8 ......................................................................................... 162 Table 54: CRC Data Mapping for x4 Devices, BC4 ........................................................................................... 162 Table 55: CRC Data Mapping for x8 Devices, BC4 ........................................................................................... 163 Table 56: CRC Data Mapping for x16 Devices, BC4 ......................................................................................... 164 Table 57: DBI vs. DM vs. TDQS Function Matrix ............................................................................................. 169 Table 58: DBI Write, DQ Frame Format (x8) ................................................................................................... 169 Table 59: DBI Write, DQ Frame Format (x16) ................................................................................................. 169 Table 60: DBI Read, DQ Frame Format (x8) .................................................................................................... 170 Table 61: DBI Read, DQ Frame Format (x16) .................................................................................................. 170 Table 62: DM vs. TDQS vs. DBI Function Matrix ............................................................................................. 171 Table 63: Data Mask, DQ Frame Format (x8) .................................................................................................. 171 Table 64: Data Mask, DQ Frame Format (x16) ................................................................................................ 171 Table 65: CWL Selection ............................................................................................................................... 173 Table 66: DDR4 Bank Group Timing Examples .............................................................................................. 179 Table 67: Termination State Table ................................................................................................................. 244 Table 68: Read Termination Disable Window ................................................................................................. 244 Table 69: ODT Latency at DDR4-1600/-1866/-2133/-2400/-2666/-3200 .......................................................... 245 Table 70: Dynamic ODT Latencies and Timing (1 tCK Preamble Mode and CRC Disabled) ................................ 248 Table 71: Dynamic ODT Latencies and Timing with Preamble Mode and CRC Mode Matrix ............................ 249 Table 72: Absolute Maximum Ratings ............................................................................................................ 252 Table 73: Temperature Range ........................................................................................................................ 252 Table 74: Recommended Supply Operating Conditions .................................................................................. 253 Table 75: V DD Slew Rate ................................................................................................................................ 253 Table 76: Leakages ....................................................................................................................................... 254 Table 77: V REFDQ Specification ...................................................................................................................... 256 Table 78: V REFDQ Range and Levels ................................................................................................................ 257 Table 79: RESET_n Input Levels (CMOS) ....................................................................................................... 257 Table 80: Command and Address Input Levels: DDR4-1600 Through DDR4-2400 ........................................... 258 Table 81: Command and Address Input Levels: DDR4-2666 ............................................................................ 259 Table 82: Command and Address Input Levels: DDR4-2933 and DDR4-3200 ................................................... 259 Table 83: Single-Ended Input Slew Rates ....................................................................................................... 259 Table 84: DQ Input Receiver Specifications .................................................................................................... 262 Table 85: Rx Mask andtDS/tDH Without Write Training .................................................................................. 264 Table 86: TEN Input Levels (CMOS) .............................................................................................................. 264 Table 87: CT Type-A Input Levels .................................................................................................................. 265 Table 88: CT Type-B Input Levels .................................................................................................................. 266 Table 89: CT Type-C Input Levels (CMOS) ..................................................................................................... 266 Table 90: CT Type-D Input Levels .................................................................................................................. 267 Table 91: Differential Input Swing Requirements for CK_t, CK_c ..................................................................... 268 Table 92: Minimum Time AC Time tDVAC for CK ........................................................................................... 269 Table 93: Single-Ended Requirements for CK ................................................................................................. 270 Table 94: CK Differential Input Slew Rate Definition ...................................................................................... 270 Table 95: Cross Point Voltage For CK Differential Input Signals at DDR4-1600 through DDR4-2400 .................. 272 Table 96: Cross Point Voltage For CK Differential Input Signals at DDR4-2666 through DDR4-3200 .................. 272 Table 97: DDR4-1600 through DDR4-2400 Differential Input Swing Requirements for DQS_t, DQS_c .............. 273 Table 98: DDR4-2633 through DDR4-3200 Differential Input Swing Requirements for DQS_t, DQS_c .............. 273 Table 99: Cross Point Voltage For Differential Input Signals DQS .................................................................... 274 Table 100: DQS Differential Input Slew Rate Definition .................................................................................. 275 Table 101: DDR4-1600 through DDR4-2400 Differential Input Slew Rate and Input Levels for DQS_t, DQS_c ... 275 Table 102: DDR4-2666 through DDR4-3200 Differential Input Slew Rate and Input Levels for DQS_t, DQS_c ... 276 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 15 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Features Table 103: Table 104: Table 105: Table 106: Table 107: Table 108: Table 109: Table 110: Table 111: Table 112: Table 113: Table 114: Table 115: Table 116: Table 117: Table 118: Table 119: Table 120: Table 121: Table 122: Table 123: Table 124: Table 125: Table 126: Table 127: Table 128: Table 129: Table 130: Table 131: Table 132: Table 133: Table 134: Table 135: Table 136: Table 137: Table 138: Table 139: Table 140: Table 141: Table 142: Table 143: Table 144: Table 145: Table 146: Table 147: Table 148: Table 149: Table 150: Table 151: Table 152: Table 153: ADDR, CMD, CNTL Overshoot and Undershoot/Specifications ...................................................... 277 CK Overshoot and Undershoot/ Specifications .............................................................................. 278 Data, Strobe, and Mask Overshoot and Undershoot/ Specifications ................................................ 279 Single-Ended Output Levels ......................................................................................................... 279 Single-Ended Output Slew Rate Definition .................................................................................... 280 Single-Ended Output Slew Rate .................................................................................................... 281 Differential Output Levels ............................................................................................................. 281 Differential Output Slew Rate Definition ....................................................................................... 281 Differential Output Slew Rate ....................................................................................................... 282 Connectivity Test Mode Output Levels .......................................................................................... 283 Connectivity Test Mode Output Slew Rate ..................................................................................... 284 Strong Mode (34Ω) Output Driver Electrical Characteristics ........................................................... 286 Weak Mode (48Ω) Output Driver Electrical Characteristics ............................................................. 287 Output Driver Sensitivity Definitions ............................................................................................ 288 Output Driver Voltage and Temperature Sensitivity ....................................................................... 288 Alert Driver Voltage ...................................................................................................................... 289 ODT DC Characteristics ............................................................................................................... 290 ODT Sensitivity Definitions .......................................................................................................... 291 ODT Voltage and Temperature Sensitivity ..................................................................................... 291 ODT Timing Definitions ............................................................................................................... 292 Reference Settings for ODT Timing Measurements ........................................................................ 292 DRAM Package Electrical Specifications for x4 and x8 Devices ....................................................... 295 DRAM Package Electrical Specifications for x16 Devices ................................................................ 296 Pad Input/Output Capacitance ..................................................................................................... 298 Thermal Characteristics ............................................................................................................... 299 Basic IDD, IPP, and IDDQ Measurement Conditions .......................................................................... 301 IDD0 and IPP0 Measurement-Loop Pattern1 .................................................................................... 305 IDD1 Measurement-Loop Pattern1 ................................................................................................. 306 IDD2N, IDD3N, and IPP3P Measurement-Loop Pattern1 ...................................................................... 307 IDD2NT and IDDQ2NT Measurement-Loop Pattern1 ........................................................................... 308 IDD4R and IDDQ4R Measurement-Loop Pattern1 .............................................................................. 309 IDD4W Measurement-Loop Pattern1 ............................................................................................... 310 IDD4Wc Measurement-Loop Pattern1 .............................................................................................. 311 IDD5b Measurement-Loop Pattern1 ................................................................................................ 312 IDD7 Measurement-Loop Pattern1 ................................................................................................. 313 Timings used for I DD, IPP, and IDDQ Measurement-Loop Patterns .................................................... 314 IDD, IPP, and IDDQ Current Limits – Rev. A ....................................................................................... 315 IDD, IPP, and IDDQ Current Limits – Rev. B ....................................................................................... 316 DDR4-1600 Speed Bins and Operating Conditions ......................................................................... 319 DDR4-1866 Speed Bins and Operating Conditions ......................................................................... 320 DDR4-2133 Speed Bins and Operating Conditions ......................................................................... 321 DDR4-2400 Speed Bins and Operating Conditions ......................................................................... 322 DDR4-2666 Speed Bins and Operating Conditions ......................................................................... 323 DDR4-2933 Speed Bins and Operating Conditions ......................................................................... 324 DDR4-3200 Speed Bins and Operating Conditions ......................................................................... 326 Refresh Parameters by Device Density ........................................................................................... 328 Electrical Characteristics and AC Timing Parameters: DDR4-1600 through DDR4-2400 ................... 329 Electrical Characteristics and AC Timing Parameters ..................................................................... 341 Die Revision Options .................................................................................................................... 353 Speed Options ............................................................................................................................. 354 Width Options ............................................................................................................................. 354 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 16 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM General Notes and Description General Notes and Description Description The DDR4 SDRAM is a high-speed dynamic random-access memory internally configured as an eight-bank DRAM for the x16 configuration and as a 16-bank DRAM for the x4 and x8 configurations. The DDR4 SDRAM uses an 8n-prefetch architecture to achieve high-speed operation. The 8n-prefetch architecture is combined with an interface designed to transfer two data words per clock cycle at the I/O pins. A single READ or WRITE operation for the DDR4 SDRAM consists of a single 8n-bit wide, four-clock data transfer at the internal DRAM core and two corresponding n-bit wide, one-half-clock-cycle data transfers at the I/O pins. on page Industrial Temperature An industrial temperature (IT) device option requires that the case temperature not exceed below –40°C or above 95°C. JEDEC specifications require the refresh rate to double when T C exceeds 85°C; this also requires use of the high-temperature self refresh option. Additionally, ODT resistance and the input/output impedance must be derated when operating outside of the commercial temperature range, when T C is between -40°C and 0°C. General Notes • The functionality and the timing specifications discussed in this data sheet are for the DLL enable mode of operation (normal operation), unless specifically stated otherwise. • Throughout the data sheet, the various figures and text refer to DQs as "DQ." The DQ term is to be interpreted as any and all DQ collectively, unless specifically stated otherwise. • The terms "_t" and "_c" are used to represent the true and complement of a differential signal pair. These terms replace the previously used notation of "#" and/or overbar characters. For example, differential data strobe pair DQS, DQS# is now referred to as DQS_t, DQS_c. • The term "_n" is used to represent a signal that is active LOW and replaces the previously used "#" and/or overbar characters. For example: CS# is now referred to as CS_n. • The terms "DQS" and "CK" found throughout the data sheet are to be interpreted as DQS_t, DQS_c and CK_t, CK_c respectively, unless specifically stated otherwise. • Complete functionality may be described throughout the entire document; any page or diagram may have been simplified to convey a topic and may not be inclusive of all requirements. • Any specific requirement takes precedence over a general statement. • Any functionality not specifically stated here within is considered undefined, illegal, and not supported, and can result in unknown operation. • Addressing is denoted as BG[n] for bank group, BA[n] for bank address, and A[n] for row/col address. • The NOP command is not allowed, except when exiting maximum power savings mode or when entering gear-down mode, and only a DES command should be used. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 17 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM General Notes and Description • Not all features described within this document may be available on the Rev. A (first) version. • Not all specifications listed are finalized industry standards; best conservative estimates have been provided when an industry standard has not been finalized. • Although it is implied throughout the specification, the DRAM must be used after V DD has reached the stable power-on level, which is achieved by toggling CKE at least once every 8192 × tREFI. However, in the event CKE is fixed HIGH, toggling CS_n at least once every 8192 × tREFI is an acceptable alternative. Placing the DRAM into self refresh mode also alleviates the need to toggle CKE. • Not all features designated in the data sheet may be supported by earlier die revisions due to late definition by JEDEC. Definitions of the Device-Pin Signal Level • • • • HIGH: A device pin is driving the logic 1 state. LOW: A device pin is driving the logic 0 state. High-Z: A device pin is tri-state. ODT: A device pin terminates with the ODT setting, which could be terminating or tristate depending on the mode register setting. Definitions of the Bus Signal Level • HIGH: One device on the bus is HIGH, and all other devices on the bus are either ODT or High-Z. The voltage level on the bus is nominally V DDQ. • LOW: One device on the bus is LOW, and all other devices on the bus are either ODT or High-Z. The voltage level on the bus is nominally V OL(DC) if ODT was enabled, or VSSQ if High-Z. • High-Z: All devices on the bus are High-Z. The voltage level on the bus is undefined as the bus is floating. • ODT: At least one device on the bus is ODT, and all others are High-Z. The voltage level on the bus is nominally V DDQ. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 18 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Ball Assignments Ball Assignments Figure 1: 78-Ball x4, x8 Ball Assignments 1 2 3 VDD VSSQ NF, NF/ TDQS_c 4 5 6 7 8 9 NF, NF/DM_n/ DBI_n/TDQS_t VSSQ VSS A A B B VPP VDDQ DQS_c DQ1 VDDQ ZQ C C VDDQ DQ0 DQS_t VDD VSS VDDQ VSSQ DQ4/NC DQ2 DQ3 DQ5/NC VSSQ VSS VDDQ DQ6/NC DQ7/NC VDDQ VSS D D E E F F C2/ODT1 ODT VDD CK_c CK_t VDD G G C0/CKE1 VSS CKE C1/CS1_n RFU/TEN CS_n H H VDD CAS_n/ A15 WE_n/A14ACT_n RAS_n/A16 VSS J J VREFCA BG0 A10/AP A12/BC_n BG1 VDD K K VSS BA0 A4 A3 BA1 VSS RESET_n A6 A0 A1 A5 ALERT_n VDD A8 A2 A9 A7 VPP L L M M N N VSS Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN A11 PAR A17/NC A13 VDD 1. See Ball Descriptions. 2. A comma “,” separates the configuration; a slash “/” defines a selectable function. For example: Ball A7 = NF, NF/DM_n/DBI_n/TDQS_t where NF applies to the x4 configuration only. NF/DM_n/DBI_n/TDQS_t applies to the x8 configuration only and is selectable between NF, DM_n, DBI_n, or TDQS_t via MRS. 3. Address bits (including bank groups) are density- and configuration-dependent (see Addressing). 4. G9 may be RFU and not assigned as TEN on some die revisions as TEN is not required on 4Gb x4 and x8 offerings. 19 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Ball Assignments Figure 2: 96-Ball x16 Ball Assignments 1 2 3 4 5 6 7 8 9 A A VDDQ VSSQ DQ8 UDQS_c VSSQ VDDQ VPP VSS VDD UDQS_t DQ9 VDD B B C C VDDQ DQ12 DQ11 DQ10 DQ13 VSSQ D D VDD VSSQ VSS NF/UDM_n/ UDBI_n DQ14 DQ15 VSSQ NF/LDM_n/ LDBI_n VSSQ VDDQ E E VSSQ VSS F F VSSQ VDDQ DQ1 LDQS_c VDDQ ZQ G G VDDQ DQ0 VDD LDQS_t VSS VDDQ H H VSSQ DQ4 DQ2 DQ3 DQ5 VSSQ VDD VDDQ DQ6 DQ7 VDDQ VDD J J K K VSS CKE CK_t ODT CK_c VSS L L VDD WE_n/A14 ACT_n CS_n RAS_n/A16 VDD M M VREFCA BG0 A12/BC_n CAS-n/A15 VSS A10/AP N N VSS BA0 A4 A3 BA1 TEN A5 ALERT_n P P RESET_n A6 A0 A1 R R VDD A8 A2 A9 A7 VPP VSS A11 PAR NC A13 VDD T Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN T 1. See Ball Descriptions. 2. A slash “/” defines a selectable function. For example: Ball E7 = NF/LDM_n. If data mask is enabled via the MRS, ball E7 = LDM_n. If data mask is disabled in the MRS, E7 = NF (no function). 3. Address bits (including bank groups) are density- and configuration-dependent (see Addressing). 20 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Ball Descriptions Ball Descriptions The pin description table below is a comprehensive list of all possible pins for DDR4 devices. All pins listed may not be supported on the device defined in this data sheet. See the Ball Assignments section to review all pins used on this device. Table 3: Ball Descriptions Symbol Type Description A[17:0] Input Address inputs: Provide the row address for ACTIVATE commands and the column address for READ/WRITE commands to select one location out of the memory array in the respective bank. (A10/AP, A12/BC_n, WE_n/A14, CAS_n/A15, RAS_n/A16 have additional functions, see individual entries in this table.) The address inputs also provide the op-code during the MODE REGISTER SET command. A16 is used on some 8Gb and 16Gb parts, and A17 is only used on some 16Gb parts. A10/AP Input Auto precharge: A10 is sampled during READ and WRITE commands to determine whether auto precharge should be performed to the accessed bank after a READ or WRITE operation. (HIGH = auto precharge; LOW = no auto precharge.) A10 is sampled during a PRECHARGE command to determine whether the PRECHARGE applies to one bank (A10 LOW) or all banks (A10 HIGH). If only one bank is to be precharged, the bank is selected by the bank group and bank addresses. A12/BC_n Input Burst chop: A12/BC_n is sampled during READ and WRITE commands to determine if burst chop (on-the-fly) will be performed. (HIGH = no burst chop; LOW = burst chopped). See the Command Truth Table. ACT_n Input Command input: ACT_n indicates an ACTIVATE command. When ACT_n (along with CS_n) is LOW, the input pins RAS_n/A16, CAS_n/A15, and WE_n/A14 are treated as row address inputs for the ACTIVATE command. When ACT_n is HIGH (along with CS_n LOW), the input pins RAS_n/ A16, CAS_n/A15, and WE_n/A14 are treated as normal commands that use the RAS_n, CAS_n, and WE_n signals. See the Command Truth Table. BA[1:0] Input Bank address inputs: Define the bank (within a bank group) to which an ACTIVATE, READ, WRITE, or PRECHARGE command is being applied. Also determines which mode register is to be accessed during a MODE REGISTER SET command. BG[1:0] Input Bank group address inputs: Define the bank group to which a REFRESH, ACTIVATE, READ, WRITE, or PRECHARGE command is being applied. Also determines which mode register is to be accessed during a MODE REGISTER SET command. BG[1:0] are used in the x4 and x8 configurations. BG1 is not used in the x16 configuration. C0/CKE1, C1/CS1_n, C2/ODT1 Input Stack address inputs: These inputs are used only when devices are stacked; that is, they are used in 2H, 4H, and 8H stacks for x4 and x8 configurations (these pins are not used in the x16 configuration). DDR4 will support a traditional DDP package, which uses these three signals for control of the second die (CS1_n, CKE1, ODT1). DDR4 is not expected to support a traditional QDP package. For all other stack configurations, such as a 4H or 8H, it is assumed to be a single-load (master/slave) type of configuration where C0, C1, and C2 are used as chip ID selects in conjunction with a single CS_n, CKE, and ODT signal. CK_t, CK_c Input Clock: Differential clock inputs. All address, command, and control input signals are sampled on the crossing of the positive edge of CK_t and the negative edge of CK_c. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 21 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Ball Descriptions Table 3: Ball Descriptions (Continued) Symbol Type Description CKE Input Clock enable: CKE HIGH activates and CKE LOW deactivates the internal clock signals, device input buffers, and output drivers. Taking CKE LOW provides PRECHARGE POWER-DOWN and SELF REFRESH operations (all banks idle), or active power-down (row active in any bank). CKE is asynchronous for self refresh exit. After VREFCA has become stable during the power-on and initialization sequence, it must be maintained during all operations (including SELF REFRESH). CKE must be maintained HIGH throughout read and write accesses. Input buffers (excluding CK_t, CK_c, ODT, RESET_n, and CKE) are disabled during power-down. Input buffers (excluding CKE and RESET_n) are disabled during self refresh. CS_n Input Chip select: All commands are masked when CS_n is registered HIGH. CS_n provides for external rank selection on systems with multiple ranks. CS_n is considered part of the command code. DM_n, UDM_n LDM_n Input Input data mask: DM_n is an input mask signal for write data. Input data is masked when DM is sampled LOW coincident with that input data during a write access. DM is sampled on both edges of DQS. DM is not supported on x4 configurations. The UDM_n and LDM_n pins are used in the x16 configuration: UDM_n is associated with DQ[15:8]; LDM_n is associated with DQ[7:0]. The DM, DBI, and TDQS functions are enabled by mode register settings. See the Data Mask section. ODT Input On-die termination: ODT (registered HIGH) enables termination resistance internal to the DDR4 SDRAM. When enabled, ODT (RTT) is applied only to each DQ, DQS_t, DQS_c, DM_n/DBI_n/TDQS_t, and TDQS_c signal for the x4 and x8 configurations (when the TDQS function is enabled via mode register). For the x16 configuration, RTT is applied to each DQ, DQSU_t, DQSU_c, DQSL_t, DQSL_c, UDM_n, and LDM_n signal. The ODT pin will be ignored if the mode registers are programmed to disable RTT. PAR Input Parity for command and address: This function can be enabled or disabled via the mode register. When enabled, the parity signal covers all command and address inputs, including ACT_n, RAS_n/A16, CAS_n/A15, WE_n/A14, A[17:0], A10/AP, A12/BC_n, BA[1:0], and BG[1:0] with C0, C1, and C2 on 3DS only devices. Control pins NOT covered by the parity signal are CS_n, CKE, and ODT. Unused address pins that are density- and configuration-specific should be treated internally as 0s by the DRAM parity logic. Command and address inputs will have parity check performed when commands are latched via the rising edge of CK_t and when CS_n is LOW. RAS_n/A16, CAS_n/A15, WE_n/A14 Input Command inputs: RAS_n/A16, CAS_n/A15, and WE_n/A14 (along with CS_n and ACT_n) define the command and/or address being entered. See the ACT_n description in this table. RESET_n Input Active LOW asynchronous reset: Reset is active when RESET_n is LOW, and inactive when RESET_n is HIGH. RESET_n must be HIGH during normal operation. RESET_n is a CMOS rail-to-rail signal with DC HIGH and LOW at 80% and 20% of VDD (960 mV for DC HIGH and 240 mV for DC LOW). TEN Input Connectivity test mode: TEN is active when HIGH and inactive when LOW. TEN must be LOW during normal operation. TEN is a CMOS rail-to-rail signal with DC HIGH and LOW at 80% and 20% of VDD (960mV for DC HIGH and 240mV for DC LOW). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 22 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Ball Descriptions Table 3: Ball Descriptions (Continued) Symbol Type Description DQ I/O Data input/output: Bidirectional data bus. DQ represents DQ[3:0], DQ[7:0], and DQ[15:0] for the x4, x8, and x16 configurations, respectively. If write CRC is enabled via mode register, the write CRC code is added at the end of data burst. Any one or all of DQ0, DQ1, DQ2, and DQ3 may be used to monitor the internal VREF level during test via mode register setting MR[4] A[4] = HIGH, training times change when enabled. During this mode, the RTT value should be set to High-Z. This measurement is for verification purposes and is NOT an external voltage supply pin. DBI_n, UDBI_n, LDBI_n I/O DBI input/output: Data bus inversion. DBI_n is an input/output signal used for data bus inversion in the x8 configuration. UDBI_n and LDBI_n are used in the x16 configuration; UDBI_n is associated with DQ[15:8], and LDBI_n is associated with DQ[7:0]. The DBI feature is not supported on the x4 configuration. DBI can be configured for both READ (output) and WRITE (input) operations depending on the mode register settings. The DM, DBI, and TDQS functions are enabled by mode register settings. See the Data Bus Inversion section. DQS_t, DQS_c, DQSU_t, DQSU_c, DQSL_t, DQSL_c I/O Data strobe: Output with READ data, input with WRITE data. Edge-aligned with READ data, centered-aligned with WRITE data. For the x16, DQSL corresponds to the data on DQ[7:0]; DQSU corresponds to the data on DQ[15:8]. For the x4 and x8 configurations, DQS corresponds to the data on DQ[3:0] and DQ[7:0], respectively. DDR4 SDRAM supports a differential data strobe only and does not support a single-ended data strobe. ALERT_n Output Alert output: This signal allows the DRAM to indicate to the system's memory controller that a specific alert or event has occurred. Alerts will include the command/ address parity error and the CRC data error when either of these functions is enabled in the mode register. TDQS_t, TDQS_c Output Termination data strobe: TDQS_t and TDQS_c are used by x8 DRAMs only. When enabled via the mode register, the DRAM will enable the same RTT termination resistance on TDQS_t and TDQS_c that is applied to DQS_t and DQS_c. When the TDQS function is disabled via the mode register, the DM/TDQS_t pin will provide the DATA MASK (DM) function, and the TDQS_c pin is not used. The TDQS function must be disabled in the mode register for both the x4 and x16 configurations. The DM function is supported only in x8 and x16 configurations. VDD Supply Power supply: 1.2V ±0.060V. VDDQ Supply DQ power supply: 1.2V ±0.060V. VPP Supply DRAM activating power supply: 2.5V –0.125V/+0.250V. VREFCA Supply Reference voltage for control, command, and address pins. VSS Supply Ground. VSSQ Supply DQ ground. ZQ Reference RFU – Reserved for future use. NC – No connect: No internal electrical connection is present. NF – No function: May have internal connection present but has no function. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Reference ball for ZQ calibration: This ball is tied to an external 240Ω resistor (RZQ), which is tied to VSSQ. 23 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Package Dimensions Package Dimensions Figure 3: 78-Ball FBGA – x4, x8 "HX" 0.155 Seating plane 1.8 CTR Nonconductive overmold 78X Ø0.45 Dimensions apply to solder balls post-reflow on Ø0.35 SMD ball pads. A 0.12 A Ball A1 ID 9 8 7 Ball A1 ID 3 2 1 A B C D E F G H 11.5 ±0.1 9.6 CTR J K L M N 0.8 TYP 0.8 TYP 1.1 ±0.1 6.4 CTR 0.25 MIN 9 ±0.1 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. All dimensions are in millimeters. 2. Solder ball material: SAC305 (Pb-free 96.5% Sn, 3% Ag, 0.5% Cu). 24 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Package Dimensions Figure 4: 78-Ball FBGA – x4, x8 "RH" 0.155 Seating plane A 78X Ø0.45 Dimensions apply to solder balls postreflow on Ø0.35 SMD ball pads. 0.12 A 1.8 CTR Nonconductive overmold Ball A1 ID (covered by SR) 9 8 7 3 2 Ball A1 ID 1 A B C D E F 10.5 ±0.1 G 9.6 CTR H J K L M N 0.8 TYP 0.8 TYP 1.1 ±0.1 6.4 CTR 0.25 MIN 9 ±0.1 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. All dimensions are in millimeters. 2. Solder ball material: SAC305 (Pb-free 96.5% Sn, 3% Ag, 0.5% Cu). 25 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Package Dimensions Figure 5: 96-Ball FBGA – x16 "HA" 0.155 Seating plane 1.8 CTR Nonconductive overmold 96X Ø0.45 Dimensions apply to solder balls post-reflow on Ø0.35 SMD ball pads. 9 8 7 3 A 2 0.12 A Ball A1 Index (covered by SR) 1 Ball A1 Index A B C D E F G H 12 CTR J 14 ±0.1 K L M N P R 0.8 TYP T 0.8 TYP 1.1 ±0.1 6.4 CTR 0.25 MIN 9 ±0.1 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. All dimensions are in millimeters. 2. Solder ball material: SAC305 (Pb-free 96.5% Sn, 3% Ag, 0.5% Cu). 26 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Package Dimensions Figure 6: 96-Ball FBGA – x16 "GE" 0.155 Seating plane A 0.12 A 1.8 CTR Nonconductive overmold 96X Ø0.47 Dimensions apply to solder balls postreflow on Ø0.42 SMD ball pads. Ball A1 ID (covered by SR) 9 8 7 Ball A1 ID 3 2 1 A B C D E F G H J K L M N P R T 14 ±0.1 12 CTR 0.8 TYP 1.1 ±0.1 0.8 TYP 6.4 CTR 0.29 MIN 9 ±0.1 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. All dimensions are in millimeters. 2. Solder ball material: SAC305 (Pb-free 96.5% Sn, 3% Ag, 0.5% Cu). 27 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM State Diagram State Diagram This simplified state diagram provides an overview of the possible state transitions and the commands to control them. Situations involving more than one bank, the enabling or disabling of on-die termination, and some other events are not captured in full detail. Figure 7: Simplified State Diagram IVREFDQ, RTT, and so on MPSM From any state RESET SRX* = SRX with NOP SRX* CKE_L MRS Power applied Power-On RESET MRS SRX* Reset procedure MRS, MPR, write leveling, VREFDQ training PDA mode Initialization TEN = 1 MRS MRS ZQCL SRX MRS SRE MRS Connectivity test TEN = 0 ZQ calibration Self refresh ZQCL,ZQCS REF Idle Refreshing RESET PDE ACT CKE_L CKE_L PDX Active powerdown Precharge powerdown Activating PDX PDE Bank active WRITE WRITE READ WRITE A READ Writing READ READ A WRITE Reading READ A WRITE A WRITE A READ A PRE, PREA Writing PRE, PREA PRE, PREA Precharging Reading Automatic sequence Command sequence PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 28 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM State Diagram Table 4: State Diagram Command Definitions Command Description ACT Active MPR Multipurpose register MRS Mode register set PDE Enter power-down PDX Exit power-down PRE Precharge PREA Precharge all READ RD, RDS4, RDS8 READ A RDA, RDAS4, RDAS8 REF Refresh, fine granularity refresh RESET Start reset procedure SRE Self refresh entry SRX Self refresh exit TEN Boundary scan mode enable WRITE WR, WRS4, WRS8 with/without CRC WRITE A WRA, WRAS4, WRAS8 with/without CRC ZQCL ZQ calibration long ZQCS ZQ calibration short Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. See the Command Truth Table for more details. 29 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Functional Description Functional Description The DDR4 SDRAM is a high-speed dynamic random-access memory internally configured as sixteen banks (4 bank groups with 4 banks for each bank group) for x4/x8 devices, and as eight banks for each bank group (2 bank groups with 4 banks each) for x16 devices. The device uses double data rate (DDR) architecture to achieve high-speed operation. DDR4 architecture is essentially an 8n-prefetch architecture with an interface designed to transfer two data words per clock cycle at the I/O pins. A single read or write access for a device module effectively consists of a single 8n-bit-wide, four-clockcycle-data transfer at the internal DRAM core and eight corresponding n-bit-wide, onehalf-clock-cycle data transfers at the I/O pins. Read and write accesses to the device are burst-oriented. Accesses start at a selected location and continue for a burst length of eight or a chopped burst of four in a programmed sequence. Operation begins with the registration of an ACTIVE command, which is then followed by a READ or WRITE command. The address bits registered coincident with the ACTIVE command are used to select the bank and row to be accessed (BG[1:0] select the bank group for x4/x8, and BG0 selects the bank group for x16; BA[1:0] select the bank, and A[17:0] select the row. See the Addressing section for more details). The address bits registered coincident with the READ or WRITE command are used to select the starting column location for the burst operation, determine if the auto PRECHARGE command is to be issued (via A10), and select BC4 or BL8 mode on-the-fly (OTF) (via A12) if enabled in the mode register. Prior to normal operation, the device must be powered up and initialized in a predefined manner. The following sections provide detailed information covering device reset and initialization, register definition, command descriptions, and device operation. NOTE: The use of the NOP command is allowed only when exiting maximum power saving mode or when entering gear-down mode. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 30 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM RESET and Initialization Procedure RESET and Initialization Procedure To ensure proper device function, the power-up and reset initialization default values for the following mode register (MR) settings are defined as: • • • • • Gear-down mode (MR3 A[3]): 0 = 1/2 rate Per-DRAM addressability (MR3 A[4]): 0 = disable Maximum power-saving mode (MR4 A[1]): 0 = disable CS to command/address latency (MR4 A[8:6]): 000 = disable CA parity latency mode (MR5 A[2:0]): 000 = disable Power-Up and Initialization Sequence The following sequence is required for power-up and initialization: 1. Apply power (RESET_n and TEN should be maintained below 0.2 × V DD while supplies ramp up; all other inputs may be undefined). When supplies have ramped to a valid stable level, RESET_n must be maintained below 0.2 × V DD for a minimum of tPW_RESET_L and TEN must be maintained below 0.2 × V DD for a minimum of 700μs. CKE is pulled LOW anytime before RESET_n is de-asserted (minimum time of 10ns). The power voltage ramp time between 300mV to V DD,min must be no greater than 200ms, and during the ramp, V DD must be greater than or equal to VDDQ and (VDD - V DDQ) < 0.3V. V PP must ramp at the same time or before V DD, and VPP must be equal to or higher than V DD at all times. After V DD has ramped and reached the stable level, the initialization sequence must be started within 64ms. During power-up, either of the following conditions may exist and must be met: • Condition A: – Apply V PP without any slope reversal before or at the same time as V DD and VDDQ. – VDD and V DDQ are driven from a single-power converter output and apply VDD/VDDQ without any slope reversal before or at the same time as V TT and VREFCA. – The voltage levels on all balls other than V DD, V DDQ, V SS, and V SSQ must be less than or equal to V DDQ and V DD on one side and must be greater than or equal to V SSQ and V SS on the other side. – VTT is limited to 0.76V MAX when the power ramp is complete. – VREFCA tracks V DD/2. • Condition B: – Apply V PP without any slope reversal before or at the same time as V DD. – Apply V DD without any slope reversal before or at the same time as V DDQ. – Apply V DDQ without any slope reversal before or at the same time as V TT and VREFCA. – The voltage levels on all pins other than V PP, V DD, V DDQ, V SS, and V SSQ must be less than or equal to V DDQ and V DD on one side and must be larger than or equal to V SSQ and V SS on the other side. 2. After RESET_n is de-asserted, wait for another 500μs until CKE becomes active. During this time, the device will start internal state initialization; this will be done independently of external clocks. A reasonable attempt was made in the design to power up with the following default MR settings: gear-down mode (MR3 A[3]): 0 = 1/2 rate; per-DRAM addressability (MR3 A[4]): 0 = disable; maximum power-down PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 31 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM RESET and Initialization Procedure 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. (MR4 A[1]): 0 = disable; CS to command/address latency (MR4 A[8:6]): 000 = disable; CA parity latency mode (MR5 A[2:0]): 000 = disable. However, it should be assumed that at power up the MR settings are undefined and should be programmed as shown below. Clocks (CK_t, CK_c) need to be started and stabilized for at least 10ns or 5 tCK (whichever is larger) before CKE goes active. Because CKE is a synchronous signal, the corresponding setup time to clock (tIS) must be met. Also, a DESELECT command must be registered (with tIS setup time to clock) at clock edge Td. After the CKE is registered HIGH after RESET, CKE needs to be continuously registered HIGH until the initialization sequence is finished, including expiration of tDLLK and tZQINIT. The device keeps its ODT in High-Z state as long as RESET_n is asserted. Further, the SDRAM keeps its ODT in High-Z state after RESET_n de-assertion until CKE is registered HIGH. The ODT input signal may be in an undefined state until tIS before CKE is registered HIGH. When CKE is registered HIGH, the ODT input signal may be statically held either LOW or HIGH. If RTT(NOM) is to be enabled in MR1, the ODT input signal must be statically held LOW. In all cases, the ODT input signal remains static until the power-up initialization sequence is finished, including the expiration of tDLLK and tZQINIT. After CKE is registered HIGH, wait a minimum of RESET CKE EXIT time, tXPR, before issuing the first MRS command to load mode register (tXPR = MAX (tXS; 5 × tCK). Issue MRS command to load MR3 with all application settings, wait tMRD. Issue MRS command to load MR6 with all application settings, wait tMRD. Issue MRS command to load MR5 with all application settings, wait tMRD. Issue MRS command to load MR4 with all application settings, wait tMRD. Issue MRS command to load MR2 with all application settings, wait tMRD. Issue MRS command to load MR1 with all application settings, wait tMRD. Issue MRS command to load MR0 with all application settings, wait tMOD. Issue a ZQCL command to start ZQ calibration. Wait for tDLLK and tZQINIT to complete. The device will be ready for normal operation. A stable valid V DD level is a set DC level (0 Hz to 20 MHz) and must be no less than VDD,min and no greater than V DD,max. If the set DC level is altered anytime after initialization, the DLL reset and calibrations must be performed again after the new set DC level is stable. AC noise of ±60mV (greater than 20 MHz) is allowed on V DD provided the noise doesn't alter V DD to less than V DD,min or greater than V DD,max. A stable valid V DDQ level is a set DC level (0 Hz to 20 MHz) and must be no less than VDDQ,min and no greater than V DDQ,max. If the set DC level is altered anytime after initialization, the DLL reset and calibrations must be performed again after the new set DC level is stable. AC noise of ±60mV (greater than 20 MHz) is allowed on V DDQ provided the noise doesn't alter V DDQ to less than V DDQ,min or greater than V DDQ,max. A stable valid V PP level is a set DC level (0 Hz to 20 MHz) and must be no less than VPP,min and no greater than V PP,max. If the set DC level is altered anytime after initialization, the DLL reset and calibrations must be performed again after the new set DC level is stable. AC noise of ±120mV (greater than 20 MHz) is allowed on V PP provided the noise doesn't alter V PP to less than V PP,min or greater than V PP,max. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 32 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM RESET and Initialization Procedure Figure 8: RESET and Initialization Sequence at Power-On Ramping Ta Tb Tc Td Te Th Tg Tf Ti Tj Tk CK_t, CK_c tCKSRX VPP VDD, VDDQ tPW_RESET_L T = 500μs RESET_n T (MIN) = 10ns tIS Valid CKE tDLLK tIS Command Note 1 BG, BA tXPR tMRD tMRD tMRD tZQinit tMOD MRS MRS MRS MRS MRx MRx MRx MRx ZQCL Note 1 Valid tIS tIS Static LOW in case RTT(NOM) is enabled at time Tg, otherwise static HIGH or LOW ODT Valid Valid RTT Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. From time point Td until Tk, a DES command must be applied between MRS and ZQCL commands. 2. MRS commands must be issued to all mode registers that have defined settings. 3. In general, there is no specific sequence for setting the MRS locations (except for dependent or co-related features, such as ENABLE DLL in MR1 prior to RESET DLL in MR0, for example). 4. TEN is not shown; however, it is assumed to be held LOW. 33 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM RESET and Initialization Procedure RESET Initialization with Stable Power Sequence The following sequence is required for RESET at no power interruption initialization: 1. Assert RESET_n below 0.2 × V DD any time reset is needed (all other inputs may be undefined). RESET must be maintained for a minimum of 100ns. CKE is pulled LOW before RESET_n is de-asserted (minimum time 10ns). 2. Follow Steps 2 to 7 in the Reset and Initialization Sequence at Power-on Ramping procedure. When the reset sequence is complete, all counters except the refresh counters have been reset and the device is ready for normal operation. Figure 9: RESET Procedure at Power Stable Condition Ta Tc Tb Td Te Th Tg Tf Ti Tj Tk CK_t, CK_c tCKSRX VPP VDD , VDDQ tPW_RESET_S T = 500μs RESET_n T (MIN) = 10ns tIS Valid CKE tDLLK tIS Command Note 1 BG, BA tXPR tMRD tMRD tMRD tMOD MRS MRS MRS MRS MRx MRx MRx MRx tZQinit ZQCL Note 1 Valid tIS tIS Static LOW in case RTT(NOM) is enabled at time Tg, otherwise static HIGH or LOW ODT Valid Valid RTT Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. From time point Td until Tk, a DES command must be applied between MRS and ZQCL commands. 2. MRS commands must be issued to all mode registers that have defined settings. 3. In general, there is no specific sequence for setting the MRS locations (except for dependent or co-related features, such as ENABLE DLL in MR1 prior to RESET DLL in MR0, for example). 4. TEN is not shown; however, it is assumed to be held LOW. 34 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Programming Mode Registers Uncontrolled Power-Down Sequence In the event of an uncontrolled ramping down of V PP supply, V PP is allowed to be less than V DD provided the following conditions are met: • Condition A: V PP and V DD/VDDQ are ramping down (as part of turning off) from normal operating levels. • Condition B: The amount that V PP may be less than V DD/VDDQ is less than or equal to 500mV. • Condition C: The time V PP may be less than V DD is ≤10ms per occurrence with a total accumulated time in this state ≤100ms. • Condition D: The time V PP may be less than 2.0V and above V SS while turning off is ≤15ms per occurrence with a total accumulated time in this state ≤150ms. Programming Mode Registers For application flexibility, various functions, features, and modes are programmable in seven mode registers (MRn) provided by the device as user defined variables that must be programmed via a MODE REGISTER SET (MRS) command. Because the default values of the mode registers are not defined, contents of mode registers must be fully initialized and/or re-initialized; that is, they must be written after power-up and/or reset for proper operation. The contents of the mode registers can be altered by re-executing the MRS command during normal operation. When programming the mode registers, even if the user chooses to modify only a sub-set of the MRS fields, all address fields within the accessed mode register must be redefined when the MRS command is issued. MRS and DLL RESET commands do not affect array contents, which means these commands can be executed any time after power-up without affecting the array contents. The MRS command cycle time, tMRD, is required to complete the WRITE operation to the mode register and is the minimum time required between the two MRS commands shown in the tMRD Timing figure. Some of the mode register settings affect address/command/control input functionality. In these cases, the next MRS command can be allowed when the function being updated by the current MRS command is completed. These MRS commands don’t apply tMRD timing to the next MRS command; however, the input cases have unique MR setting procedures, so refer to individual function descriptions: • • • • • • • • Gear-down mode Per-DRAM addressability Maximum power saving mode CS to command/address latency CA parity latency mode VREFDQ training value VREFDQ training mode VREFDQ training range Some mode register settings may not be supported because they are not required by certain speed bins. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 35 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Programming Mode Registers Figure 10: tMRD Timing T0 T1 T2 Ta0 Ta1 Tb0 Tb1 Tb2 Tc0 Tc1 Tc2 Command Valid Valid Valid MRS2 DES DES DES DES DES MRS2 Valid Address Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid CK_c CK_t CKE tMRD Updating settings Old settings Settings Time Break Don’t Care 1. This timing diagram depicts CA parity mode “disabled” case. 2. tMRD applies to all MRS commands with the following exceptions: Gear-down mode CA parity mode CAL mode Per-DRAM addressability mode VREFDQ training value, VREFDQ training mode, and VREFDQ training range Notes: The MRS command to nonMRS command delay, tMOD, is required for the DRAM to update features, except DLL RESET. tMOD is the minimum time required from an MRS command to a nonMRS command, excluding DES, as shown in the tMOD Timing figure. Figure 11: tMOD Timing T0 T1 T2 Ta0 Ta1 Ta2 Ta3 Ta4 Tb0 Tb1 Tb2 Command Valid Valid Valid MRS2 DES DES DES DES DES Valid Valid Address Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid CK_c CK_t CKE t Settings MOD Updating settings Old settings New settings Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. This timing diagram depicts CA parity mode “disabled” case. 2. tMOD applies to all MRS commands with the following exceptions: DLL enable, Gear-down mode VREFDQ training value, internal VREF training monitor, VREFDQ training mode, and VREFDQ training range Maximum power savings mode , Per-DRAM addressability mode, and CA parity mode 36 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Programming Mode Registers The mode register contents can be changed using the same command and timing requirements during normal operation as long as the device is in idle state; that is, all banks are in the precharged state with tRP satisfied, all data bursts are completed, and CKE is HIGH prior to writing into the mode register. If the RTT(NOM) feature is enabled in the mode register prior to and/or after an MRS command, the ODT signal must continuously be registered LOW, ensuring RTT is in an off state prior to the MRS command. The ODT signal may be registered HIGH after tMOD has expired. If the RTT(NOM) feature is disabled in the mode register prior to and after an MRS command, the ODT signal can be registered either LOW or HIGH before, during, and after the MRS command. The mode registers are divided into various fields depending on functionality and modes. In some mode register setting cases, function updating takes longer than tMOD. This type of MRS does not apply tMOD timing to the next valid command, excluding DES. These MRS command input cases have unique MR setting procedures, so refer to individual function descriptions. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 37 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 0 Mode Register 0 Mode register 0 (MR0) controls various device operating modes as shown in the following register definition table. Not all settings listed may be available on a die; only settings required for speed bin support are available. MR0 is written by issuing the MRS command while controlling the states of the BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the following MR0 Register Definition table. Table 5: Address Pin Mapping Address BG1 BG0 BA1 BA0 A17 RAS CAS WE A13 A12 A11 A10 A9 bus _n _n _n Mode register 21 20 19 18 Note: 17 – – – 13 12 11 10 9 A8 A7 A6 A5 A4 A3 A2 A1 A0 8 7 6 5 4 3 2 1 0 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET command. Table 6: MR0 Register Definition Mode Register 21 20:18 17 13,11:9 Description RFU 0 = Must be programmed to 0 1 = Reserved MR select 000 = MR0 001 = MR1 010 = MR2 011 = MR3 100 = MR4 101 = MR5 110 = MR6 111 = DNU N/A on 4Gb and 8Gb, RFU 0 = Must be programmed to 0 1 = Reserved WR (WRITE recovery)/RTP (READ-to-PRECHARGE) 0000 = 10 / 5 clocks1 0001 = 12 / 6 clocks 0010 = 14 / 7 clocks1 0011 = 16 / 8 / clocks 0100 = 18 / 9 clocks1 0101 = 20 /10 clocks 0110 = 24 / 12 clocks 0111 = 22 / 11 clocks1 1000 = 26 / 13 clocks1 1001 through 1111 = Reserved PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 38 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 0 Table 6: MR0 Register Definition (Continued) Mode Register Description 8 DLL reset 0 = No 1 = Yes 7 Test mode (TM) – Manufacturer use only 0 = Normal operating mode, must be programmed to 0 12, 6:4, 2 3 1:0 CAS latency (CL) – Delay in clock cycles from the internal READ command to first data-out 00000 = 9 clocks1 00001 = 10 clocks 00010 = 11 clocks1 00011 = 12 clocks 00100 = 13 clocks1 00101 = 14 clocks 00110 = 15 clocks1 00111 = 16 clocks 01000 = 18 clocks 01001 = 20 clocks 01010 = 22 clocks 01011 = 24 clocks 01100 = 23 clocks1 01101 = 17 clocks1 01110 = 19 clocks1 01111 = 21 clocks 1 10000 = 25 clocks (3DS use only) 10001 = 26 clocks 10010 = 27 clocks (3DS use only) 10011 = 28 clocks 10100 = 29 clocks1 10101 = 30 clocks 10110 = 31 clocks1 10111 = 32 clocks Burst type (BT) – Data burst ordering within a READ or WRITE burst access 0 = Nibble sequential 1 = Interleave Burst length (BL) – Data burst size associated with each read or write access 00 = BL8 (fixed) 01 = BC4 or BL8 (on-the-fly) 10 = BC4 (fixed) 11 = Reserved Note: 1. Not allowed when 1/4 rate gear-down mode is enabled. Burst Length, Type, and Order Accesses within a given burst may be programmed to sequential or interleaved order. The ordering of accesses within a burst is determined by the burst length, burst type, and the starting column address as shown in the following table. Burst length options PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 39 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 0 include fixed BC4, fixed BL8, and on-the-fly (OTF), which allows BC4 or BL8 to be selected coincidentally with the registration of a READ or WRITE command via A12/BC_n. Table 7: Burst Type and Burst Order Note 1 applies to the entire table Starting Column Address Burst READ/ (A[2, 1, 0]) Length WRITE BC4 READ WRITE BL8 READ WRITE Notes: Burst Type = Sequential (Decimal) Burst Type = Interleaved (Decimal) Notes 000 0, 1, 2, 3, T, T, T, T 0, 1, 2, 3, T, T, T, T 2, 3 001 1, 2, 3, 0, T, T, T, T 1, 0, 3, 2, T, T, T, T 2, 3 010 2, 3, 0, 1, T, T, T, T 2, 3, 0, 1, T, T, T, T 2, 3 011 3, 0, 1, 2, T, T, T, T 3, 2, 1, 0, T, T, T, T 2, 3 100 4, 5, 6, 7, T, T, T, T 4, 5, 6, 7, T, T, T, T 2, 3 101 5, 6, 7, 4, T, T, T, T 5, 4, 7, 6, T, T, T, T 2, 3 110 6, 7, 4, 5, T, T, T, T 6, 7, 4, 5, T, T, T, T 2, 3 111 7, 4, 5, 6, T, T, T, T 7, 6, 5, 4, T, T, T, T 2, 3 0, V, V 0, 1, 2, 3, X, X, X, X 0, 1, 2, 3, X, X, X, X 2, 3 1, V, V 4, 5, 6, 7, X, X, X, X 4, 5, 6, 7, X, X, X, X 2, 3 000 0, 1, 2, 3, 4, 5, 6, 7 0, 1, 2, 3, 4, 5, 6, 7 001 1, 2, 3, 0, 5, 6, 7, 4 1, 0, 3, 2, 5, 4, 7, 6 010 2, 3, 0, 1, 6, 7, 4, 5 2, 3, 0, 1, 6, 7, 4, 5 011 3, 0, 1, 2, 7, 4, 5, 6 3, 2, 1, 0, 7, 6, 5, 4 100 4, 5, 6, 7, 0, 1, 2, 3 4, 5, 6, 7, 0, 1, 2, 3 101 5, 6, 7, 4, 1, 2, 3, 0 5, 4, 7, 6, 1, 0, 3, 2 110 6, 7, 4, 5, 2, 3, 0, 1 6, 7, 4, 5, 2, 3, 0, 1 111 7, 4, 5, 6, 3, 0, 1, 2 7, 6, 5, 4, 3, 2, 1, 0 V, V, V 0, 1, 2, 3, 4, 5, 6, 7 0, 1, 2, 3, 4, 5, 6, 7 3 1. 0...7 bit number is the value of CA[2:0] that causes this bit to be the first read during a burst. 2. When setting burst length to BC4 (fixed) in MR0, the internal WRITE operation starts two clock cycles earlier than for the BL8 mode, meaning the starting point for tWR and tWTR will be pulled in by two clocks. When setting burst length to OTF in MR0, the internal WRITE operation starts at the same time as a BL8 (even if BC4 was selected during column time using A12/BC4_n) meaning that if the OTF MR0 setting is used, the starting point for tWR and tWTR will not be pulled in by two clocks as described in the BC4 (fixed) case. 3. T = Output driver for data and strobes are in High-Z. V = Valid logic level (0 or 1), but respective buffer input ignores level on input pins. X = “Don’t Care.” CAS Latency The CAS latency (CL) setting is defined in the MR0 Register Definition table. CAS latency is the delay, in clock cycles, between the internal READ command and the availability of the first bit of output data. The device does not support half-clock latencies. The PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 40 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 0 overall read latency (RL) is defined as additive latency (AL) + CAS latency (CL): RL = AL + CL. Test Mode The normal operating mode is selected by MR0[7] and all other bits set to the desired values shown in the MR0 Register Definition table. Programming MR0[7] to a value of 1 places the device into a DRAM manufacturer-defined test mode to be used only by the manufacturer, not by the end user. No operations or functionality is specified if MR0[7] = 1. Write Recovery(WR)/READ-to-PRECHARGE The programmed write recovery (WR) value is used for the auto precharge feature along with tRP to determine tDAL. WR for auto precharge (MIN) in clock cycles is calculated by dividing tWR (in ns) by tCK (in ns) and rounding up to the next integer: WR (MIN) cycles = roundup (tWR[ns]/tCK[ns]). The WR value must be programmed to be equal to or larger than tWR (MIN). When both DM and write CRC are enabled in the mode register, the device calculates CRC before sending the write data into the array; tWR values will change when enabled. If there is a CRC error, the device blocks the WRITE operation and discards the data. Internal READ-to-PRECHARGE (RTP) command delay for auto precharge (MIN) in clock cycles is calculated by dividing tRTP (in ns) by tCK (in ns) and rounding up to the next integer: RTP (MIN) cycles = roundup (tRTP[ns]/tCK[ns]). The RTP value in the mode register must be programmed to be equal to or larger than RTP (MIN). The programmed RTP value is used with tRP to determine the ACT timing to the same bank. DLL RESET The DLL reset bit is self-clearing, meaning that it returns to the value of 0 after the DLL RESET function has been issued. After the DLL is enabled, a subsequent DLL RESET should be applied. Any time the DLL RESET function is used, tDLLK must be met before functions requiring the DLL can be used, such as READ commands or synchronous ODT operations, for example,). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 41 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 1 Mode Register 1 Mode register 1 (MR1) controls various device operating modes as shown in the following register definition table. Not all settings listed may be available on a die; only settings required for speed bin support are available. MR1 is written by issuing the MRS command while controlling the states of the BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the following MR1 Register Definition table. Table 8: Address Pin Mapping Address BG1 BG0 BA1 BA0 A17 RAS CAS WE A13 A12 A11 A10 A9 bus _n _n _n Mode register 21 20 19 18 Note: 17 – – – 13 12 11 10 9 A8 A7 A6 A5 A4 A3 A2 A1 A0 8 7 6 5 4 3 2 1 0 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET command. Table 9: MR1 Register Definition Mode Register 21 20:18 Description RFU 0 = Must be programmed to 0 1 = Reserved MR select 000 = MR0 001 = MR1 010 = MR2 011 = MR3 100 = MR4 101 = MR5 110 = MR6 111 = DNU 17 N/A on 4Gb and 8Gb, RFU 0 = Must be programmed to 0 1 = Reserved 13 RFU 0 = Must be programmed to 0 1 = Reserved 12 Data output disable (Qoff) – Output buffer disable 0 = Enabled (normal operation) 1 = Disabled (both ODI and RTT) 11 Termination data strobe (TDQS) – Additional termination pins (x8 configuration only) 0 = TDQS disabled 1 = TDQS enabled PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 42 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 1 Table 9: MR1 Register Definition (Continued) Mode Register 10, 9, 8 7 Description Nominal ODT (RTT(NOM) – Data bus termination setting 000 = RTT(NOM) disabled 001 = RZQ/4 (60 ohm) 010 = RZQ/2 (120 ohm) 011 = RZQ/6 (40 ohm) 100 = RZQ/1 (240 ohm) 101 = RZQ/5 (48 ohm) 110 = RZQ/3 (80 ohm) 111 = RZQ/7 (34 ohm) Write leveling (WL) – Write leveling mode 0 = Disabled (normal operation) 1 = Enabled (enter WL mode) 6, 5 RFU 0 = Must be programmed to 0 1 = Reserved 4, 3 Additive latency (AL) – Command additive latency setting 00 = 0 (AL disabled) 01 = CL - 11 10 = CL - 2 11 = Reserved 2, 1 Output driver impedance (ODI) – Output driver impedance setting 00 = RZQ/7 (34 ohm) 01 = RZQ/5 (48 ohm) 10 = Reserved (Although not JEDEC-defined and not tested, this setting will provide RZQ/6 or 40 ohm) 11 = Reserved 0 DLL enable – DLL enable feature 0 = DLL disabled 1 = DLL enabled (normal operation) Note: 1. Not allowed when 1/4 rate gear-down mode is enabled. DLL Enable/DLL Disable The DLL must be enabled for normal operation and is required during power-up initialization and upon returning to normal operation after having the DLL disabled. During normal operation (DLL enabled with MR1[0]) the DLL is automatically disabled when entering the SELF REFRESH operation and is automatically re-enabled upon exit of the SELF REFRESH operation. Any time the DLL is enabled and subsequently reset, tDLLK clock cycles must occur before a READ or SYNCHRONOUS ODT command can be issued to allow time for the internal clock to be synchronized with the external clock. Failing to wait for synchronization to occur may result in a violation of the tDQSCK, tAON, or tAOF parameters. During tDLLK, CKE must continuously be registered HIGH. The device does not require DLL for any WRITE operation, except when R TT(WR) is enabled and the DLL is required for proper ODT operation. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 43 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 1 The direct ODT feature is not supported during DLL off mode. The ODT resistors must be disabled by continuously registering the ODT pin LOW and/or by programming the RTT(NOM) bits MR1[9,6,2] = 000 via an MRS command during DLL off mode. The dynamic ODT feature is not supported in DLL off mode; to disable dynamic ODT externally, use the MRS command to set RTT(WR), MR2[10:9] = 00. Output Driver Impedance Control The output driver impedance of the device is selected by MR1[2,1], as shown in the MR1 Register Definition table. ODT RTT(NOM) Values The device is capable of providing three different termination values: RTT(Static), RTT(NOM), and RTT(WR). The nominal termination value, R TT(NOM), is programmed in MR1. A separate value, RTT(WR), may be programmed in MR2 to enable a unique RTT value when ODT is enabled during WRITE operations. The R TT(WR) value can be applied during WRITE commands even when R TT(NOM) is disabled. A third RTT value, RTT(Static), is programed in MR5. RTT(Static) provides a termination value when the ODT signal is LOW. Additive Latency The ADDITIVE LATENCY (AL) operation is supported to make command and data buses efficient for sustainable bandwidths in the device. In this operation, the device allows a READ or WRITE command (either with or without auto precharge) to be issued immediately after the ACTIVATE command. The command is held for the time of AL before it is issued inside the device. READ latency (RL) is controlled by the sum of the AL and CAS latency (CL) register settings. WRITE latency (WL) is controlled by the sum of the AL and CAS WRITE latency (CWL) register settings. Table 10: Additive Latency (AL) Settings A4 A3 AL 0 0 0 (AL disabled) 0 1 CL - 1 1 0 CL - 2 1 1 Reserved Note: 1. AL has a value of CL - 1 or CL - 2 based on the CL values programmed in the MR0 register. Write Leveling For better signal integrity, the device uses fly-by topology for the commands, addresses, control signals, and clocks. Fly-by topology benefits from a reduced number of stubs and their lengths, but it causes flight-time skew between clock and strobe at every DRAM on the DIMM. This makes it difficult for the controller to maintain tDQSS, tDSS, and tDSH specifications. Therefore, the device supports a write leveling feature that allows the controller to compensate for skew. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 44 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 1 Output Disable The device outputs may be enabled/disabled by MR1[12] as shown in the MR1 Register Definition table. When MR1[12] is enabled (MR1[12] = 1) all output pins (such as DQ and DQS) are disconnected from the device, which removes any loading of the output drivers. For example, this feature may be useful when measuring module power. For normal operation, set MR1[12] to 0. Termination Data Strobe Termination data strobe (TDQS) is a feature of the x8 device and provides additional termination resistance outputs that may be useful in some system configurations. Because this function is available only in a x8 configuration, it must be disabled for x4 and x16 configurations. While TDQS is not supported in x4 or x16 configurations, the same termination resistance function that is applied to the TDQS pins is applied to the DQS pins when enabled via the mode register. The TDQS, DBI, and DATA MASK (DM) functions share the same pin. When the TDQS function is enabled via the mode register, the DM and DBI functions are not supported. When the TDQS function is disabled, the DM and DBI functions can be enabled separately. Table 11: TDQS Function Matrix TDQS Data Mask (DM) WRITE DBI READ DBI Disabled Enabled Disabled Enabled or disabled Enabled PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Disabled Enabled Enabled or disabled Disabled Disabled Enabled or disabled Disabled Disabled Disabled 45 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 2 Mode Register 2 Mode register 2 (MR2) controls various device operating modes as shown in the following register definition table. Not all settings listed may be available on a die; only settings required for speed bin support are available. MR2 is written by issuing the MRS command while controlling the states of the BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the following MR2 Register Definition table. Table 12: Address Pin Mapping Address BG1 BG0 BA1 BA0 A17 RAS CAS WE A13 A12 A11 A10 A9 bus _n _n _n Mode register 21 20 19 18 Note: 17 – – – 13 12 11 10 9 A8 A7 A6 A5 A4 A3 A2 A1 A0 8 7 6 5 4 3 2 1 0 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET command. Table 13: MR2 Register Definition Mode Register Description 21 20:18 RFU 0 = Must be programmed to 0 1 = Reserved MR select 000 = MR0 001 = MR1 010 = MR2 011 = MR3 100 = MR4 101 = MR5 110 = MR6 111 = DNU 17 N/A on 4Gb and 8Gb, RFU 0 = Must be programmed to 0 1 = Reserved 13 TRR mode 0 = Disabled 1 = Enabled 12 WRITE data bus CRC 0 = Disabled 1 = Enabled PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 46 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 2 Table 13: MR2 Register Definition (Continued) Mode Register Description 11:9 Dynamic ODT (RTT(WR)) – Data bus termination setting during WRITEs 000 = RTT(WR) disabled (WRITE does not affect RTT value) 001 = RZQ/2 (120 ohm) 010 = RZQ/1 (240 ohm) 011 = High-Z 100 = RZQ/3 (80 ohm) 101 = Reserved 110 = Reserved 111 = Reserved 7:6 Low-power auto self refresh (LPASR) – Mode summary 00 = Manual mode - Normal operating temperature range (TC: 0°C–85°C) 01 = Manual mode - Reduced operating temperature range (TC: 0°C–45°C) 10 = Manual mode - Extended operating temperature range (TC: 0°C–95°C) 11 = ASR mode - Automatically switching among all modes 5:3 CAS WRITE latency (CWL) – Delay in clock cycles from the internal WRITE command to first data-in 1tCK WRITE preamble 000 = 9 (DDR4-1600)1 001 = 10 (DDR4-1866) 010 = 11 (DDR4-2133/1600)1 011 = 12 (DDR4-2400/1866) 100 = 14 (DDR4-2666/2133) 101 = 16 (DDR4-2933,3200/2400) 110 = 18 (DDR4-2666) 111 = 20 (DDR4-2933, 3200) CAS WRITE latency (CWL) – Delay in clock cycles from the internal WRITE command to first data-in 2tCK WRITE preamble 000 = N/A 001 = N/A 010 = N/A 011 = N/A 100 = 14 (DDR4-2400) 101 = 16 (DDR4-2666/2400) 110 = 18 (DDR4-2933, 3200/2666) 111 = 20 (DDR4-2933, 3200) 8, 2 TRR mode - BGn control 00 = BG0 01 = BG1 10 = BG2 11 = BG3 1:0 TRR mode - BAn control 00 = BA0 01 = BA1 10 = BA2 11 = BA3 Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Not allowed when 1/4 rate gear-down mode is enabled. 47 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 2 CAS WRITE Latency CAS WRITE latency (CWL) is defined by MR2[5:3] as shown in the MR2 Register Definition table. CWL is the delay, in clock cycles, between the internal WRITE command and the availability of the first bit of input data. The device does not support any half-clock latencies. The overall WRITE latency (WL) is defined as additive latency (AL) + parity latency (PL) + CAS WRITE latency (CWL): WL = AL +PL + CWL. Low-Power Auto Self Refresh Low-power auto self refresh (LPASR) is supported in the device. Applications requiring SELF REFRESH operation over different temperature ranges can use this feature to optimize the IDD6 current for a given temperature range as specified in the MR2 Register Definition table. Dynamic ODT In certain applications and to further enhance signal integrity on the data bus, it is desirable to change the termination strength of the device without issuing an MRS command. This may be done by configuring the dynamic ODT (R TT(WR)) settings in MR2[11:9]. In write leveling mode, only RTT(NOM) is available. Write Cyclic Redundancy Check Data Bus The write cyclic redundancy check (CRC) data bus feature during writes has been added to the device. When enabled via the mode register, the data transfer size goes from the normal 8-bit (BL8) frame to a larger 10-bit UI frame, and the extra two UIs are used for the CRC information. Target Row Refresh Mode For the device, rows can be accessed a limited number of times within a certain time period before adjacent rows require refresh. The maximum activate count (MAC) is the maximum number of activates that a single row can sustain within a time interval of equal to or less than the maximum activate window (tMAW) before the adjacent rows need to be refreshed regardless of how the activates are distributed over tMAW. The row receiving the excessive activates is the target row (TRn); the two adjacent rows to be refreshed are the victim rows. When the MAC limit is reached on TRn, either the device must receive (roundup of tMAW / tREFI) REFRESH commands (REF) before another row activate is issued, or it needs to be placed into targeted row refresh (TRR) mode. The TRR mode will refresh the rows adjacent to the TRn that encountered the MAC limit. There could be one or two target rows in a bank associated to one victim row. The cumulative value of the activates from two target rows on a victim row should not exceed the MAC value as well. When the temperature controlled refresh (TCR) mode is enabled, tMAW should be adjusted depending on the TCR range as shown in the following table. Using TRR mode is not required, and in some cases has been rendered inoperable, as the device automatically performs TRR Mode in the background. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 48 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 3 Mode Register 3 Mode register 3 (MR3) controls various device operating modes as shown in the following register definition table. Not all settings listed may be available on a die; only settings required for speed bin support are available. MR3 is written by issuing the MRS command while controlling the states of the BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the following MR3 Register Definition table. Table 14: Address Pin Mapping Address BG1 BG0 BA1 BA0 A17 RAS CAS WE A13 A12 A11 A10 A9 bus _n _n _n Mode register 21 20 19 18 Note: 17 – – – 13 12 11 10 9 A8 A7 A6 A5 A4 A3 A2 A1 A0 8 7 6 5 4 3 2 1 0 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET command. Table 15: MR3 Register Definition Mode Register 21 20:18 Description RFU 0 = Must be programmed to 0 1 = Reserved MR select 000 = MR0 001 = MR1 010 = MR2 011 = MR3 100 = MR4 101 = MR5 110 = MR6 111 = DNU 17 N/A on 4Gb and 8Gb, RFU 0 = Must be programmed to 0 1 = Reserved 13 RFU 0 = Must be programmed to 0 1 = Reserved 12:11 Multipurpose register (MPR) – Read format 00 = Serial 01 = Parallel 10 = Staggered 11 = Reserved 10:9 WRITE CMD latency when CRC/DM enabled 00 = 4CK (DDR4-1600) 01 = 5CK (DDR4-1866/2133/2400) 10 = 6CK (DDR4-2666/2933/3200) 11 = Reserved PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 49 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 3 Table 15: MR3 Register Definition (Continued) Mode Register 8:6 Description Fine granularity refresh mode 000 = Normal mode (fixed 1x) 001 = Fixed 2x 010 = Fixed 4x 011 = Reserved 100 = Reserved 101 = On-the-fly 1x/2x 110 = On-the-fly 1x/4x 111 = Reserved 5 Temperature sensor status 0 = Disabled 1 = Enabled 4 Per-DRAM addressability 0 = Normal operation (disabled) 1 = Enable 3 Gear-down mode – Ratio of internal clock to external data rate 0 = [1:1]; (1/2 rate data) 1 = [2:1]; (1/4 rate data) 2 Multipurpose register (MPR) access 0 = Normal operation 1 = Data flow from MPR 1:0 MPR page select 00 = Page 0 01 = Page 1 10 = Page 2 11 = Page 3 (restricted for DRAM manufacturer use only) Multipurpose Register The multipurpose register (MPR) is used for several features: • Readout of the contents of the MRn registers • WRITE and READ system patterns used for data bus calibration • Readout of the error frame when the command address parity feature is enabled To enable MPR, issue an MRS command to MR3[2] = 1. MR3[12:11] define the format of read data from the MPR. Prior to issuing the MRS command, all banks must be in the idle state (all banks precharged and tRP met). After MPR is enabled, any subsequent RD or RDA commands will be redirected to a specific mode register. The mode register location is specified with the READ command using address bits. The MR is split into upper and lower halves to align with a burst length limitation of 8. Power-down mode, SELF REFRESH, and any other nonRD/RDA or nonWR/WRA commands are not allowed during MPR mode. The RESET function is supported during MPR mode, which requires device re-initialization. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 50 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 3 WRITE Command Latency When CRC/DM is Enabled The WRITE command latency (WCL) must be set when both write CRC and DM are enabled for write CRC persistent mode. This provides the extra time required when completing a WRITE burst when write CRC and DM are enabled. Fine Granularity Refresh Mode This mode had been added to DDR4 to help combat the performance penalty due to refresh lockout at high densities. Shortening tRFC and increasing cycle time allows more accesses to the chip and can produce higher bandwidth. Temperature Sensor Status This mode directs the DRAM to update the temperature sensor status at MPR Page 2, MPR0 [4,3]. The temperature sensor setting should be updated within 32ms; when an MPR read of the temperature sensor status bits occurs, the temperature sensor status should be no older than 32ms. Per-DRAM Addressability This mode allows commands to be masked on a per device basis providing any device in a rank (devices sharing the same command and address signals) to be programmed individually. As an example, this feature can be used to program different ODT or V REF values on DRAM devices within a given rank. Gear-Down Mode The device defaults in 1/2 rate (1N) clock mode and uses a low frequency MRS command followed by a sync pulse to align the proper clock edge for operating the control lines CS_n, CKE, and ODT when in 1/4 rate (2N) mode. For operation in 1/2 rate mode, no MRS command or sync pulse is required. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 51 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 4 Mode Register 4 Mode register 4 (MR4) controls various device operating modes as shown in the following register definition table. Not all settings listed may be available on a die; only settings required for speed bin support are available. MR4 is written by issuing the MRS command while controlling the states of the BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the following MR4 Register Definition table. Table 16: Address Pin Mapping Address BG1 BG0 BA1 BA0 A17 RAS CAS WE A13 A12 A11 A10 A9 bus _n _n _n Mode register 21 20 19 18 Note: 17 – – – 13 12 11 10 9 A8 A7 A6 A5 A4 A3 A2 A1 A0 8 7 6 5 4 3 2 1 0 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET (MRS) command. Table 17: MR4 Register Definition Mode Register 21 20:18 Description RFU 0 = Must be programmed to 0 1 = Reserved MR select 000 = MR0 001 = MR1 010 = MR2 011 = MR3 100 = MR4 101 = MR5 110 = MR6 111 = DNU 17 N/A on 4Gb and 8Gb, RFU 0 = Must be programmed to 0 1 = Reserved 13 Post Package Repair (PPR mode) 0 = Disabled 1 = Enabled 12 WRITE preamble setting 0 = 1tCK toggle1 1 = 2tCK toggle 11 READ preamble setting 0 = 1tCK toggle1 1 = 2tCK toggle (When operating in 2tCK WRITE preamble mode, CWL must be programmed to a value at least 1 clock greater than the lowest CWL setting supported in the applicable tCK range.) 10 READ preamble training 0 = Disabled 1 = Enabled PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 52 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 4 Table 17: MR4 Register Definition (Continued) Mode Register 9 8:6 Description Self refresh abort mode 0 = Disabled 1 = Enabled CMD (CAL) address latency 000 = 0 clocks (disabled) 001 =3 clocks1 010 = 4 clocks 011 = 5 clocks1 100 = 6 clocks 101 = 8 clocks 110 = Reserved 111 = Reserved 5 soft Post Package Repair (sPPR mode) 0 = Disabled 1 = Enabled 4 Internal VREF monitor 0 = Disabled 1 = Enabled 3 Temperature controlled refresh mode 0 = Disabled 1 = Enabled 2 Temperature controlled refresh range 0 = Normal temperature mode 1 = Extended temperature mode 1 Maximum power savings mode 0 = Normal operation 1 = Enabled 0 RFU 0 = Must be programmed to 0 1 = Reserved Note: 1. Not allowed when 1/4 rate gear-down mode is enabled. Post Package Repair Mode The post package repair (PPR) mode feature is JEDEC optional for 4Gb DDR4 memories. Performing an MPR read to page 2 MPR0 [7] indicates whether PPR mode is available (A7 = 1) or not available (A7 = 0). PPR mode provides a simple and easy repair method of the device after placed in the system. One row per bank group can be repaired. The repair process is irrevocable so great care should be exercised when using. Soft Post Package Repair Mode The soft post package repair (sPPR) mode feature is JEDEC optional for 4Gb and 8Gb DDR4 memories. Performing an MPR read to page 2 MPR0 [6] indicates whether sPPR mode is available (A6 = 1) or not available (A6 = 0). sPPR mode provides a simple and PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 53 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 4 easy repair method of the device after placed in the system. One row per bank group can be repaired. The repair process is revocable by either doing a reset or power-down. WRITE Preamble Programmable WRITE preamble, tWPRE, can be set to 1tCK or 2tCK via the MR4 register. The 1tCK setting is similar to DDR3. However, when operating in 2tCK WRITE preamble mode, CWL must be programmed to a value at least 1 clock greater than the lowest CWL setting supported in the applicable tCK range. READ Preamble Programmable READ preamble tRPRE can be set to 1tCK or 2tCK via the MR4 register. Both the 1tCK and 2tCK DDR4 preamble settings are different from that defined for the DDR3 SDRAM. Both DDR4 READ preamble settings may require the memory controller to train (or read level) its data strobe receivers using the READ preamble training. When operating in 2tCK WRITE preamble mode, CWL must be programmed to a value at least 1 clock greater than the lowest CWL setting supported in the applicable tCK range. Some even settings will require addition of 2 clocks. If the alternate longer CWL was used, the additional clocks will not be required. READ Preamble Training Programmable READ preamble training can be set to 1tCK or 2tCK. This mode can be used by the memory controller to train or READ level its data strobe receivers. Temperature-Controlled Refresh When temperature-controlled refresh mode is enabled, the device may adjust the internal refresh period to be longer than tREFI of the normal temperature range by skipping external REFRESH commands with the proper gear ratio. For example, the DRAM temperature sensor detected less than 45°C. Normal temperature mode covers the range of 0°C to 85°C, while the extended temperature range covers 0°C to 95°C. Command Address Latency COMMAND ADDRESS LATENCY (CAL) is a power savings feature and can be enabled or disabled via the MRS setting. CAL is defined as the delay in clock cycles (tCAL) between a CS_n registered LOW and its corresponding registered command and address. The value of CAL (in clocks) must be programmed into the mode register and is based on the roundup (in clocks) of [tCK(ns)/tCAL(ns)]. Internal VREF Monitor The device generates its own internal V REFDQ. This mode may be enabled during V REFDQ training, and when enabled, V REF,time-short and V REF,time-long need to be increased by 10ns if DQ0, DQ1, DQ2, or DQ3 have 0pF loading. An additional 15ns per pF of loading is also needed. Maximum Power Savings Mode This mode provides the lowest power mode where data retention is not required. When the device is in the maximum power saving mode, it does not need to guarantee data PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 54 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 4 retention or respond to any external command (except the MAXIMUM POWER SAVING MODE EXIT command and during the assertion of RESET_n signal LOW). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 55 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 5 Mode Register 5 Mode register 5 (MR5) controls various device operating modes as shown in the following register definition table. Not all settings listed may be available on a die; only settings required for speed bin support are available. MR5 is written by issuing the MRS command while controlling the states of the BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the following MR5 Register Definition table. Table 18: Address Pin Mapping Address BG1 BG0 BA1 BA0 A17 RAS CAS WE A13 A12 A11 A10 A9 bus _n _n _n Mode register 21 20 19 18 Note: 17 – – – 13 12 11 10 9 A8 A7 A6 A5 A4 A3 A2 A1 A0 8 7 6 5 4 3 2 1 0 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET command. Table 19: MR5 Register Definition Mode Register 21 20:18 Description RFU 0 = Must be programmed to 0 1 = Reserved MR select 000 = MR0 001 = MR1 010 = MR2 011 = MR3 100 = MR4 101 = MR5 110 = MR6 111 = DNU 17 N/A on 4Gb and 8Gb, RFU 0 = Must be programmed to 0 1 = Reserved 13 RFU 0 = Must be programmed to 0 1 = Reserved 12 Data bus inversion (DBI) – READ DBI enable 0 = Disabled 1 = Enabled 11 Data bus inversion (DBI) – WRITE DBI enable 0 = Disabled 1 = Enabled 10 Data mask (DM) 0 = Disabled 1 = Enabled PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 56 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 5 Table 19: MR5 Register Definition (Continued) Mode Register 9 8:6 Description CA parity persistent error mode 0 = Disabled 1 = Enabled Parked ODT value (RTT(Park)) 000 = RTT(Park) disabled 001 = RZQ/4 (60 ohm) 010 = RZQ/2 (120 ohm) 011 = RZQ/6 (40 ohm) 100 = RZQ/1 (240 ohm) 101 = RZQ/5 (48 ohm) 110 = RZQ/3 (80 ohm) 111 = RZQ/7 (34 ohm) 5 ODT input buffer for power-down 0 = Buffer enabled 1 = Buffer disabled 4 CA parity error status 0 = Clear 1 = Error 3 CRC error status 0 = Clear 1 = Error 2:0 CA parity latency mode 000 = Disable 001 = 4 clocks (DDR4-1600/1866/2133) 010 = 5 clocks (DDR4-2400)1 011 = 6 clocks (DDR4-2666) 100 = 8 clocks (DDR4-2933/3200) 101 = Reserved 110 = Reserved 111 = Reserved Note: 1. Not allowed when 1/4 rate gear-down mode is enabled. Data Bus Inversion The DATA BUS INVERSION (DBI) function has been added to the device and is supported only for x8 and x16 configurations (x4 is not supported). The DBI function shares a common pin with the DM and TDQS functions. The DBI function applies to both READ and WRITE operations; Write DBI cannot be enabled at the same time the DM function is enabled. Refer to the TDQS Function Matrix table for valid configurations for all three functions (TDQS/DM/DBI). DBI is not allowed during MPR READ operation; during an MPR read, the DRAM ignores the read DBI enable setting in MR5 bit A12. DBI is not allowed during MPR READ operations. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 57 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 5 Data Mask The DATA MASK (DM) function, also described as a partial write, has been added to the device and is supported only for x8 and x16 configurations (x4 is not supported). The DM function shares a common pin with the DBI and TDQS functions. The DM function applies only to WRITE operations and cannot be enabled at the same time the write DBI function is enabled. Refer to the TDQS Function Matrix table for valid configurations for all three functions (TDQS/DM/DBI). CA Parity Persistent Error Mode Normal CA parity mode (CA parity persistent mode disabled) no longer performs CA parity checking while the parity error status bit remains set at 1. However, with CA parity persistent mode enabled, CA parity checking continues to be performed when the parity error status bit is set to a 1. ODT Input Buffer for Power-Down This feature determines whether the ODT input buffer is on or off during power-down. If the input buffer is configured to be on (enabled during power-down), the ODT input signal must be at a valid logic level. If the input buffer is configured to be off (disabled during power-down), the ODT input signal may be floating and the device does not provide RTT(NOM) termination. However, the device may provide RTT(Park) termination depending on the MR settings. This is primarily for additional power savings. CA Parity Error Status The device will set the error status bit to 1 upon detecting a parity error. The parity error status bit remains set at 1 until the device controller clears it explicitly using an MRS command. CRC Error Status The device will set the error status bit to 1 upon detecting a CRC error. The CRC error status bit remains set at 1 until the device controller clears it explicitly using an MRS command. CA Parity Latency Mode CA parity is enabled when a latency value, dependent on tCK, is programmed; this accounts for parity calculation delay internal to the device. The normal state of CA parity is to be disabled. If CA parity is enabled, the device must ensure there are no parity errors before executing the command. CA parity signal (PAR) covers ACT_n, RAS_n/A16 , CAS_n/A15, WE_n/A14, and the address bus including bank address and bank group bits. The control signals CKE, ODT, and CS_n are not included in the parity calculation. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 58 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 6 Mode Register 6 Mode register 6 (MR6) controls various device operating modes as shown in the following register definition table. Not all settings listed may be available on a die; only settings required for speed bin support are available. MR6 is written by issuing the MRS command while controlling the states of the BGx, BAx, and Ax address pins. The mapping of address pins during the MRS command is shown in the following MR6 Register Definition table. Table 20: Address Pin Mapping Address BG1 BG0 BA1 BA0 A17 RAS CAS WE A13 A12 A11 A10 A9 bus _n _n _n Mode register 21 20 19 18 Note: 17 – – – 13 12 11 10 9 A8 A7 A6 A5 A4 A3 A2 A1 A0 8 7 6 5 4 3 2 1 0 1. RAS_n, CAS_n, and WE_n must be LOW during MODE REGISTER SET command. Table 21: MR6 Register Definition Mode Register 21 20:18 Description RFU 0 = Must be programmed to 0 1 = Reserved MR select 000 = MR0 001 = MR1 010 = MR2 011 = MR3 100 = MR4 101 = MR5 110 = MR6 111 = DNU 17 NA on 4Gb and 8Gb, RFU 0 = Must be programmed to 0 1 = Reserved 13 RFU 0 = Must be programmed to 0 1 = Reserved 12:10 tCCD_L 000 = 4 clocks (≤1333 Mb/s) 001 = 5 clocks (>1333 Mb/s and ≤1866 Mb/s) 010 = 6 clocks (>1866 Mb/s and ≤2400 Mb/s) 011 = 7 clocks (>2400 Mb/s and ≤2666 Mb/s) 100 = 8 clocks (>2666 Mb/s and ≤3200 Mb/s) 101 = Reserved 110 = Reserved 111 = Reserved PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 59 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Mode Register 6 Table 21: MR6 Register Definition (Continued) Mode Register 9, 8 Description RFU 0 = Must be programmed to 0 1 = Reserved 7 VREF Calibration Enable 0 = Disable 1 = Enable 6 VREF Calibration Range 0 = Range 1 1 = Range 2 5:0 tCCD_L VREF Calibration Value See the VREFDQ Range and Levels table in the VREFDQ Calibration section Programming The device controller must program the correct tCCD_L value. tCCD_L will be programmed according to the value defined per operating frequency in the AC parameter table. Although JEDEC specifies the larger of 5nCK or Xns, Micron's DRAM supports the larger of 4nCK or Xns. VREFDQ Calibration Enable VREFDQ calibration is where the device internally generates its own V REFDQ to be used by the DQ input receivers. The V REFDQ value will be output on any DQ of DQ[3:0] for evaluation only. The device controller is responsible for setting and calibrating the internal VREFDQ level using an MRS protocol (adjust up, adjust down, and so on). It is assumed that the controller will use a series of writes and reads in conduction with V REFDQ adjustments to optimize and verify the data eye. Enabling V REFDQ calibration must be used whenever values are being written to the MR6[6:0] register. VREFDQ Calibration Range The device defines two V REFDQ calibration ranges: Range 1 and Range 2. Range 1 supports V REFDQ between 60% and 92% of V DDQ while Range 2 supports V REFDQ between 45% and 77% of V DDQ, as seen in V REFDQ Specification table. Although not a restriction, Range 1 was targeted for module-based designs and Range 2 was added to target pointto-point designs. VREFDQ Calibration Value Fifty settings provide approximately 0.65% of granularity steps sizes for both Range 1 and Range 2 of V REFDQ, as seen in V REFDQ Range and Levels table in the V REFDQ Calibration section. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 60 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. Table 22: Truth Table – Command A[13,11] L H L L L BG BA V H L H L L H V V V V V V V Self refresh entry SRE H L L H L L H V V V V V V V 8, 9, 10 Self refresh exit SRX L H H X X X X X X X X X X X L H H H H V V V V V V V 8, 9, 10, 11 Single-bank PRECHARGE A[9:0] A12/BC_n H H A10/AP BA [1:0] H REF C[2:0] BG[1:0] MRS REFRESH Prev. Pres. CKE CKE ACT_n MODE REGISTER SET Function CS_n WE_n/A14 CAS_n/A15 RAS_n/A16 Notes 1–5 apply to the entire table; Note 6 applies to all READ/WRITE commands Symbol PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Truth Tables Notes OP code 7 PRE H H L H L H L BG BA V V V L V PREA H H L H L H L V V V V V H V Reserved for future use RFU H H L H L H H Bank ACTIVATE ACT H H L L BG BA V WRITE WR H H L H H L L BG BA V V V L CA BC4OTF WRS4 H H L H H L L BG BA V L V L CA BL8OTF WRS8 H H L H H L L BG BA V H V L CA BL8 fixed, BC4 fixed WRITE with auto BC4OTF precharge BL8OTF WRA H H L H H L L BG BA V V V H CA PRECHARGE all banks 61 BL8 fixed, BC4 fixed Row address (RA) RFU Row address (RA) H H L H H L L BG BA V L V H CA H H L H H L L BG BA V H V H CA RD H H L H H L H BG BA V V V L CA BC4OTF RDS4 H H L H H L H BG BA V L V L CA BL8OTF RDS8 H H L H H L H BG BA V H V L CA BL8 fixed, BC4 fixed READ with auto BC4OTF precharge BL8OTF RDA H H L H H L H BG BA V V V H CA RDAS4 H H L H H L H BG BA V L V H CA RDAS8 H H L H H L H BG BA V H V H CA NO OPERATION NOP H H L H H H H V V V V V V V 12 Device DESELECTED DES H H H X X X X X X X X X X X 13 Power-down entry PDE H L H X X X X X X X X X X X 10, 14 10, 14 READ BL8 fixed, BC4 fixed Power-down exit PDX L H H X X X X X X X X X X X ZQ CALIBRATION LONG ZQCL H H L H H H L X X X X X H X ZQ CALIBRATION SHORT ZQCS H H L H H H L X X X X X L X 4Gb: x4, x8, x16 DDR4 SDRAM Truth Tables Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. WRAS4 WRAS8 4Gb: x4, x8, x16 DDR4 SDRAM Truth Tables Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. • BG = Bank group address • BA = Bank address • RA = Row address • CA = Column address • BC_n = Burst chop • X = “Don’t Care” • V = Valid 2. All DDR4 SDRAM commands are defined by states of CS_n, ACT_n, RAS_n/A16, CAS_n/ A15, WE_n/A14, and CKE at the rising edge of the clock. The MSB of BG, BA, RA, and CA are device density- and configuration-dependent. When ACT_n = H, pins RAS_n/A16, CAS_n/A15, and WE_n/A14 are used as command pins RAS_n, CAS_n, and WE_n, respectively. When ACT_n = L, pins RAS_n/A16, CAS_n/A15, and WE_n/A14 are used as address pins A16, A15, and A14, respectively. 3. RESET_n is enabled LOW and is used only for asynchronous reset and must be maintained HIGH during any function. 4. Bank group addresses (BG) and bank addresses (BA) determine which bank within a bank group is being operated upon. For MRS commands, the BG and BA selects the specific mode register location. 5. V means HIGH or LOW (but a defined logic level), and X means either defined or undefined (such as floating) logic level. 6. READ or WRITE bursts cannot be terminated or interrupted, and fixed/on-the-fly (OTF) BL will be defined by MRS. 7. During an MRS command, A17 is RFU and is device density- and configuration-dependent. 8. The state of ODT does not affect the states described in this table. The ODT function is not available during self refresh. 9. VPP and VREF (VREFCA) must be maintained during SELF REFRESH operation. 10. Refer to the Truth Table – CKE table for more details about CKE transition. 11. Controller guarantees self refresh exit to be synchronous. DRAM implementation has the choice of either synchronous or asynchronous. 12. The NO OPERATION (NOP) command may be used only when exiting maximum power saving mode or when entering gear-down mode. 13. The NOP command may not be used in place of the DESELECT command. 14. The power-down mode does not perform any REFRESH operation. 62 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Truth Tables Table 23: Truth Table – CKE Notes 1–7, 9, and 20 apply to the entire table CKE Previous Cycle (n - 1) Present Cycle (n) Command (n) Action (n) Notes L L X Maintain power-down 8, 10, 11 L H DES Power-down exit 8, 10, 12 Self refresh L L X Maintain self refresh 11, 13 L H DES Self refresh exit 8, 13, 14, 15 Bank(s) active H L DES Active power-down entry 8, 10, 12, 16 Reading H L DES Power-down entry 8, 10, 12, 16, 17 Writing H L DES Power-down entry 8, 10, 12, 16, 17 Precharging H L DES Power-down entry 8, 10, 12, 16, 17 Refreshing H L DES Precharge power-down entry 8, 12 All banks idle H L DES Precharge power-down entry 8, 10, 12, 16, 18 H L REFRESH Self refresh 16, 18, 19 Current State Power-down Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Current state is defined as the state of the DDR4 SDRAM immediately prior to clock edge n. 2. CKE (n) is the logic state of CKE at clock edge n; CKE (n-1) was the state of CKE at the previous clock edge. 3. COMMAND (n) is the command registered at clock edge n, and ACTION (n) is a result of COMMAND (n); ODT is not included here. 4. All states and sequences not shown are illegal or reserved unless explicitly described elsewhere in this document. 5. The state of ODT does not affect the states described in this table. The ODT function is not available during self refresh. 6. During any CKE transition (registration of CKE H->L or CKE H->L), the CKE level must be maintained until 1 nCK prior to tCKE (MIN) being satisfied (at which time CKE may transition again). 7. DESELECT and NOP are defined in the Truth Table – Command table. 8. For power-down entry and exit parameters, see the Power-Down Modes section. 9. CKE LOW is allowed only if tMRD and tMOD are satisfied. 10. The power-down mode does not perform any REFRESH operations. 11. X = "Don’t Care" (including floating around VREF) in self refresh and power-down. X also applies to address pins. 12. The DESELECT command is the only valid command for power-down entry and exit. 13. VPP and VREFCA must be maintained during SELF REFRESH operation. 14. On self refresh exit, the DESELECT command must be issued on every clock edge occurring during the tXS period. READ or ODT commands may be issued only after tXSDLL is satisfied. 15. The DESELECT command is the only valid command for self refresh exit. 16. Self refresh cannot be entered during READ or WRITE operations. For a detailed list of restrictions see the SELF REFRESH Operation and Power-Down Modes sections. 17. If all banks are closed at the conclusion of the READ, WRITE, or PRECHARGE command, then precharge power-down is entered; otherwise, active power-down is entered. 63 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM NOP Command 18. Idle state is defined as all banks are closed (tRP, tDAL, and so on, satisfied), no data bursts are in progress, CKE is HIGH, and all timings from previous operations are satisfied (tMRD, tMOD, tRFC, tZQinit, tZQoper, tZQCS, and so on), as well as all self refresh exit and power-down exit parameters are satisfied (tXS, tXP, tXSDLL, and so on). 19. Self refresh mode can be entered only from the all banks idle state. 20. For more details about all signals, see the Truth Table – Command table; must be a legal command as defined in the table. NOP Command The NO OPERATION (NOP) command was originally used to instruct the selected DDR4 SDRAM to perform a NOP (CS_n = LOW and ACT_n, RAS_n/A16, CAS_n/A15, and WE_n/A14 = HIGH). This prevented unwanted commands from being registered during idle or wait states. NOP command general support has been removed and the command should not be used unless specifically allowed, which is when exiting maximum power-saving mode or when entering gear-down mode. DESELECT Command The deselect function (CS_n HIGH) prevents new commands from being executed; therefore, with this command, the device is effectively deselected. Operations already in progress are not affected. DLL-Off Mode DLL-off mode is entered by setting MR1 bit A0 to 0, which will disable the DLL for subsequent operations until the A0 bit is set back to 1. The MR1 A0 bit for DLL control can be switched either during initialization or during self refresh mode. Refer to the Input Clock Frequency Change section for more details. The maximum clock frequency for DLL-off mode is specified by the parameter tCKDLL_OFF. There is no minimum frequency limit besides the need to satisfy the refresh interval, tREFI. Due to latency counter and timing restrictions, only one CL value and CWL value (in MR0 and MR2 respectively) are supported. The DLL-off mode is only required to support setting both CL = 10 and CWL = 9. DLL-off mode will affect the read data clock-to-data strobe relationship (tDQSCK), but not the data strobe-to-data relationship (tDQSQ, tQH). Special attention is needed to line up read data to the controller time domain. Compared with DLL-on mode, where tDQSCK starts from the rising clock edge (AL + CL) cycles after the READ command, the DLL-off mode tDQSCK starts (AL + CL - 1) cycles after the READ command. Another difference is that tDQSCK may not be small compared to tCK (it might even be larger than tCK), and the difference between tDQSCK (MIN) and tDQSCK (MAX) is significantly larger than in DLL-on mode. The tDQSCK (DLL-off) values are vendor-specific. The timing relations on DLL-off mode READ operation are shown in the following diagram, where CL = 10, AL = 0, and BL = 8. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 64 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM DLL-Off Mode Figure 12: DLL-Off Mode Read Timing Operation T0 CK_c CK_t Command Address (( )) (( )) (( )) RD (( )) (( )) (( )) A RD (( )) (( )) (( )) DQS_t, DQS_c (( )) T1 T6 T7 T8 T9 DES DES DES DES DES T10 T11 DES T12 DES T13 DES DES T14 DES RL (DLL-on) = AL + CL = 10 CL = 10, AL = 0 (DLL-on) tDQSCK DQS_c tDQSCK (MIN) (( )) DIN b (DLL-on) DIN b+1 (MAX) DIN b+2 DIN b+3 DIN b+4 DIN b+5 DIN b+6 DIN b+7 RL (DLL-off) = AL + (CL - 1) = 9 CL = 10, AL = 0 DQS_t, DQS_c (DLL-off) DQS_c (DLL-off) DQS_t, DQS_c (DLL-off) DQS_c (DLL-off) tDQSCK (( )) (( )) DIN b DIN b+1 (DLL-off) MIN DIN b+2 DIN b+3 tDQSCK (( )) (( )) DIN b DIN b+4 DIN b+5 DIN b+6 (DLL-off) MAX DIN b+1 DIN b+2 DIN b+3 DIN b+4 Transitioning data PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 65 DIN b+7 DIN b+5 DIN b+6 DIN b+7 Don’t Care Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM DLL-On/Off Switching Procedures DLL-On/Off Switching Procedures The DLL-off mode is entered by setting MR1 bit A0 to 0; this will disable the DLL for subsequent operations until the A0 bit is set back to 1. DLL Switch Sequence from DLL-On to DLL-Off To switch from DLL-on to DLL-off requires the frequency to be changed during self refresh, as outlined in the following procedure: 1. Starting from the idle state (all banks pre-charged, all timings fulfilled, and, to disable the DLL, the DRAM on-die termination resistors, RTT(NOM), must be in High-Z before MRS to MR1.) 2. Set MR1 bit A0 to 1 to disable the DLL. 3. Wait tMOD. 4. Enter self refresh mode; wait until tCKSRE/tCKSRE_PAR is satisfied. 5. Change frequency, following the guidelines in the Input Clock Frequency Change section. 6. Wait until a stable clock is available for at least tCKSRX at device inputs. 7. Starting with the SELF REFRESH EXIT command, CKE must continuously be registered HIGH until all tMOD timings from any MRS command are satisfied. In addition, if any ODT features were enabled in the mode registers when self refresh mode was entered, the ODT signal must continuously be registered LOW until all tMOD timings from any MRS command are satisfied. If R TT(NOM) was disabled in the mode registers when self refresh mode was entered, the ODT signal is "Don't Care." 8. Wait tXS_FAST, tXS_ABORT, or tXS, and then set mode registers with appropriate values (an update of CL, CWL, and WR may be necessary; a ZQCL command can also be issued after tXS_FAST). • tXS_FAST: ZQCL, ZQCS, and MRS commands. For MRS commands, only CL and WR/RTP registers in MR0, the CWL register in MR2, and gear-down mode in MR3 may be accessed provided the device is not in per-DRAM addressability mode. Access to other device mode registers must satisfy tXS timing. • tXS_ABORT: If the bit is enabled, then the device aborts any ongoing refresh and does not increment the refresh counter. The controller can issue a valid command after a delay of tXS_ABORT. Upon exiting from self refresh, the device requires a minimum of one extra REFRESH command before it is put back into self refresh mode. This requirement remains the same regardless of the MRS bit setting for self refresh abort. t • XS: ACT, PRE, PREA, REF, SRE, PDE, WR, WRS4, WRS8, WRA, WRAS4, WRAS8, RD, RDS4, RDS8, RDA, RDAS4, and RDAS8. 9. Wait tMOD to complete. The device is ready for the next command. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 66 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM DLL-On/Off Switching Procedures Figure 13: DLL Switch Sequence from DLL-On to DLL-Off Ta Tb0 Tb1 Tc Td Te0 Te1 Tf Tg Th Valid Valid Valid Valid 7 Valid 8 Valid 9 Valid Valid Valid CK_c CK_t tCKSRE/tCKSRE_PAR tIS tCKSRX5 Note 4 tCPDED CKE tXS_FAST Command SRE3 MRS2 SRX6 DES Address tRP tXS_ABORT tIS tXS tCKESR/tCKESR_PAR ODT Valid Enter self refresh Exit self refresh Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. 2. 3. 4. 5. 6. 7. Don’t Care Starting in the idle state. RTT in stable state. Disable DLL by setting MR1 bit A0 to 0. Enter SR. Change frequency. Clock must be stable tCKSRX. Exit SR. Update mode registers allowed with DLL-off settings met. 67 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM DLL-On/Off Switching Procedures DLL-Off to DLL-On Procedure To switch from DLL-off to DLL-on (with required frequency change) during self refresh: 1. Starting from the idle state (all banks pre-charged, all timings fulfilled, and DRAM ODT resistors (RTT(NOM)) must be in High-Z before self refresh mode is entered.) 2. Enter self refresh mode; wait until tCKSRE/tCKSRE_PAR are satisfied. 3. Change frequency (following the guidelines in the Input Clock Frequency Change section). 4. Wait until a stable clock is available for at least tCKSRX at device inputs. 5. Starting with the SELF REFRESH EXIT command, CKE must continuously be registered HIGH until tDLLK timing from the subsequent DLL RESET command is satisfied. In addition, if any ODT features were enabled in the mode registers when self refresh mode was entered, the ODT signal must continuously be registered LOW or HIGH until tDLLK timing from the subsequent DLL RESET command is satisfied. If RTT(NOM) disabled in the mode registers when self refresh mode was entered, the ODT signal is "Don't Care." 6. Wait tXS or tXS_ABORT, depending on bit x in RMy, then set MR1 bit A0 to 0 to enable the DLL. 7. Wait tMRD, then set MR1 bit A8 to 1 to start DLL reset. 8. Wait tMRD, then set mode registers with appropriate values; an update of CL, CWL, and WR may be necessary. After tMOD is satisfied from any proceeding MRS command, a ZQCL command can also be issued during or after tDLLK. 9. Wait for tMOD to complete. Remember to wait tDLLK after DLL RESET before applying any command requiring a locked DLL. In addition, wait for tZQoper in case a ZQCL command was issued. The device is ready for the next command. Figure 14: DLL Switch Sequence from DLL-Off to DLL-On Ta Tb0 Tb1 Tc Td Te0 Te1 Tf Tg Th Valid Valid Valid Valid 7 Valid 7 Valid 7 Valid Valid CK_c CK_t tCKSRE/tCKSRE_PAR Note 1 tIS tCKSRX5 Note 4 tCPDED CKE tXS_ABORT Command SRE3 MRS2 SRX6 DES Address tXS tRP tIS tCKESR/tCKESR_PAR ODT Valid Enter self refresh Exit self refresh Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Valid tMRD Don’t Care 1. Starting in the idle state. 68 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Input Clock Frequency Change 2. 3. 4. 5. 6. 7. 8. Enter SR. Change frequency. Clock must be stable tCKSRX. Exit SR. Set DLL to on by setting MR1 to A0 = 0. Update mode registers. Issue any valid command. Input Clock Frequency Change After the device is initialized, it requires the clock to be stable during almost all states of normal operation. This means that after the clock frequency has been set and is in the stable state, the clock period is not allowed to deviate except for what is allowed by the clock jitter and spread spectrum clocking (SSC) specifications. The input clock frequency can be changed from one stable clock rate to another stable clock rate only when in self refresh mode. Outside of self refresh mode, it is illegal to change the clock frequency. After the device has been successfully placed in self refresh mode and tCKSRE/ tCKSRE_PAR have been satisfied, the state of the clock becomes a "Don’t Care." Following a "Don’t Care," changing the clock frequency is permissible, provided the new clock frequency is stable prior to tCKSRX. When entering and exiting self refresh mode for the sole purpose of changing the clock frequency, the self refresh entry and exit specifications must still be met as outlined in SELF REFRESH Operation. For the new clock frequency, additional MRS commands to MR0, MR2, MR3, MR4, and MR6 may need to be issued to program appropriate CL, CWL, gear-down mode, READ and WRITE preamble, and tCCD_L/tDLLK values. If MR6 is issued prior to self refresh entry for new the tDLLK value, DLL will relock automatically at self refresh exit. However, if MR6 is issued after self refresh entry, MR0 must be issued to reset the DLL. The device input clock frequency can change only within the minimum and maximum operating frequency specified for the particular speed grade. Any frequency change below the minimum operating frequency would require the use of DLL-on mode to DLLoff mode transition sequence (see DLL-On/Off Switching Procedures). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 69 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Write Leveling Write Leveling For better signal integrity, DDR4 memory modules use fly-by topology for the commands, addresses, control signals, and clocks. Fly-by topology has benefits from the reduced number of stubs and their length, but it also causes flight-time skew between clock and strobe at every DRAM on the DIMM. This makes it difficult for the controller to maintain tDQSS, tDSS, and tDSH specifications. Therefore, the device supports a write-leveling feature to allow the controller to compensate for skew. This feature may not be required under some system conditions, provided the host can maintain the tDQSS, tDSS, and tDSH specifications. The memory controller can use the write-leveling feature and feedback from the device to adjust the DQS (DQS_t, DQS_c) to CK (CK_t, CK_c) relationship. The memory controller involved in the leveling must have an adjustable delay setting on DQS to align the rising edge of DQS with that of the clock at the DRAM pin. The DRAM asynchronously feeds back CK, sampled with the rising edge of DQS, through the DQ bus. The controller repeatedly delays DQS until a transition from 0 to 1 is detected. The DQS delay established though this exercise would ensure the tDQSS specification. Besides tDQSS, tDSS and tDSH specifications also need to be fulfilled. One way to achieve this is to combine the actual tDQSS in the application with an appropriate duty cycle and jitter on the DQS signals. Depending on the actual tDQSS in the application, the actual values for tDQSL and tDQSH may have to be better than the absolute limits provided in the AC Timing Parameters section in order to satisfy tDSS and tDSH specifications. A conceptual timing of this scheme is shown below. Figure 15: Write-Leveling Concept, Example 1 T0 T1 T2 T3 T4 T6 T5 T7 CK_c CK_t Source diff_DQS Tn Destination T0 T1 T2 T3 T4 T5 T6 CK_c CK_t diff_DQS DQ diff_DQS DQ 0 0 or 1 0 0 Push DQS to capture the 0-1 transition 1 0 or 1 1 1 DQS driven by the controller during leveling mode must be terminated by the DRAM based on the ranks populated. Similarly, the DQ bus driven by the DRAM must also be terminated at the controller. All data bits carry the leveling feedback to the controller across the DRAM configurations: x4, x8, and x16. On a x16 device, both byte lanes should be leveled independently. Therefore, a separate feedback mechanism should be available for each byte lane. The upper data bits should provide the feedback of the upper diff_DQS(diff_UDQS)-toclock relationship; the lower data bits would indicate the lower diff_DQS(diff_LDQS)to-clock relationship. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 70 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Write Leveling The figure below is another representative way to view the write-leveling procedure. Although it shows the clock varying to a static strobe, this is for illustrative purpose only; the clock does not actually change phase, the strobe is what actually varies. By issuing multiple WL bursts, the DQS strobe can be varied to capture with fair accuracy the time at which the clock edge arrives at the DRAM clock input buffer. Figure 16: Write-Leveling Concept, Example 2 tWLS CK_c 1 1 1 111 1 1 11 1 1 1 1 1 1 1 1 CK_t tWLH CK_c CK_t 0 000 000 000 000 tWLS tWLH CK_c CK_t 0 000 000 X XX X X X 11 1 1 1 1 1 1 1 1 DQS_t/ DQS_c tWLO DQ (CK 0 to 1) DQ (CK 1 to 0) DRAM Setting for Write Leveling and DRAM TERMINATION Function in that Mode The DRAM enters into write-leveling mode if A7 in MR1 is HIGH. When leveling is finished, the DRAM exits write-leveling mode if A7 in MR1 is LOW (see the MR Leveling Procedures table). Note that in write-leveling mode, only DQS terminations are activated and deactivated via the ODT pin, unlike normal operation (see DRAM DRAM TERMINATION Function in Leveling Mode table). Table 24: MR Settings for Leveling Procedures Function MR1 Enable Disable Write leveling enable A7 1 0 Output buffer mode (Q off) A12 0 1 Table 25: DRAM TERMINATION Function in Leveling Mode ODT Pin at DRAM RTT(NOM) with ODT HIGH PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN DQS_t/DQS_c Termination DQ Termination On Off 71 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Write Leveling Table 25: DRAM TERMINATION Function in Leveling Mode (Continued) ODT Pin at DRAM RTT(Park) with ODT LOW Notes: DQS_t/DQS_c Termination DQ Termination On Off 1. In write-leveling mode, with the mode's output buffer either disabled (MR1[bit7] = 1 and MR1[bit12] = 1) or with its output buffer enabled (MR1[bit7] = 1 and MR1[bit12] = 0), all RTT(NOM) and RTT(Park) settings are supported. 2. RTT(WR) is not allowed in write-leveling mode and must be set to disable prior to entering write-leveling mode. Procedure Description The memory controller initiates the leveling mode of all DRAM by setting bit 7 of MR1 to 1. When entering write-leveling mode, the DQ pins are in undefined driving mode. During write-leveling mode, only the DESELECT command is supported, other than MRS commands to change the Qoff bit (MR1[A12]) and to exit write leveling (MR1[A7]). Upon exiting write-leveling mode, the MRS command performing the exit (MR1[A7] = 0) may also change the MR1 bits of TBD. Because the controller levels one rank at a time, the output of other ranks must be disabled by setting MR1 bit A12 to 1. The controller may assert ODT after tMOD, at which time the DRAM is ready to accept the ODT signal. The controller may drive DQS_t LOW and DQS_c HIGH after a delay of tWLDQSEN, at which time the DRAM has applied ODT to these signals. After tDQSL and tWLMRD, the controller provides a single DQS_t, DQS_c edge, which is used by the DRAM to sample CK driven from the controller. tWLMRD (MAX) timing is controller dependent. The DRAM samples CK status with the rising edge of DQS and provides feedback on all the DQ bits asynchronously after tWLO timing. There is a DQ output uncertainty of tWLOE defined to allow mismatch on DQ bits. The tWLOE period is defined from the transition of the earliest DQ bit to the corresponding transition of the latest DQ bit. There are no read strobes (DQS_t, DQS_c) needed for these DQs. The controller samples incoming DQ and either increments or decrements DQS delay setting and launches the next DQS pulse after some time, which is controller dependent. After a 0-to-1 transition is detected, the controller locks the DQS delay setting, and write leveling is achieved for the device. The following figure shows the timing diagram and parameters for the overall write-leveling procedure. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 72 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Write Leveling Figure 17: Write-Leveling Sequence (DQS Capturing CK LOW at T1 and CK HIGH at T2) T1 tWLS T2 tWLH tWLS tWLH CK_c5 CK_t Command MRS2 DES3 DES DES DES DES DES NOP DES DES DES DES DES tMOD ODT tWLDQSEN tDQSL6 tDQSH6 tDQSL6 tDQSH6 diff_DQS4 tWLMRD tWLO tWLO Late Prime DQ1 tWLOE Early Prime DQ1 tWLO tWLOE Undefined Driving Mode tWLO Time Break Don’t Care 1. The device drives leveling feedback on all DQs. 2. MRS: Load MR1 to enter write-leveling mode. 3. diff_DQS is the differential data strobe. Timing reference points are the zero crossings. DQS_t is shown with a solid line; DQS_c is shown with a dotted line. 4. CK_t is shown with a solid dark line; CK_c is shown with a dotted line. 5. DQS needs to fulfill minimum pulse width requirements, tDQSH (MIN) and tDQSL (MIN), as defined for regular WRITEs; the maximum pulse width is system dependent. 6. tWLDQSEN must be satisfied following equation when using ODT: Notes: • DLL = Enable, then tWLDQSEN > tMOD (MIN) + ODTLon + tADC • DLL = Disable, then tWLDQSEN > tMOD (MIN) + tAONAS Write-Leveling Mode Exit Write-leveling mode should be exited as follows: 1. After the last rising strobe edge (see ~T0), stop driving the strobe signals (see ~Tc0). Note that from this point on, DQ pins are in undefined driving mode and will remain undefined, until tMOD after the respective MR command (Te1). 2. Drive ODT pin LOW (tIS must be satisfied) and continue registering LOW (see Tb0). 3. After RTT is switched off, disable write-leveling mode via the MRS command (see Tc2). 4. After tMOD is satisfied (Te1), any valid command can be registered. (MR commands can be issued after tMRD [Td1]). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 73 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Write Leveling Figure 18: Write-Leveling Exit CK_c CK_t Command T0 T1 T2 DES DES DES Ta0 Tb0 DES DES Tc0 Tc1 Tc2 DES DES DES Td0 DES Td1 Valid Te0 DES Te1 Valid tMRD MR1 Address Valid tIS Valid tMOD ODT tADC ODTL (OFF) RTT(DQS_t) RTT(DQS_c) RTT(Park) tADC DQS_t, DQS_c RTT(DQ) (MIN) RTT(NON) (MAX) tWLO DQ1 result = 1 Undefined Driving Mode Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Time Break Don’t Care 1. The DQ result = 1 between Ta0 and Tc0 is a result of the DQS signals capturing CK_t HIGH just after the T0 state. 2. See previous figure for specific tWLO timing. 74 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Command Address Latency Command Address Latency DDR4 supports the command address latency (CAL) function as a power savings feature. This feature can be enabled or disabled via the MRS setting. CAL timing is defined as the delay in clock cycles (tCAL) between a CS_n registered LOW and its corresponding registered command and address. The value of CAL in clocks must be programmed into the mode register (see MR1 Register Definition table) and is based on the equation tCK(ns)/tCAL(ns), rounded up in clocks. Figure 19: CAL Timing Definition 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 CLK CS_n CMD/ADDR tCAL CAL gives the DRAM time to enable the command and address receivers before a command is issued. After the command and the address are latched, the receivers can be disabled if CS_n returns to HIGH. For consecutive commands, the DRAM will keep the command and address input receivers enabled for the duration of the command sequence. Figure 20: CAL Timing Example (Consecutive CS_n = LOW) 1 2 3 4 5 6 7 8 9 10 11 12 CLK CS_n CMD/ADDR PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 75 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Command Address Latency When the CAL mode is enabled, additional time is required for the MRS command to complete. The earliest the next valid command can be issued is tMOD_CAL, which should be equal to tMOD + tCAL. The two following figures are examples. Figure 21: CAL Enable Timing – tMOD_CAL T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Tb0 Tb1 Tb2 Tb3 Command Valid MRS DES DES DES DES DES DES DES Valid Valid Address Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid CK_c CK_t CS_n tCAL tMOD_CAL Settings Old settings Updating settings New settings Time Break Note: Don’t Care 1. CAL mode is enabled at T1. Figure 22: tMOD_CAL, MRS to Valid Command Timing with CAL Enabled T0 T1 Valid DES Ta0 Ta1 Ta2 Tb0 Tb1 Tb2 DES MRS DES DES DES DES Tc0 Tc1 Tc2 DES Valid Valid Valid Valid Valid CK_c CK_t Command tCAL Address Valid Valid tCAL Valid Valid Valid Valid Valid Valid CS_n tMOD_CAL Settings Old settings Updating settings New settings Time Break Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. MRS at Ta1 may or may not modify CAL, tMOD_CAL is computed based on new tCAL setting if modified. 76 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Command Address Latency When the CAL mode is enabled or being enabled, the earliest the next MRS command can be issued is tMRD_CAL is equal to tMOD + tCAL. The two following figures are examples. Figure 23: CAL Enabling MRS to Next MRS Command, tMRD_CAL T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Tb0 Valid MRS DES DES DES DES DES DES Tb1 Tb2 Tb3 DES MRS DES Valid Valid Valid CK_c CK_t Command tCAL Address Valid Valid Valid Valid Valid Valid Valid Valid CS_n tMRD_CAL Settings Old settings Updating settings Updating settings Time Break Note: Don’t Care 1. Command address latency mode is enabled at T1. Figure 24: tMRD_CAL, Mode Register Cycle Time With CAL Enabled 7 7 7D 7D 7D 7E 7E '(6 '(6 056 '(6 '(6 '(6 7E 7F 7F 7F '(6 '(6 056 '(6 9DOLG 9DOLG 9DOLG 9DOLG CK_c CK_t Command 9DOLG W &$/ Address 9DOLG W &$/ 9DOLG 9DOLG 9DOLG 9DOLG 9DOLG 9DOLG CS_n W 05'B&$/ Settings 2OGVHWWLQJV 8SGDWLQJVHWWLQJV 1HZVHWWLQJV 7LPH%UHDN Note: 'RQ¶W&DUH 1. MRS at Ta1 may or may not modify CAL, tMRD_CAL is computed based on new tCAL setting if modified. CAL Examples: Consecutive READ BL8 with two different CALs and 1tCK preamble in different bank group shown in the following figures. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 77 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Figure 25: Consecutive READ BL8, CAL3, 1tCK Preamble, Different Bank Group T0 T1 T2 T3 DES READ T4 T5 T6 T7 T13 T14 T15 DES DES READ DES DES DES T16 T17 T18 T19 T20 DES DES T21 T22 CK_c CK_t CS_n t t CAL = 3 DES Command CAL = 3 DES DES DES DES DES t CCD_S = 4 Bank Group Address Address BG a BG b Bank, Col n Bank, Col b tRPRE tRPST (1nCK) DQS_t, DQS_c DQ DOUT n RL = 11 DOUT n+1 DOUT n+2 DOUT n+4 DOUT n+3 DOUT n+5 DOUT n+6 DOUT n+7 DOUT b DOUT b+7 DOUT b+2 DOUT b+3 DOUT b+4 DOUT b+5 DOUT b+6 DOUT b+7 RL = 11 Transitioning Data Notes: Don’t Care 78 BL = 8, AL = 0, CL = 11, CAL = 3, Preamble = 1tCK. DOUT n = data-out from column n; DOUT b = data-out from column b. DES commands are shown for ease of illustration, other commands may be valid at these times. BL8 setting activated by either MR0[A1:0 = 00] or MR0[A1:0 = 01] and A12 = 1 during READ command at T3 and T7. 5. CA parity = Disable, CS to CA latency = Enable, Read DBI = Disable. 6. Enabling CAL mode does not impact ODT control timings. ODT control timings should be maintained with the same timing relationship relative to the command/address bus as when CAL is disabled. 1. 2. 3. 4. &.BF &.BW 7 7 7 7 7 7 '(6 '(6 5($' '(6 7 7 7 7 7 7 7 7 7 '(6 '(6 5($' '(6 '(6 '(6 '(6 '(6 '(6 7 7 7 7 '(6 '(6 '(6 &6BQ W &RPPDQG '(6 &$/  W &$/  W &&'B6  %DQN*URXS $GGUHVV %*D %*E $GGUHVV %DQN &ROQ %DQN &ROE '(6 W 5367 W 535(Q&. '46BW'46BF '4 '287 Q 5/  '287 Q '287 Q '287 Q '287 Q '287 Q '287 Q '287 Q '287 E '287 E '287 E '287 E '287 E '287 E '287 E '287 E 5/  7UDQVLWLRQLQJ'DWD Notes: 1. 2. 3. 4. 'RQ¶W&DUH BL = 8, AL = 0, CL = 11, CAL = 4, Preamble = 1tCK. DOUT n = data-out from column n; DOUT b = data-out from column b. DES commands are shown for ease of illustration, other commands may be valid at these times. BL8 setting activated by either MR0[A1:0 = 00] or MR0[A1:0 = 01] and A12 = 1 during READ command at T4 and T8. 4Gb: x4, x8, x16 DDR4 SDRAM Command Address Latency Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. Figure 26: Consecutive READ BL8, CAL4, 1tCK Preamble, Different Bank Group PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 5. CA parity = Disable, CS to CA latency = Enable, Read DBI = Disable. 6. Enabling CAL mode does not impact ODT control timings. ODT control timings should be maintained with the same timing relationship relative to the command/address bus as when CAL is disabled. 79 4Gb: x4, x8, x16 DDR4 SDRAM Command Address Latency Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Low-Power Auto Self Refresh Mode Low-Power Auto Self Refresh Mode An auto self refresh mode is provided for application ease. Auto self refresh mode is enabled by setting MR2[6] = 1 and MR2[7] = 1. The device will manage self refresh entry over the supported temperature range of the DRAM. In this mode, the device will change its self refresh rate as the DRAM operating temperature changes, going lower at low temperatures and higher at high temperatures. Manual Self Refresh Mode If auto self refresh mode is not enabled, the low-power auto self refresh mode register must be manually programmed to one of the three self refresh operating modes. This mode provides the flexibility to select a fixed self refresh operating mode at the entry of the self refresh, according to the system memory temperature conditions. The user is responsible for maintaining the required memory temperature condition for the mode selected during the SELF REFRESH operation. The user may change the selected mode after exiting self refresh and before entering the next self refresh. If the temperature condition is exceeded for the mode selected, there is a risk to data retention resulting in loss of data. Table 26: Auto Self Refresh Mode MR2[7] MR2[6] Low-Power Auto Self Refresh Mode SELF REFRESH Operation Operating Temperature Range for Self Refresh Mode (DRAM TCASE) 0 0 Normal Fixed normal self refresh rate maintains data retention at the normal operating temperature. User is required to ensure that 85°C DRAM TCASE (MAX) is not exceeded to avoid any risk of data loss. 0°C to 85°C 1 0 Extended temperature Fixed high self refresh rate optimizes data retention to support the extended temperature range. 0°C to 95°C 0 1 Reduced temperature Variable or fixed self refresh rate or any other DRAM power consumption reduction control for the reduced temperature range. User is required to ensure 45°C DRAM TCASE (MAX) is not exceeded to avoid any risk of data loss. 0°C to 45°C 1 1 Auto self refresh Auto self refresh mode enabled. Self refresh power consumption and data retention are optimized for any given operating temperature condition. All of the above PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 80 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Low-Power Auto Self Refresh Mode Figure 27: Auto Self Refresh Ranges IDD6 2x refresh rate 1x refresh rate Extended temperature range 1/2x refresh rate Reduced temperature range 25°C PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Normal temperature range 85°C 45°C 81 95°C Tc Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register Multipurpose Register The MULTIPURPOSE REGISTER (MPR) function, MPR access mode, is used to write/ read specialized data to/from the DRAM. The MPR consists of four logical pages, MPR Page 0 through MPR Page 3, with each page having four 8-bit registers, MPR0 through MPR3. Page 0 can be read by any of three readout modes (serial, parallel, or staggered) while Pages 1, 2, and 3 can be read by only the serial readout mode. Page 3 is for DRAM vendor use only. MPR mode enable and page selection is done with MRS commands. Data bus inversion (DBI) is not allowed during MPR READ operation. Once the MPR access mode is enabled (MR3[2] = 1), only the following commands are allowed: MRS, RD, RDA WR, WRA, DES, REF, and RESET; RDA/WRA have the same functionality as RD/WR which means the auto precharge part of RDA/WRA is ignored. Power-down mode and SELF REFRESH command are not allowed during MPR enable node. No other command can be issued within tRFC after a REF command has been issued; 1x refresh (only) is to be used during MPR access mode. While in MPR access mode, MPR read or write sequences must be completed prior to a REFRESH command. Figure 28: MPR Block Diagram Memory core (all banks precharged) Four multipurpose registers (pages), each with four 8-bit registers: MR3 [2] = 1 Data patterns (RD/WR) Error log (RD) Mode registers (RD) DRAM manufacture only (RD) flow data PR M DQ,s DM_n/DBI_n, DQS_t, DQS_c Table 27: MR3 Setting for the MPR Access Mode Address Operation Mode A[12:11] MPR data read format A2 MPR access A[1:0] MPR page selection Description 00 = Serial ........... 01 = Parallel 10 = Staggered .... 11 = Reserved 0 = Standard operation (MPR not enabled) 1 = MPR data flow enabled 00 = Page 0 .... 01 = Page 1 10 = Page 2 .... 11 = Page 3 Table 28: DRAM Address to MPR UI Translation MPR Location [7] [6] [5] [4] [3] [2] [1] [0] DRAM address – Ax A7 A6 A5 A4 A3 A2 A1 A0 MPR UI – UIx UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 82 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register Table 29: MPR Page and MPRx Definitions Address MPR Location [7] [6] [5] [4] [3] [2] [1] [0] Note Read/Write (default value listed) MPR Page 0 – Read or Write (Data Patterns) BA[1:0] 00 = MPR0 0 1 0 1 0 1 0 1 01 = MPR1 0 0 1 1 0 0 1 1 10 = MPR2 0 0 0 0 1 1 1 1 11 = MPR3 0 0 0 0 0 0 0 0 A6 A5 A4 A3 A2 A1 A0 A13 A12 A11 A10 A9 A8 BG1 BG0 BA1 BA0 A17 RAS_n /A16 C2 C1 C0 MPR Page 1 – Read-only (Error Log) BA[1:0] 00 = MPR0 01 = MPR1 A7 CAS_n/A1 WE_n/ 5 A14 10 = MPR2 PAR ACT_n 11 = MPR3 CRC error status CA parity error status CA parity latency: [5] = MR5[2], [4] = MR5[1], [3] = MR5[0] Read-only MPR Page 2 – Read-only (MRS Readout) BA[1:0] 00 = MPR0 PPR support 01 = MPR1 VREFDQ trainging range sPPR support RTT(WR) Temperature sen- CRC write sor status2 enable VREFDQ training value: [6:1] = MR6[5:0] CAS latency: [7:3] = MR0[12,6:4,2] 10 = MPR2 11 = MPR3 RTT(WR) RTT(NOM): [7:5] = MR1[10:8] Read-only Geardown enable CAS write latency [2:0] = MR2[5:3] RTT(Park): [4:2] = MR5[8:6] RON: [1:0] = MR2[2:1] MPR Page 3 – Read-only (Restricted, except for MPR3 [3:0]) BA[1:0] 00 = MPR0 DC DC DC DC DC DC DC DC 01 = MPR1 DC DC DC DC DC DC DC DC 10 = MPR2 DC DC DC DC DC DC DC DC 11 = MPR3 DC DC DC DC MAC MAC MAC MAC Notes: Read-only 1. DC = "Don't Care" 2. MPR[4:3] 00 = Sub 1X refresh; MPR[4:3] 01 = 1X refresh; MPR[4:3] 10 = 2X refresh; MPR[4:3] 11 = Reserved MPR Reads MPR reads are supported using BL8 and BC4 modes. Burst length on-the-fly is not supported for MPR reads. Data bus inversion (DBI) is not allowed during MPR READ operation; the device will ignore the Read DBI enable setting in MR5 [12] when in MPR mode. READ commands for BC4 are supported with a starting column address of A[2:0] = 000 or 100. After power-up, the content of MPR Page 0 has the default values, which are defined in Table 29. MPR page 0 can be rewritten via an MPR WRITE command. The dePDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 83 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register vice maintains the default values unless it is rewritten by the DRAM controller. If the DRAM controller does overwrite the default values (Page 0 only), the device will maintain the new values unless re-initialized or there is power loss. Timing in MPR mode: • Reads (back-to-back) from Page 0 may use tCCD_S or tCCD_L timing between READ commands • Reads (back-to-back) from Pages 1, 2, or 3 may not use tCCD_S timing between READ commands; tCCD_L must be used for timing between READ commands The following steps are required to use the MPR to read out the contents of a mode register (MPR Page x, MPRy). 1. The DLL must be locked if enabled. 2. Precharge all; wait until tRP is satisfied. 3. MRS command to MR3[2] = 1 (Enable MPR data flow), MR3[12:11] = MPR read format, and MR3[1:0] MPR page. a. MR3[12:11] MPR read format: 1. 00 = Serial read format 2. 01 = Parallel read format 3. 10 = staggered read format 4. 11 = RFU b. MR3[1:0] MPR page: 1. 00 = MPR Page 0 2. 01 = MPR Page 1 3. 10 = MPR Page 2 4. 11 = MPR Page 3 4. tMRD and tMOD must be satisfied. 5. Redirect all subsequent READ commands to specific MPRx location. 6. Issue RD or RDA command. a. BA1 and BA0 indicate MPRx location: 1. 00 = MPR0 2. 01 = MPR1 3. 10 = MPR2 4. 11 = MPR3 b. A12/BC = 0 or 1; BL8 or BC4 fixed-only, BC4 OTF not supported. 1. If BL = 8 and MR0 A[1:0] = 01, A12/BC must be set to 1 during MPR READ commands. c. A2 = burst-type dependant: 1. BL8: A2 = 0 with burst order fixed at 0, 1, 2, 3, 4, 5, 6, 7 2. BL8: A2 = 1 not allowed 3. BC4: A2 = 0 with burst order fixed at 0, 1, 2, 3, T, T, T, T 4. BC4: A2 = 1 with burst order fixed at 4, 5, 6, 7, T, T, T, T d. A[1:0] = 00, data burst is fixed nibble start at 00. e. Remaining address inputs, including A10, and BG1 and BG0 are "Don’t Care." 7. After RL = AL + CL, DRAM bursts data from MPRx location; MPR readout format determined by MR3[A12,11,1,0]. 8. Steps 5 through 7 may be repeated to read additional MPRx locations. 9. After the last MPRx READ burst, tMPRR must be satisfied prior to exiting. 10. Issue MRS command to exit MPR mode; MR3[2] = 0. 11. After the tMOD sequence is completed, the DRAM is ready for normal operation from the core (such as ACT). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 84 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register MPR Readout Format The MPR read data format can be set to three different settings: serial, parallel, and staggered. MPR Readout Serial Format The serial format is required when enabling the MPR function to read out the contents of an MRx, temperature sensor status, and the command address parity error frame. However, data bus calibration locations (four 8-bit registers) can be programmed to read out any of the three formats. The DRAM is required to drive associated strobes with the read data similar to normal operation (such as using MRS preamble settings). Serial format implies that the same pattern is returned on all DQ lanes, as shown the table below, which uses values programmed into the MPR via [7:0] as 0111 1111. Table 30: MPR Readout Serial Format Serial UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7 DQ0 0 1 1 1 1 1 1 1 DQ1 0 1 1 1 1 1 1 1 DQ2 0 1 1 1 1 1 1 1 DQ3 0 1 1 1 1 1 1 1 DQ0 0 1 1 1 1 1 1 1 DQ1 0 1 1 1 1 1 1 1 DQ2 0 1 1 1 1 1 1 1 DQ3 0 1 1 1 1 1 1 1 DQ4 0 1 1 1 1 1 1 1 DQ5 0 1 1 1 1 1 1 1 DQ6 0 1 1 1 1 1 1 1 DQ7 0 1 1 1 1 1 1 1 DQ0 0 1 1 1 1 1 1 1 DQ1 0 1 1 1 1 1 1 1 DQ2 0 1 1 1 1 1 1 1 DQ3 0 1 1 1 1 1 1 1 DQ4 0 1 1 1 1 1 1 1 DQ5 0 1 1 1 1 1 1 1 DQ6 0 1 1 1 1 1 1 1 DQ7 0 1 1 1 1 1 1 1 DQ8 0 1 1 1 1 1 1 1 DQ9 0 1 1 1 1 1 1 1 DQ10 0 1 1 1 1 1 1 1 DQ11 0 1 1 1 1 1 1 1 x4 Device x8 Device x16 Device PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 85 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register Table 30: MPR Readout Serial Format (Continued) Serial UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7 DQ12 0 1 1 1 1 1 1 1 DQ13 0 1 1 1 1 1 1 1 DQ14 0 1 1 1 1 1 1 1 DQ15 0 1 1 1 1 1 1 1 MPR Readout Parallel Format Parallel format implies that the MPR data is returned in the first data UI and then repeated in the remaining UIs of the burst, as shown in the table below. Data pattern location 0 is the only location used for the parallel format. RD/RDA from data pattern locations 1, 2, and 3 are not allowed with parallel data return mode. In this example, the pattern programmed in the data pattern location 0 is 0111 1111. The x4 configuration only outputs the first four bits (0111 in this example). For the x16 configuration, the same pattern is repeated on both the upper and lower bytes. Table 31: MPR Readout – Parallel Format Parallel UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7 DQ0 0 0 0 0 0 0 0 0 DQ1 1 1 1 1 1 1 1 1 DQ2 1 1 1 1 1 1 1 1 DQ3 1 1 1 1 1 1 1 1 DQ0 0 0 0 0 0 0 0 0 DQ1 1 1 1 1 1 1 1 1 DQ2 1 1 1 1 1 1 1 1 DQ3 1 1 1 1 1 1 1 1 DQ4 1 1 1 1 1 1 1 1 DQ5 1 1 1 1 1 1 1 1 DQ6 1 1 1 1 1 1 1 1 DQ7 1 1 1 1 1 1 1 1 DQ0 0 0 0 0 0 0 0 0 DQ1 1 1 1 1 1 1 1 1 DQ2 1 1 1 1 1 1 1 1 DQ3 1 1 1 1 1 1 1 1 DQ4 1 1 1 1 1 1 1 1 DQ5 1 1 1 1 1 1 1 1 DQ6 1 1 1 1 1 1 1 1 DQ7 1 1 1 1 1 1 1 1 x4 Device x8 Device x16 Device PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 86 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register Table 31: MPR Readout – Parallel Format (Continued) Parallel UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7 DQ8 0 0 0 0 0 0 0 0 DQ9 1 1 1 1 1 1 1 1 DQ10 1 1 1 1 1 1 1 1 DQ11 1 1 1 1 1 1 1 1 DQ12 1 1 1 1 1 1 1 1 DQ13 1 1 1 1 1 1 1 1 DQ14 1 1 1 1 1 1 1 1 DQ15 1 1 1 1 1 1 1 1 MPR Readout Staggered Format Staggered format of data return is defined as the staggering of the MPR data across the lanes. In this mode, an RD/RDA command is issued to a specific data pattern location and then the data is returned on the DQ from each of the different data pattern locations. For the x4 configuration, an RD/RDA to data pattern location 0 will result in data from location 0 being driven on DQ0, data from location 1 being driven on DQ1, data from location 2 being driven on DQ2, and so on, as shown below. Similarly, an RD/RDA command to data pattern location 1 will result in data from location 1 being driven on DQ0, data from location 2 being driven on DQ1, data from location 3 being driven on DQ2, and so on. Examples of different starting locations are also shown. Table 32: MPR Readout Staggered Format, x4 x4 READ MPR0 Command x4 READ MPR1 Command x4 READ MPR2 Command x4 READ MPR3 Command Stagger UI[7:0] Stagger UI[7:0] Stagger UI[7:0] Stagger UI[7:0] DQ0 MPR0 DQ0 MPR1 DQ0 MPR2 DQ0 MPR3 DQ1 MPR1 DQ1 MPR2 DQ1 MPR3 DQ1 MPR0 DQ2 MPR2 DQ2 MPR3 DQ2 MPR0 DQ2 MPR1 DQ3 MPR3 DQ3 MPR0 DQ3 MPR1 DQ3 MPR2 It is expected that the DRAM can respond to back-to-back RD/RDA commands to the MPR for all DDR4 frequencies so that a sequence (such as the one that follows) can be created on the data bus with no bubbles or clocks between read data. In this case, the system memory controller issues a sequence of RD(MPR0), RD(MPR1), RD(MPR2), RD(MPR3), RD(MPR0), RD(MPR1), RD(MPR2), and RD(MPR3). Table 33: MPR Readout Staggered Format, x4 – Consecutive READs Stagger UI[7:0] UI[15:8] UI[23:16] UI[31:24] UI[39:32] UI[47:40] UI[55:48] UI[63:56] DQ0 MPR0 MPR1 MPR2 MPR3 MPR0 MPR1 MPR2 MPR3 DQ1 MPR1 MPR2 MPR3 MPR0 MPR1 MPR2 MPR3 MPR0 DQ2 MPR2 MPR3 MPR0 MPR1 MPR2 MPR3 MPR0 MPR1 DQ3 MPR3 MPR0 MPR1 MPR2 MPR3 MPR0 MPR1 MPR2 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 87 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register For the x8 configuration, the same pattern is repeated on the lower nibble as on the upper nibble. READs to other MPR data pattern locations follow the same format as the x4 case. A read example to MPR0 for x8 and x16 configurations is shown below. Table 34: MPR Readout Staggered Format, x8 and x16 x8 READ MPR0 Command x16 READ MPR0 Command x16 READ MPR0 Command Stagger UI[7:0] Stagger UI[7:0] Stagger UI[7:0] DQ0 MPR0 DQ0 MPR0 DQ8 MPR0 DQ1 MPR1 DQ1 MPR1 DQ9 MPR1 DQ2 MPR2 DQ2 MPR2 DQ10 MPR2 DQ3 MPR3 DQ3 MPR3 DQ11 MPR3 DQ4 MPR0 DQ4 MPR0 DQ12 MPR0 DQ5 MPR1 DQ5 MPR1 DQ13 MPR1 DQ6 MPR2 DQ6 MPR2 DQ14 MPR2 DQ7 MPR3 DQ7 MPR3 DQ15 MPR3 MPR READ Waveforms The following waveforms show MPR read accesses. Figure 29: MPR READ Timing T0 Ta0 Ta1 Tb0 Tc0 Tc1 Tc2 Tc3 Td0 Td1 DES READ DES DES DES DES DES DES Te0 Tf0 Tf1 Valid 4 DES Valid Valid CK_c CK_t MPE Enable Command tRP Address Valid MPE Disable MRS1 PREA tMOD Valid MRS3 tMPRR Valid Add2 Valid Valid Valid Valid Valid Valid tMOD Valid CKE PL5 + AL + CL DQS_t, DQS_c DQ UI0 UI1 UI2 UI5 UI6 UI7 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. tCCD_S = 4tCK, Read Preamble = 1tCK. 2. Address setting: A[1:0] = 00b (data burst order is fixed starting at nibble, always 00b here) A2 = 0b (for BL = 8, burst order is fixed at 0, 1, 2, 3, 4, 5, 6, 7) BA1 and BA0 indicate the MPR location A10 and other address pins are "Don’t Care," including BG1 and BG0. A12 is "Don’t Care" when MR0 A[1:0] = 00 or 10 and must be 1b when MR0 A[1:0] = 01 3. Multipurpose registers read/write disable (MR3 A2 = 0). 4. Continue with regular DRAM command. 88 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register 5. Parity latency (PL) is added to data output delay when CA parity latency mode is enabled. Figure 30: MPR Back-to-Back READ Timing T0 T1 T2 DES READ DES T3 T4 T5 T6 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Ta8 Ta9 Ta10 DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid CK_c CK_t Command tCCD_S1 Address Valid Add2 Valid Add2 CKE PL3 + AL + CL DQS_t, DQS_c DQ UI0 UI1 UI2 UI3 UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7 UI0 UI1 UI2 UI3 UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7 DQS_t, DQS_c DQ Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. tCCD_S = 4tCK, Read Preamble = 1tCK. 2. Address setting: A[1:0] = 00b (data burst order is fixed starting at nibble, always 00b here) A2 = 0b (for BL = 8, burst order is fixed at 0, 1, 2, 3, 4, 5, 6, 7; for BC = 4, burst order is fixed at 0, 1, 2, 3, T, T, T, T) BA1 and BA0 indicate the MPR location A10 and other address pins are "Don’t Care," including BG1 and BG0. A12 is "Don’t Care" when MR0 A[1:0] = 00 or 10 and must be 1b when MR0 A[1:0] = 01 3. Parity latency (PL) is added to data output delay when CA parity latency mode is enabled. 89 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register Figure 31: MPR READ-to-WRITE Timing T0 T1 T2 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 READ DES DES DES DES DES DES DES DES DES Tb0 Tb1 Tb2 WRITE DES DES Add2 Valid Valid CK_c CK_t Command tMPRR Address Add1 Valid Valid Valid Valid Valid Valid Valid Valid Valid CKE PL3 + AL + CL DQS_t, DQS_c DQ UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7 Time Break Notes: Don’t Care 1. Address setting: A[1:0] = 00b (data burst order is fixed starting at nibble, always 00b here) A2 = 0b (for BL = 8, burst order is fixed at 0, 1, 2, 3, 4, 5, 6, 7) BA1 and BA0 indicate the MPR location A10 and other address pins are "Don’t Care," including BG1 and BG0. A12 is "Don’t Care" when MR0 A[1:0] = 00 and must be 1b when MR0 A[1:0] = 01 2. Address setting: BA1 and BA0 indicate the MPR location A[7:0] = data for MPR BA1 and BA0 indicate the MPR location A10 and other address pins are "Don’t Care" 3. Parity latency (PL) is added to data output delay when CA parity latency mode is enabled. MPR Writes MPR access mode allows 8-bit writes to the MPR location using the address bus A[7:0]. Data bus inversion (DBI) is not allowed during MPR WRITE operation. The DRAM will maintain the new written values unless re-initialized or there is power loss. The following steps are required to use the MPR to write to mode register MPR Page 0, MPRy). 1. The DLL must be locked if enabled. 2. Precharge all; wait until tRP is satisfied. 3. MRS command to MR3[2] = 1 (enable MPR data flow) and MR3[1:0] = 00 (MPR Page 0); 01, 10, and 11 are not allowed. 4. tMRD and tMOD must be satisfied. 5. Redirect all subsequent WRITE commands to specific MPRx location. 6. Issue WR or WRA command: a. BA1 and BA0 indicate MPRx location 1. 00 = MPR0 2. 01 = MPR1 3. 10 = MPR2 4. 11 = MPR3 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 90 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register 7. 8. 9. 10. 11. b. A[7:0] = data for MPR Page 0, mapped A[7:0] to UI[7:0]. c. Remaining address inputs, including A10, and BG1 and BG0 are "Don’t Care." tWR_MPR must be satisfied to complete MPR WRITE. Steps 5 through 7 may be repeated to write additional MPRx locations. After the last MPRx WRITE, tMPRR must be satisfied prior to exiting. Issue MRS command to exit MPR mode; MR3[2] = 0. When the tMOD sequence is completed, the DRAM is ready for normal operation from the core (such as ACT). MPR WRITE Waveforms The following waveforms show MPR write accesses. Figure 32: MPR WRITE and WRITE-to-READ Timing T0 Ta0 Ta1 Tb0 Tc0 Tc1 Tc2 Td0 Td1 Td2 Td3 Td4 Td5 DES WRITE DES DES READ DES DES DES DES DES DES Valid Add Valid Valid Valid Add2 Valid Valid CK_c CK_t MPR Enable Command MRS1 PREA tRP Address Valid tMOD Valid tWR_MPR Valid Add2 Valid CKE PL3 + AL + CL DQS_t, DQS_c DQ UI0 UI1 UI2 UI3 UI4 UI5 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN UI6 UI7 Don’t Care 1. Multipurpose registers read/write enable (MR3 A2 = 1). 2. Address setting: BA1 and BA0 indicate the MPR location A10 and other address pins are "Don’t Care" 3. Parity latency (PL) is added to data output delay when CA parity latency mode is enabled. 91 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register Figure 33: MPR Back-to-Back WRITE Timing T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Ta8 Ta9 Ta10 WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES Valid Valid Add Valid Valid Valid Valid Valid Valid CK_c CK_t Command tWR_MPR Address Add1 Valid Valid Add1 CKE DQS_t, DQS_c DQ Time Break Note: Don’t Care 1. Address setting: BA1 and BA0 indicate the MPR location A[7:0] = data for MPR A10 and other address pins are "Don’t Care" MPR REFRESH Waveforms The following waveforms show MPR accesses interaction with refreshes. Figure 34: REFRESH Timing T0 Ta0 Ta1 Tb0 Tb1 Tb2 Tb3 DES REF2 DES DES DES Tb4 Tc0 Tc1 Tc2 Tc3 Tc4 DES DES DES Valid Valid Valid Valid Valid Valid Valid Valid Valid CK_c CK_t MPR Enable Command MRS1 PREA tRP Address Valid tMOD Valid tRFC Valid Valid Valid Valid Valid Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. Multipurpose registers read/write enable (MR3 A2 = 1). Redirect all subsequent read and writes to MPR locations. 2. 1x refresh is only allowed when MPR mode is enabled. 92 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register Figure 35: READ-to-REFRESH Timing T0 T1 T2 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Ta8 Ta9 Command READ DES DES DES DES DES DES DES DES DES REF2 DES DES Address Add1 Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid CK_c CK_t CKE PL + AL + CL tRFC (4 + 1) + Clocks BL = 8 DQS_t, DQS_c DQ UI0 UI1 UI2 UI3 UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7 BC = 4 DQS_t, DQS_c DQ Time Break Notes: Don’t Care 1. Address setting: A[1:0] = 00b (data burst order is fixed starting at nibble, always 00b here) A2 = 0b (for BL = 8, burst order is fixed at 0, 1, 2, 3, 4, 5, 6, 7) BA1 and BA0 indicate the MPR location A10 and other address pins are "Don’t Care," including BG1 and BG0. A12 is "Don’t Care" when MR0 A[1:0] = 00 or 10, and must be 1b when MR0 A[1:0] = 01 2. 1x refresh is only allowed when MPR mode is enabled. Figure 36: WRITE-to-REFRESH Timing T0 T1 WRITE DES Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 DES DES REF2 DES DES DES Ta6 Ta7 Ta8 Ta9 Ta10 DES DES DES DES DES Valid Valid Valid Valid Valid CK_c CK_t Command tWR_MPR Address Add1 Valid Valid tRFC Valid Valid Valid Valid Valid CKE DQS_t, DQS_c DQ Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. Address setting: BA1 and BA0 indicate the MPR location 93 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Multipurpose Register A[7:0] = data for MPR A10 and other address pins are "Don’t Care" 2. 1x refresh is only allowed when MPR mode is enabled. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 94 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Gear-Down Mode Gear-Down Mode The DDR4 SDRAM defaults in 1/2 rate (1N) clock mode and uses a low-frequency MRS command (the MRS command has relaxed setup and hold) followed by a sync pulse (first CS pulse after MRS setting) to align the proper clock edge for operating the control lines CS_n, CKE, and ODT when in 1/4 rate (2N) mode. Gear-down mode is only supported at DDR4-2666 and faster. For operation in 1/2 rate mode, neither an MRS command or a sync pulse is required. Gear-down mode may only be entered during initialization or self refresh exit and may only be exited during self refresh exit. The general sequence for operation in 1/4 rate during initialization is as follows: 1. The device defaults to a 1N mode internal clock at power-up/reset. 2. Assertion of reset. 3. Assertion of CKE enables the DRAM. 4. MRS is accessed with a low-frequency N × tCK gear-down MRS command. (NtCK static MRS command is qualified by 1N CS_n. ) 5. The memory controller will send a 1N sync pulse with a low-frequency N × tCK NOP command. tSYNC_GEAR is an even number of clocks. The sync pulse is on an even edge clock boundary from the MRS command. 6. Initialization sequence, including the expiration of tDLLK and tZQinit, starts in 2N mode after tCMD_GEAR from 1N sync pulse. The device resets to 1N gear-down mode after entering self refresh. The general sequence for operation in gear-down after self refresh exit is as follows: 1. MRS is set to 1, via MR3[3], with a low-frequency N × tCK gear-down MRS command. a. The NtCK static MRS command is qualified by 1N CS_n, which meets tXS or tXS_ABORT. b. Only a REFRESH command may be issued to the DRAM before the NtCK static MRS command. 2. The DRAM controller sends a 1N sync pulse with a low-frequency N × tCK NOP command. a. tSYNC_GEAR is an even number of clocks. b. The sync pulse is on even edge clock boundary from the MRS command. 3. A valid command not requiring locked DLL is available in 2N mode after tCMD_GEAR from the 1N sync pulse. a. A valid command requiring locked DLL is available in 2N mode after tXSDLL or tDLLK from the 1N sync pulse. 4. If operation is in 1N mode after self refresh exit, N × tCK MRS command or sync pulse is not required during self refresh exit. The minimum exit delay to the first valid command is tXS, or tXS_ABORT. The DRAM may be changed from 2N to 1N by entering self refresh mode, which will reset to 1N mode. Changing from 2N to by any other means can result in loss of data and make operation of the DRAM uncertain. When operating in 2N gear-down mode, the following MR settings apply: • • • • • • PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN CAS latency (MR0[6:4,2]): Even number of clocks Write recovery and read to precharge (MR0[11:9]): Even number of clocks Additive latency (MR1[4:3]): CL - 2 CAS WRITE latency (MR2 A[5:3]): Even number of clocks CS to command/address latency mode (MR4[8:6]): Even number of clocks CA parity latency mode (MR5[2:0]): Even number of clocks 95 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Gear-Down Mode Figure 37: Clock Mode Change from 1/2 Rate to 1/4 Rate (Initialization) TdkN TdkN + Neven CK_c CK_t tDSRX DRAM internal CLK RESET_n CKE tXPR_GEAR tCMD_GEAR tSYNC_GEAR 1N sync pulse 2N mode CS_n NtCKsetup Command NtCKhold NtCKsetup MRS NtCKhold NOP Valid Configure DRAM to 1/4 rate Time Break Don’t Care Figure 38: Clock Mode Change After Exiting Self Refresh TdkN TdkN + Neven CK_c CK_t DRAM internal CLK CKE tCMD_GEAR tSYNC_GEAR tXPR_GEAR 1N sync pulse 2N mode CS_n NtCKsetup Command NtCKhold MRS NtCKsetup NOP NtCKhold Valid Configure DRAM to 1/4 rate Time Break PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 96 Don’t Care Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Figure 39: Comparison Between Gear-Down Disable and Gear-Down Enable T0 T1 T2 T3 T15 T16 T17 T18 T19 T30 T31 T32 T33 T34 T35 T36 T37 T38 DES DES DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t AL = 0 (geardown = disable) Command ACT DO n DQ tRCD = 16 AL = CL - 1 (geardown = disable) Command ACT READ DO n+ 1 DO n+ 2 DO n+ 3 DO n+ 4 DO n+ 5 DO n+ 6 DO n+ 7 RL =CL= 16 (AL = 0) READ DES DES DES DES DES DES DES DES DES DES DO n DQ DES DO n+ 1 DO n+ 2 DES DO n+ 3 DO n+ 4 DES DO n+ 5 DO n+ 6 DES DO n+ 7 RL = AL + CL = 31 (AL = CL - 1 = 15) READ Command ACT READ DES DES DES DES DO n DQ DES DO n+ 1 DO n+ 2 DO n+ 3 DO n+ 4 DES DO n+ 5 DO n+ 6 DES DO n+ 7 AL + CL = RL = 30 (AL = CL - 2 = 14) 97 Time Break Transitioning Data Don’t Care 4Gb: x4, x8, x16 DDR4 SDRAM Gear-Down Mode Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Maximum Power-Saving Mode Maximum Power-Saving Mode Maximum power-saving mode provides the lowest power mode where data retention is not required. When the device is in the maximum power-saving mode, it does not maintain data retention or respond to any external command, except the MAXIMUM POWER SAVING MODE EXIT command and during the assertion of RESET_n signal LOW. This mode is more like a “hibernate mode” than a typical power-saving mode. The intent is to be able to park the DRAM at a very low-power state; the device can be switched to an active state via the per-DRAM addressability (PDA) mode. Maximum Power-Saving Mode Entry Maximum power-saving mode is entered through an MRS command. For devices with shared control/address signals, a single DRAM device can be entered into the maximum power-saving mode using the per-DRAM addressability MRS command. Large CS_n hold time to CKE upon the mode exit could cause DRAM malfunction; as a result, CA parity, CAL, and gear-down modes must be disabled prior to the maximum powersaving mode entry MRS command. The MRS command may use both address and DQ information, as defined in the PerDRAM Addressability section. As illustrated in the figure below, after tMPED from the mode entry MRS command, the DRAM is not responsive to any input signals except CKE, CS_n, and RESET_n. All other inputs are disabled (external input signals may become High-Z). The system will provide a valid clock until tCKMPE expires, at which time clock inputs (CK) should be disabled (external clock signals may become High-Z). Figure 40: Maximum Power-Saving Mode Entry Ta0 Ta1 Ta2 Tb0 Tb1 Tb3 Tc0 Tc1 Tc2 Tc3 Tc4 Tc5 Tc6 Tc7 Tc8 Tc9 Tc10 Tc11 CK_c CK_t tCKMPE MR4[A1=1] MPSM Enable) Command DES MRS DES DES DES tMPED Address Valid CS_n CKE CKE LOW makes CS_n a care; CKE LOW followed by CS_n LOW followed by CKE HIGH exits mode RESET_n Time Break PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 98 Don’t Care Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Maximum Power-Saving Mode Maximum Power-Saving Mode Entry in PDA The sequence and timing required for the maximum power-saving mode with the perDRAM addressability enabled is illustrated in the figure below. Figure 41: Maximum Power-Saving Mode Entry with PDA Ta0 Ta1 Ta2 Tb0 Tb1 Tb3 Tb4 Tb5 Tb6 Tb7 Tb8 Tb9 Tc0 DES DES DES DES DES DES DES DES DES DES DES Tc1 Tc2 Td0 Td1 Td2 CK_c CK_t MR4[A1 = 1] MPSM Enable) Command DES MRS DES tCKMPE CS_n CKE tMPED AL + CWL DQS_t DQS_c tPDA_S tPDA_H DQ RESET_n Time Break Don’t Care CKE Transition During Maximum Power-Saving Mode The following figure shows how to maintain maximum power-saving mode even though the CKE input may toggle. To prevent the device from exiting the mode, CS_n should be HIGH at the CKE LOW-to-HIGH edge, with appropriate setup (tMPX_S) and hold (tMPX_H) timings. Figure 42: Maintaining Maximum Power-Saving Mode with CKE Transition CLK CMD CS_n tMPX_S tMPX_HH CKE RESET_n Don’t Care Maximum Power-Saving Mode Exit To exit the maximum power-saving mode, CS_n should be LOW at the CKE LOW-toHIGH transition, with appropriate setup (tMPX_S) and hold (tMPX_LH) timings, as PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 99 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Maximum Power-Saving Mode shown in the figure below. Because the clock receivers (CK_t, CK_c) are disabled during this mode, CS_n = LOW is captured by the rising edge of the CKE signal. If the CS_n signal level is detected LOW, the DRAM clears the maximum power-saving mode MRS bit and begins the exit procedure from this mode. The external clock must be restarted and be stable by tCKMPX before the device can exit the maximum power-saving mode. During the exit time (tXMP), only NOP and DES commands are allowed: NOP during tMPX_LH and DES the remainder of tXMP. After tXMP expires, valid commands not requiring a locked DLL are allowed; after tXMP_DLL expires, valid commands requiring a locked DLL are allowed. Figure 43: Maximum Power-Saving Mode Exit Ta0 Ta1 Ta2 Ta3 Tb1 Tb0 Tb2 Tb3 Tc0 NOP NOP NOP Tc1 Tc2 Tc4 Td0 Td1 Td2 Td3 Te0 Te1 NOP NOP DES DES DES DES Valid DES DES CK_c CK_t tCKMPX Command tMPX_LH CS_n tMPX_S CKE tXMP tXMP_DLL RESET_n Time Break PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 100 Don’t Care Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Command/Address Parity Command/Address Parity Command/address (CA) parity takes the CA parity signal (PAR) input carrying the parity bit for the generated address and commands signals and matches it to the internally generated parity from the captured address and commands signals. Figure 44: Command/Address Parity Operation DRAM Controller DRAM CMD/ADDR CMD/ADDR Even parity GEN Even parity GEN CMD/ADDR Even parity bit Even parity bit Compare parity bit CA parity is disabled or enabled via an MRS command. If CA parity is enabled by programming a non-zero value to CA parity latency in the MR, the DRAM will ensure that there is no parity error before executing commands. There is an additional delay required for executing the commands versus when parity is disabled. The delay is programmed in the MR when CA parity is enabled (parity latency) and applied to all commands which are registered by CS_n (rising edge of CK_t and falling CS_n). The command is held for the time of the parity latency (PL) before it is executed inside the device. The command captured by the input clock has an internal delay before executing and is determined with PL. When CA parity is enabled, only DES are allowed between valid commands. PAR will go active when the DRAM detects a CA parity error. CA parity covers ACT_n, RAS_n/A16, CAS_n/A15, WE_n/A14, the address bus including bank address and bank group bits, and C[2:0] on 3DS devices; the control signals CKE, ODT, and CS_n are not covered. For example, for a 4Gb x4 monolithic device, parity is computed across BG[1:0], BA[1:0], A16/RAS_n, A15/CAS_n, A14/ WE_n, A[13:0], and ACT_n. The DRAM treats any unused address pins internally as zeros; for example, if a common die has stacked pins but the device is used in a monolithic application, then the address pins used for stacking and not connected are treated internally as zeros. The convention for parity is even parity; for example, valid parity is defined as an even number of ones across the inputs used for parity computation combined with the parity signal. In other words, the parity bit is chosen so that the total number of ones in the transmitted signal, including the parity bit, is even. If a DRAM device detects a CA parity error in any command qualified by CS_n, it will perform the following steps: 1. Ignore the erroneous command. Commands in the MAX NnCK window (tPAR_UNKNOWN) prior to the erroneous command are not guaranteed to be executed. When a READ command in this NnCK window is not executed, the device does not activate DQS outputs. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 101 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Command/Address Parity 2. Log the error by storing the erroneous command and address bits in the MPR error log. 3. Set the parity error status bit in the mode register to 1. The parity error status bit must be set before the ALERT_n signal is released by the DRAM (that is, tPAR_ALERT_ON + tPAR_ALERT_PW (MIN)). 4. Assert the ALERT_n signal to the host (ALERT_n is active LOW) within tPAR_ALERT_ON time. 5. Wait for all in-progress commands to complete. These commands were received tPAR_UNKOWN before the erroneous command. 6. Wait for tRAS (MIN) before closing all the open pages. The DRAM is not executing any commands during the window defined by (tPAR_ALERT_ON + tPAR_ALERT_PW). 7. After tPAR_ALERT_PW (MIN) has been satisfied, the device may de-assert ALERT_n. a. When the device is returned to a known precharged state, ALERT_n is allowed to be de-asserted. 8. After (tPAR_ALERT_PW (MAX)) the DRAM is ready to accept commands for normal operation. Parity latency will be in effect; however, parity checking will not resume until the memory controller has cleared the parity error status bit by writing a zero. The DRAM will execute any erroneous commands until the bit is cleared; unless persistent mode is enabled. • The DRAM should have only DES commands issued around ALERT_n going HIGH such that at least 3 clocks prior and 1 clock plus 3ns after the release of ALERT_n. • It is possible that the device might have ignored a REFRESH command during tPAR_ALERT_PW or the REFRESH command is the first erroneous frame, so it is recommended that extra REFRESH cycles be issued, as needed. • The parity error status bit may be read anytime after tPAR_ALERT_ON + tPAR_ALERT_PW to determine which DRAM had the error. The device maintains the error log for the first erroneous command until the parity error status bit is reset to a zero or a second CA parity occurs prior to resetting. The mode register for the CA parity error is defined as follows: CA parity latency bits are write only, the parity error status bit is read/write, and error logs are read-only bits. The DRAM controller can only program the parity error status bit to zero. If the DRAM controller illegally attempts to write a 1 to the parity error status bit, the DRAM can not be certain that parity will be checked; the DRAM may opt to block the DRAM controller from writing a 1 to the parity error status bit. The device supports persistent parity error mode. This mode is enabled by setting MR5[9] = 1; when enabled, CA parity resumes checking after the ALERT_n is de-asserted, even if the parity error status bit remains a 1. If multiple errors occur before the error status bit is cleared the error log in MPR Page 1 should be treated as "Don’t Care." In persistent parity error mode the ALERT_n pulse will be asserted and de-asserted by the DRAM as defined with the MIN and MAX value tPAR_ALERT_PW. The DRAM controller must issue DESELECT commands once it detects the ALERT_n signal, this response time is defined as tPAR_ALERT_RSP. The following figures capture the flow of events on the CA bus and the ALERT_n signal. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 102 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Command/Address Parity Table 35: Mode Register Setting for CA Parity CA Parity Latency MR5[2:0]1 Applicable Speed Bin 000 = Disabled N/A 001 = 4 clocks 1600, 1866, 2133 010 = 5 clocks 2400 011 = 6 clocks 2666 100 = 8 clocks 2933, 3200 101 = Reserved RFU 110 = Reserved RFU 111 = Reserved RFU Notes: Parity Error Status Parity Persistent Mode MR5 [4] 0 = Clear MR5 [4] 1 = Error Erroneous CA Frame C[2:0], ACT_n, BG1, BG0, BA[1:0], PAR, MR5 [9] 0 = DisabledMR5 A17, A16/RAS_n, A15/ [9] 1 = Enabled CAS_n, A14/WE_n, A[13:0] 1. Parity latency is applied to all commands. 2. Parity latency can be changed only from a CA parity disabled state; for example, a direct change from PL = 3 to PL = 4 is not allowed. The correct sequence is PL = 3 to disabled to PL = 4. 3. Parity latency is applied to WRITE and READ latency. WRITE latency = AL + CWL + PL. READ latency = AL + CL + PL. Figure 45: Command/Address Parity During Normal Operation T0 T1 Valid 2 Valid 2 Ta0 Ta1 Ta2 Tb0 Tc0 Tc1 Valid 2 Error Valid Valid Valid DES2 Td0 Te0 Te1 DES2 Valid 3 Valid 3 CK_c CK_t Command/ Address t > 2nCK tPAR_UNKNOWN 2 tPAR_ALERT_ON t > 1nCK + 3ns tPAR_ALERT_PW 1 ALERT_n Valid 2 DES2 Command execution unknown Error Valid Command not executed Valid 3 Don’t Care Time Break Command executed Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. DRAM is emptying queues. Precharge all and parity checking are off until parity error status bit is cleared. 2. Command execution is unknown; the corresponding DRAM internal state change may or may not occur. The DRAM controller should consider both cases and make sure that the command sequence meets the specifications. 3. Normal operation with parity latency (CA parity persistent error mode disabled). Parity checking is off until parity error status bit is cleared. 103 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Command/Address Parity Figure 46: Persistent CA Parity Error Checking Operation T0 T1 Valid 2 Valid 2 CK_c Ta0 Ta1 Ta2 Tb0 Valid 2 Error Valid Valid Tc0 Tc1 Td0 Te0 Te1 Valid DES DES DES Valid 3 CK_t Command/ Address tPAR_ALERT_RSP tPAR_UNKNOWN 2 tPAR_ALERT_ON t > 2nCK t > 1nCK + 3ns tPAR_ALERT_PW 1 ALERT_n Valid 2 DES Command execution unknown Error Valid Command not executed Valid 3 Don’t Care Command executed Notes: Time Break 1. DRAM is emptying queues. Precharge all and parity check re-enable finished by tPAR_ALERT_PW. 2. Command execution is unknown; the corresponding DRAM internal state change may or may not occur. The DRAM controller should consider both cases and make sure that the command sequence meets the specifications. 3. Normal operation with parity latency and parity checking (CA parity persistent error mode enabled). Figure 47: CA Parity Error Checking – SRE Attempt T1 T0 CK_c Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Td0 Td1 Td2 Td3 Te0 Te1 DES5 Valid 3 CK_t tCPDED Command/ Address DES1, 5 tXP + PL DES1 Error2 DES6 tIS + PL DES6 tIS CKE t > 2nCK tIH tPAR_ALERT_ON Note 4 t > 1nCK + 3ns tPAR_ALERT_PW 1 ALERT_n DES1, 5 DES6 Error2 DES1 Valid 3 DES5 Command execution unknown Command not executed Don’t Care Command executed Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Time Break 1. Only DESELECT command is allowed. 2. SELF REFRESH command error. The DRAM masks the intended SRE command and enters precharge power-down. 3. Normal operation with parity latency (CA parity persistent error mode disabled). Parity checking is off until the parity error status bit cleared. 4. The controller cannot disable the clock until it has been capable of detecting a possible CA parity error. 5. Command execution is unknown; the corresponding DRAM internal state change may or may not occur. The DRAM controller should consider both cases and make sure that the command sequence meets the specifications. 6. Only a DESELECT command is allowed; CKE may go HIGH prior to Tc2 as long as DES commands are issued. 104 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Command/Address Parity Figure 48: CA Parity Error Checking – SRX Attempt T0 Ta0 Ta1 SRX1 DES DES Tb0 Tb1 Tc0 Tc1 Tc2 Td0 Td1 Te0 Tf0 Error2 Valid 2 Valid 2 Valid 2 DES2, 3 DES2, 3 Valid 2, 4, 5 Valid 2, 4, 6 Valid 2, 4, 7 CK_c CK_t Command/ Address t > 2nCK tIS t > 1nCK + 3ns CKE tPAR_UNKNOWN tPAR_ALERT_ON tPAR_ALERT_PW ALERT_n tXS_FAST 8 tXS tXSDLL SRX1 DES Error Valid Valid 4,5,6,7 Valid 3, 5 Command execution unknown Command not executed Time Break Don’t Care Command executed Notes: 1. Self refresh abort = disable: MR4 [9] = 0. 2. Input commands are bounded by tXSDLL, tXS, tXS_ABORT, and tXS_FAST timing. 3. Command execution is unknown; the corresponding DRAM internal state change may or may not occur. The DRAM controller should consider both cases and make sure that the command sequence meets the specifications. 4. Normal operation with parity latency (CA parity persistent error mode disabled). Parity checking off until parity error status bit cleared. 5. Only an MRS (limited to those described in the SELF REFRESH Operation section), ZQCS, or ZQCL command is allowed. 6. Valid commands not requiring a locked DLL. 7. Valid commands requiring a locked DLL. 8. This figure shows the case from which the error occurred after tXS_FAST. An error may also occur after tXS_ABORT and tXS. Figure 49: CA Parity Error Checking – PDE/PDX T1 T0 CK_c Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Td0 Td1 Td2 Td3 Te0 Te1 DES4 Valid 3 CK_t tCPDED Command/ Address DES1 Error2 tXP + PL DES1 DES5 tIS + PL DES5 tIS CKE t > 2nCK tIH tPAR_ALERT_ON t > 1nCK + 3ns tPAR_ALERT_PW 1 ALERT_n DES4 DES5 Command execution unknown Error2 DES1 Command not executed Valid 3 Don’t Care Command executed Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Time Break 1. Only DESELECT command is allowed. 2. Error could be precharge or activate. 3. Normal operation with parity latency (CA parity persistent error mode disabled). Parity checking is off until parity error status bit cleared. 105 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Command/Address Parity 4. Command execution is unknown; the corresponding DRAM internal state change may or may not occur. The DRAM controller should consider both cases and make sure that the command sequence meets the specifications. 5. Only a DESELECT command is allowed; CKE may go HIGH prior to Td2 as long as DES commands are issued. Figure 50: Parity Entry Timing Example – tMRD_PAR Ta0 Ta1 Ta2 Tb0 Tb1 Tb2 DES MRS DES DES MRS DES CK_c CK_t Command Parity latency PL = 0 Updating setting PL = N tMRD_PAR Enable parity Don’t Care Time Break Note: 1. tMRD_PAR = tMOD + N; where N is the programmed parity latency. Figure 51: Parity Entry Timing Example – tMOD_PAR Ta0 Ta1 Ta2 Tb0 Tb1 Tb2 DES MRS DES DES Valid DES CK_c CK_t Command Parity latency PL = 0 Updating setting PL = N tMOD_PAR Enable parity Time Break Note: Don’t Care 1. tMOD_PAR = tMOD + N; where N is the programmed parity latency. Figure 52: Parity Exit Timing Example – tMRD_PAR Ta0 Ta1 Ta2 Tb0 Tb1 Tb2 DES MRS DES DES MRS DES CK_c CK_t Command Parity latency PL = N Updating setting tMRD_PAR Disable parity Time Break Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. tMRD_PAR = tMOD + N; where N is the programmed parity latency. 106 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Command/Address Parity Figure 53: Parity Exit Timing Example – tMOD_PAR Ta0 Ta1 Ta2 Tb0 Tb1 Tb2 DES MRS DES DES Valid DES CK_c CK_t Command Parity latency PL = N Updating setting tMOD_PAR Disable parity Time Break Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. tMOD_PAR = tMOD + N; where N is the programmed parity latency. 107 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Figure 54: CA Parity Flow Diagram CA process start MR5[2:0] set parity latency (PL) MR5[4] set parity error status to 0 MR5[9] enable/disable persistent mode CA latched in Yes CA parity enabled Persistent mode enabled Yes CA parity error No No No MR5[4] = 0 @ ADDR/CMD latched No Yes Yes CA parity error Good CA processed Yes Ignore bad CMD Command execution unknown No Good CA processed Ignore bad CMD 108 Command execution unknown ALERT_n LOW 44 to 144 CKs MR5[4] = 0 Yes @ ADDR/CMD latched Log error/ set parity status No Yes CA error ALERT_n LOW 44 to 144 CKs Internal precharge all Internal precharge all ALERT_n HIGH ALERT_n HIGH Command execution unknown No Good CA processed Normal operation ready Bad CA processed Operation ready? Command execution unknown Normal operation ready MR5[4] reset to 0 if desired Normal operation ready MR5[4] reset to 0 if desired 4Gb: x4, x8, x16 DDR4 SDRAM Command/Address Parity Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. Log error/ set parity status 4Gb: x4, x8, x16 DDR4 SDRAM Per-DRAM Addressability Per-DRAM Addressability DDR4 allows programmability of a single, specific DRAM on a rank. As an example, this feature can be used to program different ODT or V REF values on each DRAM on a given rank. Because per-DRAM addressability (PDA) mode may be used to program optimal VREF for the DRAM, the data set up for first DQ0 transfer or the hold time for the last DQ0 transfer cannot be guaranteed. The DRAM may sample DQ0 on either the first falling or second rising DQS transfer edge. This supports a common implementation between BC4 and BL8 modes on the DRAM. The DRAM controller is required to drive DQ0 to a stable LOW or HIGH state during the length of the data transfer for BC4 and BL8 cases. 1. Before entering PDA mode, write leveling is required. • BL8 or BC4 may be used. 2. Before entering PDA mode, the following MR settings are possible: 3. 4. 5. 6. 7. 8. • RTT(Park) MR5 A[8:6] = Enable • RTT(NOM) MR1 A[10:8] = Enable Enable PDA mode using MR3 [4] = 1. (The default programed value of MR3[4] = 0.) In PDA mode, all MRS commands are qualified with DQ0. The device captures DQ0 by using DQS signals. If the value on DQ0 is LOW, the DRAM executes the MRS command. If the value on DQ0 is HIGH, the DRAM ignores the MRS command. The controller can choose to drive all the DQ bits. Program the desired DRAM and mode registers using the MRS command and DQ0. In PDA mode, only MRS commands are allowed. The MODE REGISTER SET command cycle time in PDA mode, AL + CWL + BL/2 0.5tCK + tMRD_PDA + PL, is required to complete the WRITE operation to the mode register and is the minimum time required between two MRS commands. Remove the device from PDA mode by setting MR3[4] = 0. (This command requires DQ0 = 0.) Note: Removing the device from PDA mode will require programming the entire MR3 when the MRS command is issued. This may impact some PDA values programmed within a rank as the EXIT command is sent to the rank. To avoid such a case, the PDA enable/disable control bit is located in a mode register that does not have any PDA mode controls. In PDA mode, the device captures DQ0 using DQS signals the same as in a normal WRITE operation; however, dynamic ODT is not supported. Extra care is required for the ODT setting. If RTT(NOM) MR1 [10:8] = enable, device data termination needs to be controlled by the ODT pin, and applies the same timing parameters (defined below). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Symbol Parameter DODTLon Direct ODT turnon latency DODTLoff Direct ODT turn off latency tADC RTT change timing skew tAONAS Asynchronous RTT(NOM) turn-on delay tAOFAS Asynchronous RTT(NOM) turn-off delay 109 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Per-DRAM Addressability Figure 55: PDA Operation Enabled, BL8 &.BF &.BW 05$  3'$HQDEOH 056 056 056 W 02' W 05'B3'$ &:/$/3/ '46BW '46BF '4 W 3'$B6 W 3'$B+ '2'7/RII :/ 2'7 '2'7/RQ :/ 577 5773DUN Note: 577120 5773DUN 1. RTT(Park) = Enable; RTT(NOM) = Enable; WRITE preamble set = 2tCK; and DLL = On. Figure 56: PDA Operation Enabled, BC4 CK_c CK_t MR3 A4 = 1 (PDA enable) MRS MRS MRS tMOD tMRD_PDA CWL+AL+PL DQS_t DQS_c DQ0 tPDA_S tPDA_H DODTLoff = WL-3 ODT DODTLon = WL-3 RTT RTT(Park) Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN RTT(NOM) RTT(Park) 1. RTT(Park) = Enable; RTT(NOM) = Enable; WRITE preamble set = 2tCK; and DLL = On. 110 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Per-DRAM Addressability Figure 57: MRS PDA Exit &.BF &.BW 05$  3'$GLVDEOH 056 9DOLG &:/$/3/ W 02'B3'$ '46BW '46BF '4 W 3'$B6 W 3'$B+ '2'7/RII :/ 2'7 '2'7/RQ :/ 577 5773DUN Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 577120 5773DUN 1. RTT(Park) = Enable; RTT(NOM) = Enable; WRITE preamble set = 2tCK; and DLL = On. 111 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM VREFDQ Calibration VREFDQ Calibration The V REFDQ level, which is used by the DRAM DQ input receivers, is internally generated. The DRAM V REFDQ does not have a default value upon power-up and must be set to the desired value, usually via V REFDQ calibration mode. If PDA or PPR modes are used prior to V REFDQ calibration, V REFDQ should initially be set at the midpoint between the VDD,max, and the LOW as determined by the driver and ODT termination selected with wide voltage swing on the input levels and setup and hold times of approximately 0.75UI. The memory controller is responsible for V REFDQ calibration to determine the best internal V REFDQ level. The V REFDQ calibration is enabled/disabled via MR6[7], MR6[6] selects Range 1 (60% to 92.5% of V DDQ) or Range 2 (45% to 77.5% of V DDQ), and an MRS protocol using MR6[5:0] to adjust the V REFDQ level up and down. MR6[6:0] bits can be altered using the MRS command if MR6[7] is disabled. The DRAM controller will likely use a series of writes and reads in conjunction with V REFDQ adjustments to obtain the best V REFDQ, which in turn optimizes the data eye. The internal V REFDQ specification parameters are voltage range, step size, V REF step time, V REF full step time, and V REF valid level. The voltage operating range specifies the minimum required V REF setting range for DDR4 SDRAM devices. The minimum range is defined by V REFDQ,min and V REFDQ,max. As noted, a calibration sequence, determined by the DRAM controller, should be performed to adjust V REFDQ and optimize the timing and voltage margin of the DRAM data input receivers. The internal V REFDQ voltage value may not be exactly within the voltage range setting coupled with the V REF set tolerance; the device must be calibrated to the correct internal V REFDQ voltage. Figure 58: VREFDQ Voltage Range VDDQ VREF,max VREF range VREF,min PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 112 VSWING small System variance VSWING large Total range Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM VREFDQ Calibration VREFDQ Range and Levels Table 36: VREFDQ Range and Levels MR6[5:0] Range 1 MR6[6] 0 Range 2 MR6[6] 1 MR6[5:0] Range 1 MR6[6] 0 Range 2 MR6[6] 1 00 0000 60.00% 45.00% 01 1010 76.90% 61.90% 00 0001 60.65% 45.65% 01 1011 77.55% 62.55% 00 0010 61.30% 46.30% 01 1100 78.20% 63.20% 00 0011 61.95% 46.95% 01 1101 78.85% 63.85% 00 0100 62.60% 47.60% 01 1110 79.50% 64.50% 00 0101 63.25% 48.25% 01 1111 80.15% 65.15% 00 0110 63.90% 48.90% 10 0000 80.80% 65.80% 00 0111 64.55% 49.55% 10 0001 81.45% 66.45% 00 1000 65.20% 50.20% 10 0010 82.10% 67.10% 00 1001 65.85% 50.85% 10 0011 82.75% 67.75% 00 1010 66.50% 51.50% 10 0100 83.40% 68.40% 00 1011 67.15% 52.15% 10 0101 84.05% 69.05% 00 1100 67.80% 52.80% 10 0110 84.70% 69.70% 00 1101 68.45% 53.45% 10 0111 85.35% 70.35% 00 1110 69.10% 54.10% 10 1000 86.00% 71.00% 00 1111 69.75% 54.75% 10 1001 86.65% 71.65% 01 0000 70.40% 55.40% 10 1010 87.30% 72.30% 01 0001 71.05% 56.05% 10 1011 87.95% 72.95% 01 0010 71.70% 56.70% 10 1100 88.60% 73.60% 01 0011 72.35% 57.35% 10 1101 89.25% 74.25% 01 0100 73.00% 58.00% 10 1110 89.90% 74.90% 01 0101 73.65% 58.65% 10 1111 90.55% 75.55% 01 0110 74.30% 59.30% 11 0000 91.20% 76.20% 01 0111 74.95% 59.95% 11 0001 91.85% 76.85% 01 1000 75.60% 60.60% 11 0010 92.50% 77.50% 01 1001 76.25% 61.25% 11 0011 to 11 1111 = Reserved VREFDQ Step Size The V REF step size is defined as the step size between adjacent steps. V REF step size ranges from 0.5% V DDQ to 0.8% V DDQ. However, for a given design, the device has one value for V REF step size that falls within the range. The V REF set tolerance is the variation in the V REF voltage from the ideal setting. This accounts for accumulated error over multiple steps. There are two ranges for V REF set tolerance uncertainty. The range of V REF set tolerance uncertainty is a function of number of steps n. The V REF set tolerance is measured with respect to the ideal line, which is based on the MIN and MAX V REF value endpoints for a specified range. The internal V REFDQ voltage PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 113 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM VREFDQ Calibration value may not be exactly within the voltage range setting coupled with the V REF set tolerance; the device must be calibrated to the correct internal V REFDQ voltage. Figure 59: Example of VREF Set Tolerance and Step Size Actual VREF output Straight line (endpoint fit) VREF VREF set tolerance VREF set tolerance VREF step size Digital Code Note: 1. Maximum case shown. VREFDQ Increment and Decrement Timing The V REF increment/decrement step times are defined by V REF,time. V REF,time is defined from t0 to t1, where t1 is referenced to the V REF voltage at the final DC level within the VREF valid tolerance (VREF,val_tol). The V REF valid level is defined by V REF,val tolerance to qualify the step time t1. This parameter is used to insure an adequate RC time constant behavior of the voltage level change after any V REF increment/decrement adjustment. Note: t0 is referenced to the MRS command clock t1 is referenced to V REF,tol PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 114 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM VREFDQ Calibration Figure 60: VREFDQ Timing Diagram for VREF,time Parameter CK_c CK_t MRS Command VREF setting adjustment DQ VREF Old VREF setting Updating VREF setting New VREF setting VREF_time t0 t1 Don’t Care VREFDQ calibration mode is entered via an MRS command, setting MR6[7] to 1 (0 disables V REFDQ calibration mode) and setting MR6[6] to either 0 or 1 to select the desired range (MR6[5:0] are "Don't Care"). After V REFDQ calibration mode has been entered, VREFDQ calibration mode legal commands may be issued once tVREFDQE has been satisfied. Legal commands for V REFDQ calibration mode are ACT, WR, WRA, RD, RDA, PRE, DES, and MRS to set V REFDQ values, and MRS to exit V REFDQ calibration mode. Also, after VREFDQ calibration mode has been entered, “dummy” WRITE commands are allowed prior to adjusting the V REFDQ value the first time V REFDQ calibration is performed after initialization. Setting V REFDQ values requires MR6[7] be set to 1 and MR6[6] be unchanged from the initial range selection; MR6[5:0] may be set to the desired V REFDQ values. If MR6[7] is set to 0, MR6[6:0] are not written. V REF,time-short or V REF,time-long must be satisfied after each MR6 command to set V REFDQ value before the internal V REFDQ value is valid. If PDA mode is used in conjunction with V REFDQ calibration, the PDA mode requirement that only MRS commands are allowed while PDA mode is enabled is not waived. That is, the only V REFDQ calibration mode legal commands noted above that may be used are the MRS commands: MRS to set V REFDQ values and MRS to exit V REFDQ calibration mode. The last MR6[6:0] setting written to MR6 prior to exiting V REFDQ calibration mode is the range and value used for the internal V REFDQ setting. V REFDQ calibration mode may be exited when the DRAM is in idle state. After the MRS command to exit V REFDQ calibration mode has been issued, DES must be issued until tVREFDQX has been satisfied where any legal command may then be issued. V REFDQ setting should be updated if the die temperature changes too much from the calibration temperature. The following are typical script when applying the above rules for V REFDQ calibration routine when performing V REFDQ calibration in Range 1: • MR6[7:6]10 [5:0]XXXXXXX. – Subsequent legal commands while in V REFDQ calibration mode: ACT, WR, WRA, RD, RDA, PRE, DES, and MRS (to set V REFDQ values and exit V REFDQ calibration mode). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 115 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM VREFDQ Calibration • All subsequent V REFDQ calibration MR setting commands are MR6[7:6]10 [5:0]VVVVVV. – "VVVVVV" are desired settings for V REFDQ. • Issue ACT/WR/RD looking for pass/fail to determine V CENT (midpoint) as needed. • To exit V REFDQ calibration, the last two V REFDQ calibration MR commands are: – MR6[7:6]10 [5:0]VVVVVV* where VVVVVV* = desired value for V REFDQ. – MR6[7]0 [6:0]XXXXXXX to exit V REFDQ calibration mode. The following are typical script when applying the above rules for V REFDQ calibration routine when performing V REFDQ calibration in Range 2: • MR6[7:6]11 [5:0]XXXXXXX. – Subsequent legal commands while in V REFDQ calibration mode: ACT, WR, WRA, RD, RDA, PRE, DES, and MRS (to set V REFDQ values and exit V REFDQ calibration mode). • All subsequent V REFDQ calibration MR setting commands are MR6[7:6]11 [5:0]VVVVVV. – "VVVVVV" are desired settings for V REFDQ. • Issue ACT/WR/RD looking for pass/fail to determine V CENT (midpoint) as needed. • To exit V REFDQ calibration, the last two V REFDQ calibration MR commands are: – MR6[7:6]11 [5:0]VVVVVV* where VVVVVV* = desired value for V REFDQ. – MR6[7]0 [6:0]XXXXXXX to exit V REFDQ calibration mode. Note: Range may only be set or changed when entering V REFDQ calibration mode; changing range while in or exiting V REFDQ calibration mode is illegal. Figure 61: VREFDQ Training Mode Entry and Exit Timing Diagram T0 T1 DES MRS Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 DES CMD DES CMD DES MRS1,2 Td0 Td1 Td2 DES WR DES CK_c CK_t Command tVREFDQE VREFDQ training on tVREFDQX New VREFDQ value or write New VREFDQ value or write VREFDQ training off Don’t Care Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. New VREFDQ values are not allowed with an MRS command during calibration mode entry. 2. Depending on the step size of the latest programmed VREF value, VREF must be satisfied before disabling VREFDQ training mode. 116 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM VREFDQ Calibration Figure 62: VREF Step: Single Step Size Increment Case VREF Voltage VREF (VDDQ(DC)) VREF,val_tol Step size t1 Time Figure 63: VREF Step: Single Step Size Decrement Case VREF Voltage t1 Step size VREF,val_tol VREF (VDDQ(DC)) Time PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 117 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM VREFDQ Calibration Figure 64: VREF Full Step: From VREF,min to VREF,maxCase VREF Voltage VREF,max VREF,val_tol Full range step VREF (VDDQ(DC)) t1 VREF,min Time Figure 65: VREF Full Step: From VREF,max to VREF,minCase VREF Voltage VREF,max Full range step t1 VREF,val_tol VREF,min VREF (VDDQ(DC)) Time VREFDQ Target Settings The V REFDQ initial settings are largely dependant on the ODT termination settings. The table below shows all of the possible initial settings available for V REFDQ training; it is unlikely the lower ODT settings would be used in most cases. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 118 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM VREFDQ Calibration Table 37: VREFDQ Settings (VDDQ = 1.2V) RON 34 ohm 48 ohm ODT Vx – VIN LOW (mV) VREFDQ (mv) VREFDQ (%VDDQ) 34 ohm 600 900 75% 40 ohm 550 875 73% 48 ohm 500 850 71% 60 ohm 435 815 68% 80 ohm 360 780 65% 120 ohm 265 732 61% 240 ohm 150 675 56% 34 ohm 700 950 79% 40 ohm 655 925 77% 48 ohm 600 900 75% 60 ohm 535 865 72% 80 ohm 450 825 69% 120 ohm 345 770 64% 240 ohm 200 700 58% Figure 66: VREFDQ Equivalent Circuit VDDQ VDDQ ODT RXer Vx VREFDQ (internal) RON PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 119 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Connectivity Test Mode Connectivity Test Mode Connectivity test (CT) mode is similar to boundary scan testing but is designed to significantly speed up the testing of electrical continuity of pin interconnections between the device and the memory controller on the PC boards. Designed to work seamlessly with any boundary scan device, CT mode is supported in all x16 devices, and on select x4 and x8 devices (JEDEC specifies CT mode for x4 and x8 as an optional feature on 8Gb and above). Contrary to other conventional shift-register-based test modes, where test patterns are shifted in and out of the memory devices serially during each clock, the CT mode allows test patterns to be entered on the test input pins in parallel and the test results to be extracted from the test output pins of the device in parallel. These two functions are also performed at the same time, significantly increasing the speed of the connectivity check. When placed in CT mode, the device appears as an asynchronous device to the external controlling agent. After the input test pattern is applied, the connectivity test results are available for extraction in parallel at the test output pins after a fixed propagation delay time. Note: A reset of the device is required after exiting CT mode (see RESET and Initialization Procedure). Pin Mapping Only digital pins can be tested using the CT mode. For the purposes of a connectivity check, all the pins used for digital logic in the device are classified as one of the following types: • Test enable (TEN): When asserted HIGH, this pin causes the device to enter CT mode. In CT mode, the normal memory function inside the device is bypassed and the I/O pins appear as a set of test input and output pins to the external controlling agent. Additionally, the device will set the internal V REFDQ to V DDQ × 0.5 during CT mode (this is the only time the DRAM takes direct control over setting the internal V REFDQ). The TEN pin is dedicated to the connectivity check function and will not be used during normal device operation. • Chip select (CS_n): When asserted LOW, this pin enables the test output pins in the device. When de-asserted, these output pins will be High-Z. The CS_n pin in the device serves as the CS_n pin in CT mode. • Test input: A group of pins used during normal device operation designated as test input pins. These pins are used to enter the test pattern in CT mode. • Test output: A group of pins used during normal device operation designated as test output pins. These pins are used for extraction of the connectivity test results in CT mode. • RESET_n: This pin must be fixed high level during CT mode, as in normal function. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 120 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Connectivity Test Mode Table 38: Connectivity Mode Pin Description and Switching Levels CT Mode Pins Pin Name During Normal Memory Operation Switching Level Test enable TEN CMOS (20%/80% VDD) Chip select Test input Test output Notes 1, 2 VREFCA ±200mV 3 BA[1:0], BG[1:0], A[9:0], A10/AP, A11, A12/BC_n, A13, WE_n/A14, A CAS_n/A15, RAS_n/A16, CKE, ACT_n, ODT, CLK_t, CLK_c, PAR VREFCA ±200mV 3 B LDM_n/LDBI_n, UDM_n/LDBI_n; DM_n/DBI_n VREFDQ ±200mV 4 C ALERT_n CMOS (20%/80% VDD) 2, 5 D RESET_n CMOS (20%/80% VDD) 2 VTT ±100mV 6 CS_n DQ[15:0], UDQS_t, UDQS_c, LDQS_t, LDQS_c; DQS_t, DQS_c Notes: 1. TEN: Connectivity test mode is active when TEN is HIGH and inactive when TEN is LOW. TEN must be LOW during normal operation. 2. CMOS is a rail-to-rail signal with DC HIGH at 80% and DC LOW at 20% of VDD (960mV for DC HIGH and 240mV for DC LOW.) 3. VREFCA should be VDD/2. 4. VREFDQ should be VDDQ/2. 5. ALERT_n switching level is not a final setting. 6. VTT should be set to VDD/2. Minimum Terms Definition for Logic Equations The test input and output pins are related by the following equations, where INV denotes a logical inversion operation and XOR a logical exclusive OR operation: MT0 = XOR (A1, A6, PAR) MT1 = XOR (A8, ALERT_n, A9) MT2 = XOR (A2, A5, A13) MT3 = XOR (A0, A7, A11) MT4 = XOR (CK_c, ODT, CAS_n/A15) MT5 = XOR (CKE, RAS_n/A16, A10/AP) MT6 = XOR (ACT_n, A4, BA1) MT7 = x16: XOR (DMU_n/DBIU_n , DML_n/DBIL_n, CK_t) = x8: XOR (BG1, DML_n/DBIL_n, CK_t) = x4: XOR (BG1, CK_t) MT8 = XOR (WE_n/A14, A12 / BC, BA0) MT9 = XOR (BG0, A3, RESET_n and TEN) Logic Equations for a x4 Device, When Supported DQ0 = XOR (MT0, MT1) DQ1 = XOR (MT2, MT3) DQ2 = XOR (MT4, MT5) DQ3 = XOR (MT6, MT7) DQS_t = MT8 DQS_t = MT9 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 121 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Connectivity Test Mode Logic Equations for a x8 Device, When Supported DQ0 = MT0 DQ1 = MT1 DQ2 = MT2 DQ3 = MT3 DQ4 = MT4 DQ5 = MT5 DQ6 = MT6 DQ7 = MT7 DQS_t = MT8 DQS_t = MT9 Logic Equations for a x16 Device DQ0 = MT0 DQ1 = MT1 DQ2 = MT2 DQ3 = MT3 DQ4 = MT4 DQ5 = MT5 DQ6 = MT6 DQ7 = MT7 DQ8 = INV DQ0 DQ9 = INV DQ1 DQ10 = INV DQ2 DQ11 = INV DQ3 DQ12 = INV DQ4 DQ13 = INV DQ5 DQ14 = INV DQ6 DQ15 = INV DQ7 LDQS_t = MT8 LDQS_c = MT9 UDQS_t = INV LDQS_t UDQS_c = INV LDQS_c CT Input Timing Requirements Prior to the assertion of the TEN pin, all voltage supplies must be valid and stable. Upon the assertion of the TEN pin HIGH with RESET_n, CKE and CS_n held HIGH; CLK_t, CLK_c, and CKE signals become test inputs within tCTECT_Valid. The remaining CT inputs become valid tCT_Enable after TEN goes HIGH when CS_n allows input to begin sampling, provided inputs were valid for at least tCT_Valid. While in CT mode, refresh activities in the memory arrays are not allowed; they are initiated either externally (auto refresh) or internally (self refresh). The TEN pin may be asserted after the DRAM has completed power-on. After the DRAM is initialized and V REFDQ is calibrated, CT mode may no longer be used. The TEN pin may be de-asserted at any time in CT mode. Upon exiting CT mode, the states and the integrity of the original content of the memory array are unknown. A full reset of the memory device is required. After CT mode has been entered, the output signals will be stable within tCT_Valid after the test inputs have been applied as long as TEN is maintained HIGH and CS_n is maintained LOW. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 122 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Connectivity Test Mode Figure 67: Connectivity Test Mode Entry Ta Tb Tc Td CK_t Valid input CK_c tCKSRX tCT_IS tIS T = 10ns Valid input tCT_IS CKE Valid input Valid input tCTCKE_Valid T = 200μs T = 500μs RESET_n tCT_IS TEN tCTCKE_Valid tCT_Enable tCT_IS >10ns >0ns CS_n tCT_IS CT Inputs Valid input Valid input tCT_Valid CT Outputs tCT_Valid Valid Valid Don’t Care PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 123 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Post Package Repair and Soft Post Package Repair Post Package Repair and Soft Post Package Repair Post Package Repair DDR4 post package repair (PPR) and soft post package repair (sPPR) repairs 1 row per bank group. JEDEC has PPR as optional for 4Gb and sPPR as optional for 4Gb and 8Gb parts. PPR support is identified via an MPR read from MPR Page 2, MPR0[7]. PPR is a permanent repair; once repaired, it cannot be reversed. sPPR support is identified via an MPR read from MPR Page 2, MPR0[6]. sPPR is NOT a permanent repair; even though repaired, the repair can be reversed or made permanent via PPR. The controller provides the failing row address in the PPR/sPPR sequence to the device to perform the row repair. PPR and sPPR may not be enabled at the same time. PPR defines two fail row address repair sequence modes and users can choose to use either command sequence. The first command sequence uses a WRA command and ensures data retention with a REFRESH operation (except for the bank containing the row that is being repaired). The second command sequence uses a WR command (a REFRESH operation can't be performed in this command sequence). The second command sequence doesn't ensure data retention for the target DRAM. For x16 DRAMs, the lower byte and upper byte are treated as separate bytes; thus each is viewed as a separate x8 device. PPR Row Repair All banks must be precharged and idle. DBI and CRC modes must be disabled. PPR is disabled with MR4[13] = 0, which is the normal state, and PPR is enabled with MR4 [13]= 1, which is the PPR enabled state. There are two forms of PPR mode: 1) WRA initiated (allows refresh of all banks not under repair, and 2) WR initiated (refresh of any bank is not allowed). Both forms of PPR have the same entry requirement as defined in the sections below. PPR Row Repair - Entry As stated above, all banks must be precharged and idle. DBI and CRC modes must be disabled, and all timings must be followed as shown in the timing diagram that follows. All other commands except those listed in the following sequences are illegal. 1. Issue MR4[13] 1 to enter PPR mode enable. a. All DQ are driven HIGH. 2. Issue four consecutive guard key commands (shown in the table below) to MR0 with each command separated by tMOD. a. Any interruption of the key sequence by other commands, such as ACT, WR, RD, PRE, REF, ZQ, and NOP, are not allowed. b. If the guard key bits are not entered in the required order or interrupted with other MR commands, PPR will not be enabled, and the programming cycle will result in a NOP. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 124 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Post Package Repair and Soft Post Package Repair c. When the PPR entry sequence is interrupted and followed by ACT and WR commands, these commands will be conducted as normal DRAM commands. d. JEDEC allows A6:0 to be "Don't Care" on 4Gb and 8Gb devices. Table 39: PPR MR0 Guard Key Settings MR0 BG1:0 BA1:0 A17:12 A11 A10 A9 A8 A7 A6:0 First guard key 0 0 xxxxxx 1 1 0 0 1 1111111 Second guard key 0 0 xxxxxx 0 1 1 1 1 1111111 Third Guard key 0 0 xxxxxx 1 0 1 1 1 1111111 Fourth guard key 0 0 xxxxxx 0 0 1 1 1 1111111 PPR Row Repair – WRA Initiated (REF Commands Allowed) 1. Issue an ACT command with failing BG and BA with the row address to be repaired. 2. Issue a WRA command with BG and BA of failing row address. a. The address must be at valid levels, but the address is "Don't Care." 3. All DQ of the target DRAM should be driven LOW for 4nCK (bit 0 through bit 7) after WL (WL = CWL + AL + PL) in order for PPR to initiate repair. a. Repair will be initiated to the target DRAM only if all DQ during bit 0 through bit 7 are LOW. b. Repair will not be initiated to the target DRAM if any DQ during bit 0 through bit 7 is HIGH. 1. JEDEC states: All DQs of target DRAM should be LOW for 4tCK. If HIGH is driven to all DQs of a DRAM consecutively for equal to or longer than 2tCK, then DRAM does not conduct PPR and retains data if REF command is properly issued; if all DQs are neither LOW for 4tCK nor HIGH for equal to or longer than 2tCK, then PPR mode execution is unknown. c. DQS should function normally. 4. REF command may be issued anytime after the WRA command followed by WL + 4nCK + tWR + tRP + 1tCK. a. Multiple REF commands are issued at a rate of tREFI or tREFI/2, however back-to-back REF commands must be separated by at least tREFI/4 when the DRAM is in PPR mode. b. All banks except the bank under repair will perform refresh. 5. Issue PRE after tPGM time so that the device can repair the target row during tPGM time. a. Wait tPGM_Exit after PRE to allow the device to recognize the repaired target row address. 6. Issue MR4[13] 0 command to PPR mode disable. a. Wait tPGMPST for PPR mode exit to complete. b. After tPGMPST has expired, any valid command may be issued. The entire sequence from PPR mode enable through PPR mode disable may be repeated if more than one repair is to be done. After completing PPR mode, MR0 must be re-programmed to a prePPR mode state if the device is to be accessed. After PPR mode has been exited, the DRAM controller can confirm if the target row was repaired correctly by writing data into the target row and reading it back. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 125 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Post Package Repair and Soft Post Package Repair Figure 68: PPR WRA – Entry T0 T1 Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Td0 Td1 Te0 Tf0 CMD MRS4 DES MRS0 DES MRS0 DES MRS0 DES MRS0 DES ACT WRA DES BG Valid N/A 00 N/A 00 N/A 00 N/A 00 N/A BGf BGf N/A CK_c Tg0 CK_t BA Valid N/A 00 N/A 00 N/A 00 N/A 00 N/A BAf BAf N/A ADDR Valid (A13=1) N/A 1st Key N/A 2nd Key N/A 3rd Key N/A 4th Key N/A Valid Valid N/A CKE DQS_t DQS_c DQs1 tMOD All Banks Precharged and idle state Normal Mode tMOD tMOD 1st Guard Key Validate PPR Entry tMOD 2nd Guard Key Validate tRCD tMOD 3rd Guard Key Validate 4th Guard Key Validate PPR Repair Don’t Care Figure 69: PPR WRA – Repair and Exit Te0 Tf0 CMD ACT BG BGf BA ADDR CK_c Tg0 Tg1 Th0 Th1 Tj0 Tj1 Tj2 WRA DES DES DES BGf N/A N/A N/A BAf BAf N/A N/A Valid Valid N/A N/A Tk0 DES DES REF/DES REF/DES PRE N/A N/A N/A N/A Valid N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Tk1 Tm0 Tm1 Tn0 REF/DES MRSx DES Valid N/A Valid N/A Valid Valid N/A Valid N/A Valid Valid N/A Valid (A13 = 0) N/A Valid CK_t CKE WL = CWL+AL+PL tWR + tRP + 1nCK 4nCK DQS_t DQS_c DQs1 bit 0 All Banks Precharged and idle state bit 1 bit 6 bit 7 tPGM tRCD PPR Repair tPGM_Exit PPR Repair PPR Repair PPR Recognition tPGMPST PPR Exit Normal mode Don’t Care PPR Row Repair – WR Initiated (REF Commands NOT Allowed) 1. Issue an ACT command with failing BG and BA with the row address to be repaired. 2. Issue a WR command with BG and BA of failing row address. a. The address must be at valid levels, but the address is "Don't Care." 3. All DQ of the target DRAM should be driven LOW for 4nCK (bit 0 through bit 7) after WL (WL = CWL + AL + PL) in order for PPR to initiate repair. a. Repair will be initiated to the target DRAM only if all DQ during bit 0 through bit 7 are LOW. b. Repair will not be initiated to the target DRAM if any DQ during bit 0 through bit 7 is HIGH. 1. JEDEC states: All DQs of target DRAM should be LOW for 4tCK. If HIGH is driven to all DQs of a DRAM consecutively for equal to or longer than 2tCK, then DRAM does not conduct PPR and retains data if REF command is properly issued; if all DQs are neither LOW for 4tCK nor HIGH for equal to or longer than 2tCK, then PPR mode execution is unknown. c. DQS should function normally. 4. REF commands may NOT be issued at anytime while in PPT mode. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 126 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Post Package Repair and Soft Post Package Repair 5. Issue PRE after tPGM time so that the device can repair the target row during tPGM time. a. Wait tPGM_Exit after PRE to allow the device to recognize the repaired target row address. 6. Issue MR4[13] 0 command to PPR mode disable. a. Wait tPGMPST for PPR mode exit to complete. b. After tPGMPST has expired, any valid command may be issued. The entire sequence from PPR mode enable through PPR mode disable may be repeated if more than one repair is to be done. After completing PPR mode, MR0 must be re-programmed to a prePPR mode state if the device is to be accessed. After PPR mode has been exited, the DRAM controller can confirm if the target row was repaired correctly by writing data into the target row and reading it back. Figure 70: PPR WR – Entry T0 T1 Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Td0 Td1 Te0 Tf0 CMD MRS4 DES MRS0 DES MRS0 DES MRS0 DES MRS0 DES ACT WR DES BG Valid N/A 00 N/A 00 N/A 00 N/A 00 N/A BGf BGf N/A CK_c Tg0 CK_t BA Valid N/A 00 N/A 00 N/A 00 N/A 00 N/A BAf BAf N/A ADDR Valid (A13 = 1) N/A 1st Key N/A 2nd Key N/A 3rd Key N/A 4th Key N/A Valid Valid N/A CKE WL = CWL + DQS_t DQS_c DQs1 tMOD All Banks Precharged and idle state Normal Mode tMOD tMOD 1st Guard Key Validate PPR Entry tMOD 2nd Guard Key Validate tRCD tMOD 3rd Guard Key Validate 4th Guard Key Validate PPR Repair Don’t Care Figure 71: PPR WR – Repair and Exit Te0 Tf0 CMD ACT BG BGf BA ADDR CK_c Tg0 Tg1 Th0 Th1 Tj0 Tj1 Tj2 WR DES DES DES BGf N/A N/A N/A BAf BAf N/A N/A Valid Valid N/A N/A Tk0 DES DES DES DES PRE N/A N/A N/A N/A Valid N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Tk1 Tm0 Tm1 Tn0 DES MRSx DES Valid N/A Valid N/A Valid Valid N/A Valid N/A Valid Valid N/A Valid (A13 = 0) N/A Valid CK_t CKE WL = CWL + AL + PL 4nCK DQS_t DQS_c DQs1 bit 0 All Banks Precharged and idle state bit 1 bit 6 bit 7 tPGM tRCD PPR Repair tPGM_Exit PPR Repair PPR Repair PPR Recognition tPGMPST PPR Exit Normal mode Don’t Care PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 127 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Post Package Repair and Soft Post Package Repair Table 40: DDR4 PPR Timing Parameters DDR4-1600 through DDR4-3200 Parameter PPR programming time PPR precharge exit time PPR exit time Symbol tPGM Min Max Unit x4, x8 1000 – ms x16 2000 – ms tPGM_Exit 15 – ns tPGMPST 50 – μs sPPR Row Repair Soft post package repair (sPPR) is a way to quickly, but temporarily, repair a row element in a bank group (BG) on a DRAM device, where (hard) PPR takes longer but permanently repairs a row element. sPPR is disabled with MR4[5] = 0, which is the normal state, and sPPR is enabled with MR4[5] = 1, which is the sPPR enabled state. The DRAM will retain the soft repair information as long as V DD remains within the operating region unless rewritten by a subsequent sPPR entry to the same BG. If DRAM power is removed or the DRAM is reset, the soft repair will revert to the unrepaired state. PPR and sPPR may not be enabled at the same time. sPPR must have been disabled and cleared prior to entering PPR mode. With sPPR, DDR4 can repair one row per bank group. When the hard PPR resources for a bank group are used up, the bank group has no more available resources for soft PPR. When a subsequent sPPR request is made to the same BG, the subsequently issued sPPR address will replace the previous sPPR address. If a repair sequence is issued to a bank group with no repair resource available, the DRAM will ignore the programming sequence. All banks must be precharged and idle. DBI and CRC modes must be disabled, and all sPPR timings must be followed as shown in the timing diagram that follows. All other commands except those listed in the following sequences are illegal. 1. Issue MR4[5] 1 to enter sPPR mode enable. a. All DQ are driven HIGH. b. Note that the four guard key commands ARE NOT required for sPPR activation. That being said, JEDEC is may change this specification and require the same guard key as used PPR Mode. A prudent controller design should accommodate either option in case this DRAM is required to change. 2. After tMOD, issue an ACT command with failing BG and BA with the row address to be repaired. 3. After tRCD, issue a WR command with BG and BA of failing row address. a. The address must be at valid levels, but the address is a "Don't Care." 4. All DQ of the target DRAM should be driven LOW for 4nCK (bit 0 through bit 7) after WL (WL = CWL + AL + PL) in order for sPPR to initiate repair. a. Repair will be initiated to the target DRAM only if all DQ during bit 0 through bit 7 are LOW. b. Repair will not be initiated to the target DRAM if any DQ during bit 0 through bit 7 is HIGH. 1. JEDEC states: All DQs of target DRAM should be LOW for 4tCK. If HIGH is driven to all DQs of a DRAM consecutively for equal to or longer than 2tCK, then DRAM does not conduct PPR and retains data if REF com- PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 128 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Post Package Repair and Soft Post Package Repair mand is properly issued; if all DQs are neither LOW for 4tCK nor HIGH for equal to or longer than 2tCK, then PPR mode execution is unknown. c. DQS should function normally. 5. REF command may NOT be issued at anytime while in sPPR mode. 6. Issue PRE after tWR time so that the device can repair the target row during tWR time. a. Wait tPGM_Exit_s after PRE to allow the device to recognize the repaired target row address. 7. Issue MR4[5] 0 command to sPPR mode disable. a. Wait tPGMPST_s for sPPR mode exit to complete. b. After tPGMPST_s has expired, any valid command may be issued. The entire sequence from sPPR mode enable through sPPR mode disable may be repeated if more than one repair is to be done. After sPPR mode has been exited, the DRAM controller can confirm if the target row was repaired correctly by writing data into the target row and reading it back. Figure 72: sPPR – Entry, Repair, and Exit T0 T1 Ta0 Tb0 CMD MRS4 DES ACT BG Valid NA BGf BA Valid NA Valid (A5 = 1) NA CK_c Tc0 Tc1 Td0 Td1 Te0 Te1 Te2 Tf0 WR DES DES DES DES DES DES DES PRE BGf N/A N/A N/A N/A N/A N/A N/A Valid BAf BAf N/A N/A N/A N/A N/A N/A N/A Valid Valid Valid N/A N/A N/A N/A N/A N/A N/A Valid Tf1 Tg0 Tg1 Th0 DES MRS4 DES Valid N/A Valid N/A Valid N/A Valid N/A Valid N/A Valid (A5=0) N/A Valid CK_t ADDR CKE WL = CWL + AL + PL tWR 4nCK DQS_t DQS_c DQs1 bit 0 tMOD All Banks Precharged and idle state Normal Mode bit 1 bit 6 bit 7 tPGM_s tRCD tPGM_Exit_s Normal Mode sPPR Exit sPPR Recognition sPPR Repair sPPR Entry tPGMPST_s Don’t Care Table 41: DDR4 sPPR Timing Parameters DDR4-1600 through DDR4-3200 Parameter Symbol Max Unit RCD (MIN)+ WL + 4nCK + tWR (MIN) – ns sPPR programming time sPPR precharge exit time tPGM_Exit_s 20 – ns tPGMPST_s tMOD – ns sPPR exit time t Min tPGM_s PPR/sPPR Support Identifier Table 42: DDR4 Repair Mode Support Identifier MPR Page 2 MPR0 A7 A6 A5 A4 A3 A2 A1 A0 UI0 UI1 UI2 UI3 UI4 UI5 UI6 UI7 PPR1 sPPR2 RTT_WR Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Temp sensor CRC RTT_WR 1. 0 = PPR mode is not available, 1 = PPR mode is available. 2. 0 = sPPR mode is not available, 1 = sPPR mode is available. 129 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Post Package Repair and Soft Post Package Repair 3. Gray shaded areas are for reference only. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 130 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Target Row Refresh Mode Target Row Refresh Mode Rows can be accessed a limited number of times within a certain time period before adjacent rows require refresh. The maximum activate count (MAC) is the maximum number of activates that a single row can sustain within a time interval of equal to or less than the maximum activate window (tMAW) before the adjacent rows need to be refreshed, regardless of how the activates are distributed over tMAW. The row receiving the excessive actives is the target row (TRn). The two adjacent rows to be refreshed are the victim rows. The MAC values are encoded in MPR Page 3 MPR3[4:0]. Target row refresh (TRR) mode is not required to be used, and in some cases has been rendered inoperable. Micron's DDR4 devices automatically perform TRR mode in the background. Most die will provide an MPR Page 3 MPR3[3:0] of 1000, indicating there is no restriction to the number of ACTIVATE commands to a given row in a refresh period provided DRAM timing specifications are not violated. Table 43: MAC Encoding of MPR Page 3 MPR3 [7] [6] [5] [4] [3] [2] [1] [0] x PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN x x 0 0 0 0 Untested x x x x 0 0 0 1 tMAC x x x x 0 0 1 0 tMAC = 600K x x x x 0 0 1 1 tMAC = 500K 0 tMAC = 400K tMAC = 300K x Note: x MAC x x x 0 1 0 = 700K x x x x 0 1 0 1 x x x x 0 1 1 0 x x x x 0 1 1 1 x x x x 1 0 0 0 Unlimited x x x x 1 0 0 1 Reserved x x x x : : : : Reserved x x x x 1 1 1 1 Reserved Comments The device has not been tested for MAC. Reserved tMAC = 200K There is no restriction to the number of ACTIVATE commands to a given row in a refresh period provided DRAM timing specifications are not violated. 1. MAC encoding in MPR Page 3 MPR3. 131 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM ACTIVATE Command ACTIVATE Command The ACTIVATE command is used to open (activate) a row in a particular bank for subsequent access. The values on the BG[1:0] inputs select the bank group, the BA[1:0] inputs select the bank within the bank group, and the address provided on inputs A[17:0] selects the row within the bank. This row remains active (open) for accesses until a PRECHARGE command is issued to that bank. A PRECHARGE command must be issued before opening a different row in the same bank. Bank-to-bank command timing for ACTIVATE commands uses two different timing parameters, depending on whether the banks are in the same or different bank group. tRRD_S (short) is used for timing between banks located in different bank groups. tRRD_L (long) is used for timing between banks located in the same bank group. Another timing restriction for consecutive ACTIVATE commands [issued at tRRD (MIN)] is tFAW (fifth activate window). Because there is a maximum of four banks in a bank group, the tFAW parameter applies across different bank groups (five ACTIVATE commands issued at tRRD_L (MIN) to the same bank group would be limited by tRC). Figure 73: tRRD Timing CK_c CK_t Command T0 T1 ACT DES T2 T3 T4 T5 T6 DES DES ACT DES DES T8 T9 T10 T11 DES DES DES ACT DES tRRD_L tRRD_S Bank Group (BG) T7 BG a BG b BG b Bank Bank c Bank c Bank d Address Row n Row n Row n Don’t Care Notes: 1. tRRD_S; ACTIVATE-to-ACTIVATE command period (short); applies to consecutive ACTIVATE commands to different bank groups (that is, T0 and T4). 2. tRRD_L; ACTIVATE-to-ACTIVATE command period (long); applies to consecutive ACTIVATE commands to the different banks in the same bank group (that is, T4 and T10). Figure 74: tFAW Timing CK_c CK_t Command T0 ACT Ta0 Valid ACT tRRD Tb0 Valid ACT tRRD Valid Tc0 Tc1 Tc2 ACT Valid Valid tRRD Valid Td0 Td1 ACT NOP tFAW Bank Group (BG) Valid Valid Valid Valid Valid Bank Valid Valid Valid Valid Valid Address Valid Valid Valid Valid Valid Don’t Care Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Time Break 1. tFAW; four activate windows. 132 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM PRECHARGE Command PRECHARGE Command The PRECHARGE command is used to deactivate the open row in a particular bank or the open row in all banks. The bank(s) will be available for a subsequent row activation for a specified time (tRP) after the PRECHARGE command is issued. An exception to this is the case of concurrent auto precharge, where a READ or WRITE command to a different bank is allowed as long as it does not interrupt the data transfer in the current bank and does not violate any other timing parameters. After a bank is precharged, it is in the idle state and must be activated prior to any READ or WRITE commands being issued to that bank. A PRECHARGE command is allowed if there is no open row in that bank (idle state) or if the previously open row is already in the process of precharging. However, the precharge period will be determined by the last PRECHARGE command issued to the bank. The auto precharge feature is engaged when a READ or WRITE command is issued with A10 HIGH. The auto precharge feature uses the RAS lockout circuit to internally delay the PRECHARGE operation until the ARRAY RESTORE operation has completed. The RAS lockout circuit feature allows the PRECHARGE operation to be partially or completely hidden during burst READ cycles when the auto precharge feature is engaged. The PRECHARGE operation will not begin until after the last data of the burst write sequence is properly stored in the memory array. REFRESH Command The REFRESH command (REF) is used during normal operation of the device. This command is nonpersistent, so it must be issued each time a refresh is required. The device requires REFRESH cycles at an average periodic interval of tREFI. When CS_n, RAS_n/A16, and CAS_n/A15 are held LOW and WE_n/A14 HIGH at the rising edge of the clock, the device enters a REFRESH cycle. All banks of the SDRAM must be precharged and idle for a minimum of the precharge time, tRP (MIN), before the REFRESH command can be applied. The refresh addressing is generated by the internal DRAM refresh controller. This makes the address bits “Don’t Care” during a REFRESH command. An internal address counter supplies the addresses during the REFRESH cycle. No control of the external address bus is required once this cycle has started. When the REFRESH cycle has completed, all banks of the SDRAM will be in the precharged (idle) state. A delay between the REFRESH command and the next valid command, except DES, must be greater than or equal to the minimum REFRESH cycle time tRFC (MIN), as shown in Figure 75 (page 134). Note: The tRFC timing parameter depends on memory density. In general, a REFRESH command needs to be issued to the device regularly every tREFI interval. To allow for improved efficiency in scheduling and switching between tasks, some flexibility in the absolute refresh interval is provided for postponing and pullingin the REFRESH command. A limited number REFRESH commands can be postponed depending on refresh mode: a maximum of 8 REFRESH commands can be postponed when the device is in 1X refresh mode; a maximum of 16 REFRESH commands can be postponed when the device is in 2X refresh mode; and a maximum of 32 REFRESH commands can be postponed when the device is in 4X refresh mode. When 8 consecutive REFRESH commands are postponed, the resulting maximum interval between the surrounding REFRESH commands is limited to 9 × tREFI (see Figure 76 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 133 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM REFRESH Command (page 134)). For both the 2X and 4X refresh modes, the maximum consecutive REFRESH commands allowed is limited to 17 × tREFI2 and 36 × tREFI4, respectively. A limited number REFRESH commands can be pulled-in as well. A maximum of 8 additional REFRESH commands can be issued in advance or “pulled-in” in 1X refresh mode, a maximum of 16 additional REFRESH commands can be issued when in advance in 2X refresh mode, and a maximum of 32 additional REFRESH commands can be issued in advance when in 4X refresh mode. Each of these REFRESH commands reduces the number of regular REFRESH commands required later by one. Note that pulling in more than the maximum allowed REFRESH commands in advance does not further reduce the number of regular REFRESH commands required later, so that the resulting maximum interval between two surrounding REFRESH commands is limited to 9 × tREFI (Figure 77 (page 134)), 18 × tRFEI2, or 36 × tREFI4. At any given time, a maximum of 16 REF commands can be issued within 2 × tREF, 32 REF2 commands can be issued within 4 × tREF, and 64 REF4 commands can be issued within 8 × tREFI4. Figure 75: REFRESH Command Timing CK_c T0 T1 REF DES Ta0 Ta1 Tb0 Tb1 Tb2 Tb3 Valid Valid Valid Valid Tc0 Tc1 Tc2 Tc3 REF Valid Valid Valid CK_t Command DES REF tRFC DES DES tRFC Valid (MIN) tREFI (MAX 9 × tREFI) DRAM must be idle DRAM must be idle Time Break Notes: Don’t Care 1. Only DES commands are allowed after a REFRESH command is registered until tRFC (MIN) expires. 2. Time interval between two REFRESH commands may be extended to a maximum of 9 × tREFI. Figure 76: Postponing REFRESH Commands (Example) tREFI 9 × tREFI W tRFC 8 REF-Commands postponed Figure 77: Pulling In REFRESH Commands (Example) 9 × tREFI tREFI W tRFC 8 REF-Commands pulled-in PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 134 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Temperature-Controlled Refresh Mode Temperature-Controlled Refresh Mode During normal operation, temperature-controlled refresh (TCR) mode disabled, the device must have a REFRESH command issued once every tREFI, except for what is allowed by posting (see REFRESH Command section). This means a REFRESH command must be issued once every 3.9μs if T C is greater than or equal to 85°C, and once every 7.8μs if T C is less than 85°C. Table 44: Normal tREFI Refresh (TCR Disabled) Normal Temperature Temperature External Refresh Period Internal Refresh Period 7.8μs 7.8μs TC < 45°C 45°C ≤ TC < 85°C 85°C ≤ TC < 95°C Extended Temperature External Refresh Period Internal Refresh Period 3.9μs1 3.9μs1 N/A 1. If TC is less than 85°C, the external refresh period can be 7.8μs instead of 3.9μs. Note: When TCR mode is enabled, the device will register the externally supplied REFRESH command and adjust the internal refresh period to be longer than tREFI of the normal temperature range, when allowed, by skipping REFRESH commands with the proper gear ratio. TCR mode has two ranges to select between the normal temperature range and the extended temperature range; the correct range must be selected so the internal control operates correctly. The DRAM must have the correct refresh rate applied externally; the internal refresh rate is determined by the DRAM based upon the temperature. TCR Mode – Normal Temperature Range REFRESH commands should be issued to the device with the refresh period equal to or shorter than tREFI of normal temperature range (0°C to 85°C). In this mode, the system guarantees that the temperature does not exceed 85°C. The device may adjust the internal refresh period to be longer than tREFI of the normal temperature range by skipping external REFRESH commands with the proper gear ratio when T C is below 45°C. The internal refresh period is automatically adjusted inside the DRAM, and the DRAM controller does not need to provide any additional control. TCR Mode – Extended Temperature Range REFRESH commands should be issued to the device with the refresh period equal to or shorter than tREFI of extended temperature range (85°C to 95°C). Even though the external refresh supports the extended temperature range, the device will adjust its internal refresh period to tREFI of the normal temperature range by skipping external REFRESH commands with proper gear ratio when operating in the normal temperature range (0°C to 85°C). The device may adjust the internal refresh period to be longer than tREFI of the normal temperature range by skipping external REFRESH commands with the proper gear ratio when T C is below 45°C. The internal refresh period is automatically adjusted inside the DRAM, and the DRAM controller does not need to provide any additional control. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 135 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Temperature-Controlled Refresh Mode Table 45: Normal tREFI Refresh (TCR Enabled) Normal Temperature Range Extended Temperature Range Temperature External Refresh Period Internal Refresh Period TC < 45°C 7.8μs >> 7.8μs 45°C ≤ TC < 85°C 7.8μs 85°C ≤ TC < 95°C External Refresh Period >> 7.8μs 3.9μs1 7.8μs 7.8μs N/A Note: Internal Refresh Period 3.9μs 1. If the external refresh period is 7.8μs, the device will refresh internally at half the listed refresh rate and will violate refresh specifications. Figure 78: TCR Mode Example1 Controller External tREFI 3.9μs REFRESH Internal tREFI 3.9μs REFRESH 95°C to 85°C 85°C to 45°C Below 45°C REFRESH REFRESH REFRESH REFRESH Internal tREFI 7.8μs REFRESH REFRESH REFRESH REFRESH REFRESH REFRESH REFRESH REFRESH REFRESH REFRESH REFRESH REFRESH Controller issues REFRESH commands at extended temperature rate External REFRESH commands are not ignored Every other external REFRESH ignored At low temperature, more REFRESH commands can be ignored Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN REFRESH Internal tREFI >7.8μs REFRESH REFRESH 1. TCR enabled with extended temperature range selected. 136 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Fine Granularity Refresh Mode Fine Granularity Refresh Mode Mode Register and Command Truth Table The REFRESH cycle time (tRFC) and the average refresh interval (tREFI) can be programmed by the MRS command. The appropriate setting in the mode register will set a single set of REFRESH cycle times and average refresh interval for the device (fixed mode), or allow the dynamic selection of one of two sets of REFRESH cycle times and average refresh interval for the device (on-the-fly mode [OTF]). OTF mode must be enabled by MRS before any OTF REFRESH command can be issued. Table 46: MRS Definition MR3[8] MR3[7] MR3[6] Refresh Rate Mode 0 0 0 Normal mode (fixed 1x) 0 0 1 Fixed 2x 0 1 0 Fixed 4x 0 1 1 Reserved 1 0 0 Reserved 1 0 1 On-the-fly 1x/2x 1 1 0 On-the-fly 1x/4x 1 1 1 Reserved There are two types of OTF modes (1x/2x and 1x/4x modes) that are selectable by programming the appropriate values into the mode register. When either of the two OTF modes is selected, the device evaluates the BG0 bit when a REFRESH command is issued, and depending on the status of BG0, it dynamically switches its internal refresh configuration between 1x and 2x (or 1x and 4x) modes, and then executes the corresponding REFRESH operation. Table 47: REFRESH Command Truth Table Refresh RAS_n/A CAS_n/A 15 14 WE_n/ A13 BG1 BG0 A10/ AP A[9:0], A[12:11], A[20:16] MR3[8:6 ] CS_n ACT_n Fixed rate L H L L H V V V V 0vv OTF: 1x L H L L H V L V V 1vv OTF: 2x L H L L H V H V V 101 OTF: 4x L H L L H V H V V 110 tREFI and tRFC Parameters The default refresh rate mode is fixed 1x mode where REFRESH commands should be issued with the normal rate; that is, tREFI1 = tREFI(base) (for T C ≤ 85°C), and the duration of each REFRESH command is the normal REFRESH cycle time (tRFC1). In 2x mode (either fixed 2x or OTF 2x mode), REFRESH commands should be issued to the device at the double frequency (tREFI2 = tREFI(base)/2) of the normal refresh rate. In 4x mode, the REFRESH command rate should be quadrupled (tREFI4 = tREFI(base)/4). Per PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 137 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Fine Granularity Refresh Mode each mode and command type, the tRFC parameter has different values as defined in the following table. For discussion purposes, the REFRESH command that should be issued at the normal refresh rate and has the normal REFRESH cycle duration may be referred to as an REF1x command. The REFRESH command that should be issued at the double frequency (tREFI2 = tREFI(base)/2) may be referred to as a REF2x command. Finally, the REFRESH command that should be issued at the quadruple rate (tREFI4 = tREFI(base)/4) may be referred to as a REF4x command. In the fixed 1x refresh rate mode, only REF1x commands are permitted. In the fixed 2x refresh rate mode, only REF2x commands are permitted. In the fixed 4x refresh rate mode, only REF4x commands are permitted. When the on-the-fly 1x/2x refresh rate mode is enabled, both REF1x and REF2x commands are permitted. When the OTF 1x/4x refresh rate mode is enabled, both REF1x and REF4x commands are permitted. Table 48: tREFI and tRFC Parameters Refresh Mode Parameter tREFI 1x mode 2Gb (base) tREFI1 2x mode 4x mode tRFC4 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 16Gb Units μs 7.8 7.8 7.8 TBD tREFI(base) tREFI(base) tREFI(base) μs 85°C ≤ TC ≤ 95°C tREFI(base)/2 tREFI(base)/2 tREFI(base)/2 tREFI(base)/2 μs 160 260 350 TBD ns 0°C ≤ TC ≤ 85°C tREFI(base)/2 tREFI(base)/2 tREFI(base)/2 tREFI(base)/2 μs 85°C ≤ TC ≤ 95°C tREFI(base)/4 tREFI(base)/4 tREFI(base)/4 tREFI(base)/4 μs 110 160 260 TBD ns 0°C ≤ TC ≤ 85°C tREFI(base)/4 tREFI(base)/4 tREFI(base)/4 tREFI(base)/4 μs 85°C ≤ TC ≤ 95°C tREFI(base)/8 tREFI(base)/8 tREFI(base)/8 tREFI(base)/8 μs 90 110 160 TBD ns 0°C ≤ TC ≤ 85°C tRFC2 tREFI4 8Gb tREFI(base) tRFC1 tREFI2 4Gb 138 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. Extended Temperature Operation – 0°C to 95°C Normal Temperature Operation – 0°C to 85°C 2x Mode (0°C to 85°C) 4x Mode (0°C to 85°C) 1x Mode (0°C to 95°C) 2x Mode (0°C to 95°C) 4x Mode (0°C to 95°C) REF@260ns REF@160ns REF@110ns REF@260ns REF@160ns REF@110ns 97 0. = μs = s 5μ 1. Rt E FI 95 FI REF@110ns s s 5μ = 1. Rt E FI 95 = μs 0. FI Rt E REF@260ns REF@160ns s 5μ REF@110ns REF@110ns = μs 5μ 97 0. = s FI 9μ 5μ = FI 5μ s Rt E 95 1. = 97 FI REF@110ns REF@160ns 5μ REF@260ns REF@110ns 97 REF@110ns = FI μs 5μ 97 0. = FI 5μ s Rt E = s 97 REF@160ns 5μ REF@260ns REF@110ns 97 REF@110ns FI μs = s 5μ 1. Rt E 95 s = Rt E 0. FI REF@110ns 97 μs 95 1. = FI Rt E s Rt E FI 9μ 3. = 5μ s 9μ 3. 97 REF@110ns 0. REF@160ns FI 5μ 97 0. = Rt E FI Rt E s Rt E REF@110ns Rt E FI FI = = 1. 1. 95 95 μs μs = FI REF@110ns Rt E = FI Rt E = 0. REF@160ns s Rt E Rt E FI FI = Rt E 0. FI = FI Rt E 5μ 1. Rt E 95 FI μs = 0. 97 FI μs 95 1. s 8μ 7. REF@110ns REF@260ns REF@160ns REF@110ns REF@260ns REF@160ns REF@110ns 4Gb: x4, x8, x16 DDR4 SDRAM Fine Granularity Refresh Mode Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. = s Rt E 95 1. FI Rt E s 9μ 3. REF@110ns REF@160ns Rt E FI REF@110ns Rt E REF@110ns = = 3. 9μ s Rt E FI = 1. 95 μs 0. REF@160ns = 139 REF@260ns s Rt E FI = 0. Rt E Rt E FI = 1. 95 μs 0. 97 FI Rt E s Rt E 3. REF@110ns REF@160ns μs Rt E FI REF@110ns s Rt E FI 95 1. = Rt E FI REF@110ns = = 3. 9μ s Rt E FI = 1. 95 Rt E μs FI 0. 97 REF@160ns = 7. 8μ s Rt E FI = 0. 97 FI REF@110ns Rt E FI = 1. 95 μs 97 REF@110ns REF@160ns Rt E 5μ = Rt E 3. FI 9μ = s 0. Rt E 97 95 1. = FI Rt E s 9μ 3. = FI REF@110ns Rt E 5μ s 1x Mode (0°C to 85°C) μs PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Figure 79: 4Gb with Fine Granularity Refresh Mode Example 4Gb: x4, x8, x16 DDR4 SDRAM Fine Granularity Refresh Mode Changing Refresh Rate If the refresh rate is changed by either MRS or OTF. New tREFI and tRFC parameters will be applied from the moment of the rate change. When the REF1x command is issued to the DRAM, tREF1 and tRFC1 are applied from the time that the command was issued; when the REF2x command is issued, tREF2 and tRFC2 should be satisfied. Figure 80: OTF REFRESH Command Timing CK_c CK_t Command DES REF1 DES DES tRFC1 DES Valid Valid REF2 DES tRFC2 (MIN) tREFI1 DES Valid DES REF2 DES (MIN) tREFI2 Don’t Care The following conditions must be satisfied before the refresh rate can be changed. Otherwise, data retention cannot be guaranteed. • In the fixed 2x refresh rate mode or the OTF 1x/2x refresh mode, an even number of REF2x commands must be issued because the last change of the refresh rate mode with an MRS command before the refresh rate can be changed by another MRS command. • In the OTF1x/2x refresh rate mode, an even number of REF2x commands must be issued between any two REF1x commands. • In the fixed 4x refresh rate mode or the OTF 1x/4x refresh mode, a multiple-of-four number of REF4x commands must be issued because the last change of the refresh rate with an MRS command before the refresh rate can be changed by another MRS command. • In the OTF1x/4x refresh rate mode, a multiple-of-four number of REF4x commands must be issued between any two REF1x commands. There are no special restrictions for the fixed 1x refresh rate mode. Switching between fixed and OTF modes keeping the same rate is not regarded as a refresh rate change. Usage with TCR Mode If the temperature controlled refresh mode is enabled, only the normal mode (fixed 1x mode, MR3[8:6] = 000) is allowed. If any other refresh mode than the normal mode is selected, the temperature controlled refresh mode must be disabled. Self Refresh Entry and Exit The device can enter self refresh mode anytime in 1x, 2x, and 4x mode without any restriction on the number of REFRESH commands that have been issued during the mode before the self refresh entry. However, upon self refresh exit, extra REFRESH command(s) may be required, depending on the condition of the self refresh entry. The conditions and requirements for the extra REFRESH command(s) are defined as follows: • In the fixed 2x refresh rate mode or the enable-OTF 1x/2x refresh rate mode, it is recommended there be an even number of REF2x commands before entry into self refresh after the last self refresh exit, REF1x command, or MRS command that set the PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 140 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Fine Granularity Refresh Mode refresh mode. If this condition is met, no additional REFRESH commands are required upon self refresh exit. In the case that this condition is not met, either one extra REF1x command or two extra REF2x commands must be issued upon self refresh exit. These extra REFRESH commands are not counted toward the computation of the average refresh interval (tREFI). • In the fixed 4x refresh rate mode or the enable-OTF 1x/4x refresh rate mode, it is recommended there be a multiple-of-four number of REF4x commands before entry into self refresh after the last self refresh exit, REF1x command, or MRS command that set the refresh mode. If this condition is met, no additional refresh commands are required upon self refresh exit. When this condition is not met, either one extra REF1x command or four extra REF4x commands must be issued upon self refresh exit. These extra REFRESH commands are not counted toward the computation of the average refresh interval (tREFI). There are no special restrictions on the fixed 1x refresh rate mode. This section does not change the requirement regarding postponed REFRESH commands. The requirement for the additional REFRESH command(s) described above is independent of the requirement for the postponed REFRESH commands. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 141 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM SELF REFRESH Operation SELF REFRESH Operation The SELF REFRESH command can be used to retain data in the device, even if the rest of the system is powered down. When in self refresh mode, the device retains data without external clocking. The device has a built-in timer to accommodate SELF REFRESH operation. The SELF REFRESH command is defined by having CS_n, RAS_n, CAS_n, and CKE held LOW with WE_n and ACT_n HIGH at the rising edge of the clock. Before issuing the SELF REFRESH ENTRY command, the device must be idle with all banks in the precharge state and tRP satisfied. Idle state is defined as: All banks are closed (tRP, tDAL, and so on, satisfied), no data bursts are in progress, CKE is HIGH, and all timings from previous operations are satisfied (tMRD, tMOD, tRFC, tZQinit, tZQoper, tZQCS, and so on). After the SELF REFRESH ENTRY command is registered, CKE must be held LOW to keep the device in self refresh mode. The DRAM automatically disables ODT termination, regardless of the ODT pin, when it enters self refresh mode and automatically enables ODT upon exiting self refresh. During normal operation (DLL_on), the DLL is automatically disabled upon entering self refresh and is automatically enabled (including a DLL reset) upon exiting self refresh. When the device has entered self refresh mode, all of the external control signals, except CKE and RESET_n, are “Don’t Care.” For proper SELF REFRESH operation, all power supply and reference pins (VDD, V DDQ, V SS, V SSQ, V PP, and V REFCA) must be at valid levels. The DRAM internal V REFDQ generator circuitry may remain on or be turned off depending on the MRx bit Y setting. If the internal V REFDQ circuit is on in self refresh, the first WRITE operation or first write-leveling activity may occur after tXS time after self refresh exit. If the DRAM internal V REFDQ circuitry is turned off in self refresh, it ensures that the V REFDQ generator circuitry is powered up and stable within the tXSDLL period when the DRAM exits the self refresh state. The first WRITE operation or first write-leveling activity may not occur earlier than tXSDLL after exiting self refresh. The device initiates a minimum of one REFRESH command internally within the tCKE period once it enters self refresh mode. The clock is internally disabled during a SELF REFRESH operation to save power. The minimum time that the device must remain in self refresh mode is tCKESR/ tCKESR_PAR. The user may change the external clock frequency or halt the external clock tCKSRE/tCKSRE_PAR after self refresh entry is registered; however, the clock must be restarted and tCKSRX must be stable before the device can exit SELF REFRESH operation. The procedure for exiting self refresh requires a sequence of events. First, the clock must be stable prior to CKE going back HIGH. Once a SELF REFRESH EXIT command (SRX, combination of CKE going HIGH and DESELECT on the command bus) is registered, the following timing delay must be satisfied: Commands that do not require locked DLL: • tXS = ACT, PRE, PREA, REF, SRE, and PDE. • tXS_FAST = ZQCL, ZQCS, and MRS commands. For an MRS command, only DRAM CL, WR/RTP register, and DLL reset in MR0; R TT(NOM) register in MR1; the CWL and RTT(WR) registers in MR2; and gear-down mode register in MR3; WRITE and READ preamble registers in MR4; RTT(PARK) register in MR5; tCCD_L/tDLLK and V REFDQ calibration value registers in MR6 may be accessed provided the DRAM is not in per-DRAM mode. Access to other DRAM mode registers must satisfy tXS timing. WRITE commands (WR, WRS4, WRS8, WRA, WRAS4, and WRAS8) that require synchronous ODT and dynamic ODT controlled by the WRITE command require a locked DLL. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 142 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM SELF REFRESH Operation Commands that require locked DLL in the normal operating range: • tXSDLL – RD, RDS4, RDS8, RDA, RDAS4, and RDAS8 (unlike DDR3, WR, WRS4, WRS8, WRA, WRAS4, and WRAS8 because synchronous ODT is required). Depending on the system environment and the amount of time spent in self refresh, ZQ CALIBRATION commands may be required to compensate for the voltage and temperature drift described in the ZQ CALIBRATION Commands section. To issue ZQ CALIBRATION commands, applicable timing requirements must be satisfied (see the ZQ Calibration Timing figure). CKE must remain HIGH for the entire self refresh exit period tXSDLL for proper operation except for self refresh re-entry. Upon exit from self refresh, the device can be put back into self refresh mode or power-down mode after waiting at least tXS period and issuing one REFRESH command (refresh period of tRFC). The DESELECT command must be registered on each positive clock edge during the self refresh exit interval tXS. ODT must be turned off during tXSDLL. The use of self refresh mode introduces the possibility that an internally timed refresh event can be missed when CKE is raised for exit from self refresh mode. Upon exit from self refresh, the device requires a minimum of one extra REFRESH command before it is put back into self refresh mode. Figure 81: Self Refresh Entry/Exit Timing T0 T1 Ta0 Tb0 Tc0 Td0 Td1 Te0 Tf0 Tg0 Valid Valid Valid CK_c CK_t tCKSRX tCKSRE/tCKSRE_PAR tIS tCPDED CKE tCKESR/tCKESR_PAR Valid ODT tXS_FAST Command DES SRE SRX DES ADDR Valid 1 Valid 2 Valid 3 Valid Valid Valid tXS tRP tXSDLL Enter Self Refresh Exit Self Refresh Don’t Care Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Time Break 1. Only MRS (limited to those described in the SELF REFRESH Operation section), ZQCS, or ZQCL commands are allowed. 2. Valid commands not requiring a locked DLL. 3. Valid commands requiring a locked DLL. 143 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM SELF REFRESH Operation Re se rv ed Fo rF ig ur e Figure 82: Self Refresh Entry/Exit Timing with CAL Mode Notes: 1. tCAL = 3nCK, tCPDED = 4nCK, tCKSRE/tCKSRE_PAR = 8nCK, tCKSRX = 8nCK, tXS_FAST = tREFC4 (MIN) + 10ns. 2. CS_n = HIGH, ACT_n = "Don't Care," RAS_n/A16 = "Don't Care," CAS_n/A15 = "Don't Care," WE_n/A14 = "Don't Care." 3. Only MRS (limited to those described in the SELF REFRESH Operations section), ZQCS, or ZQCL commands are allowed. Self Refresh Abort The exit timing from self refresh exit to the first valid command not requiring a locked DLL is tXS. The value of tXS is (tRFC + 10ns). This delay allows any refreshes started by the device time to complete. tRFC continues to grow with higher density devices, so tXS will grow as well. An MRS bit enables the self refresh abort mode. If the bit is disabled, the controller uses tXS timings (location MR4, bit 9). If the bit is enabled, the device aborts any ongoing refresh and does not increment the refresh counter. The controller can issue a valid command not requiring a locked DLL after a delay of tXS_ABORT. Upon exit from self refresh, the device requires a minimum of one extra REFRESH command before it is put back into self refresh mode. This requirement remains the same irrespective of the setting of the MRS bit for self refresh abort. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 144 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM SELF REFRESH Operation Figure 83: Self Refresh Abort T0 T1 Ta0 Tb0 Tc0 Td0 Td1 Te0 Tf0 Tg0 Valid Valid Valid CK_c CK_t tCKSRX tCKSRE/tCKSRE_PAR tIS tCPDED CKE tCKESR/tCKESR_PAR ODT Valid tXS_FAST Command DES SRE SRX DES ADDR Valid 1 Valid 2 Valid 3 Valid Valid Valid tXS_ABORT tRP tXSDLL Enter Self Refresh Exit Self Refresh Don’t Care Notes: Time Break 1. Only MRS (limited to those described in the SELF REFRESH Operation section), ZQCS, or ZQCL commands are allowed. 2. Valid commands not requiring a locked DLL with self refresh abort mode enabled in the mode register. 3. Valid commands requiring a locked DLL. Self Refresh Exit with NOP Command Exiting self refresh mode using the NO OPERATION command (NOP) is allowed under a specific system application. This special use of NOP allows for a common command/ address bus between active DRAM devices and DRAM(s) in maximum power saving mode. Self refresh mode may exit with NOP commands provided: • The device entered self refresh mode with CA parity and CAL disabled. • tMPX_S and tMPX_LH are satisfied. • NOP commands are only issued during tMPX_LH window. No other command is allowed during the tMPX_LH window after an SELF REFRESH EXIT (SRX) command is issued. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 145 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM SELF REFRESH Operation Re se rv ed Fo rF ig ur e Figure 84: Self Refresh Exit with NOP Command PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 146 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Power-Down Mode Power-Down Mode Power-down is synchronously entered when CKE is registered LOW (along with a DESELECT command). CKE is not allowed to go LOW when the following operations are in progress: MRS command, MPR operations, ZQCAL operations, DLL locking, or READ/ WRITE operations. CKE is allowed to go LOW while any other operations, such as ROW ACTIVATION, PRECHARGE or auto precharge, or REFRESH, are in progress, but the power-down IDD specification will not be applied until those operations are complete. The timing diagrams that follow illustrate power-down entry and exit. For the fastest power-down exit timing, the DLL should be in a locked state when power-down is entered. If the DLL is not locked during power-down entry, the DLL must be reset after exiting power-down mode for proper READ operation and synchronous ODT operation. DRAM design provides all AC and DC timing and voltage specification as well as proper DLL operation with any CKE intensive operations as long as the controller complies with DRAM specifications. During power-down, if all banks are closed after any in-progress commands are completed, the device will be in precharge power-down mode; if any bank is open after inprogress commands are completed, the device will be in active power-down mode. Entering power-down deactivates the input and output buffers, excluding CK, CKE, and RESET_n. In power-down mode, DRAM ODT input buffer deactivation is based on MRx bit Y. If it is configured to 0b, the ODT input buffer remains on and the ODT input signal must be at valid logic level. If it is configured to 1b, the ODT input buffer is deactivated and the DRAM ODT input signal may be floating and the device does not provide RTT(NOM) termination. Note that the device continues to provide RTT(Park) termination if it is enabled in the mode register MRa bit B. To protect internal delay on the CKE line to block the input signals, multiple DES commands are needed during the CKE switch off and on cycle(s); this timing period is defined as tCPDED. CKE LOW will result in deactivation of command and address receivers after tCPDED has expired. Table 49: Power-Down Entry Definitions DRAM Status DLL PowerDown Exit Active (a bank or more open) On Fast tXP to any valid command. Precharged (all banks precharged) On Fast tXP to any valid command. Relevant Parameters The DLL is kept enabled during precharge power-down or active power-down. In power-down mode, CKE is LOW, RESET_n is HIGH, and a stable clock signal must be maintained at the inputs of the device. ODT should be in a valid state, but all other input signals are "Don't Care." (If RESET_n goes LOW during power-down, the device will be out of power-down mode and in the reset state.) CKE LOW must be maintained until tCKE has been satisfied. Power-down duration is limited by 9 × tREFI. The power-down state is synchronously exited when CKE is registered HIGH (along with DES command). CKE HIGH must be maintained until tCKE has been satisfied. The ODT input signal must be at a valid level when the device exits from power-down mode, independent of MRx bit Y if R TT(NOM) is enabled in the mode register. If RTT(NOM) is disabled, the ODT input signal may remain floating. A valid, executable command can be PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 147 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Power-Down Mode applied with power-down exit latency, tXP, and/or tXPDLL after CKE goes HIGH. Powerdown exit latency is defined in the AC Specifications table. Figure 85: Active Power-Down Entry and Exit T0 T1 T2 Valid DES DES Ta0 Ta1 Tb0 Tb1 Tc0 CK_c CK_t Command DES DES DES Valid Valid Valid tPD tIS tIH CKE tIH tCKE tIS ODT (ODT buffer enabled - MR5 [5] = 0)2 tIS ODT (ODT buffer disbled - MR5 [5] = Address 1)3 Valid Valid tCPDED tXP Enter power-down mode Exit power-down mode Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. Valid commands at T0 are ACT, DES, or PRE with one bank remaining open after completion of the PRECHARGE command. 2. ODT pin driven to a valid state; MR5[5] = 0 (normal setting). 3. ODT pin driven to a valid state; MR5[5] = 1. 148 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Power-Down Mode Figure 86: Power-Down Entry After Read and Read with Auto Precharge CK_c T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Ta8 Tb0 Tb1 RD or RDA DES DES DES DES DES DES DES DES DES DES DES Valid CK_t Command tIS tCPDED Valid CKE Valid Valid Address RL = AL + CL tPD DQS_t, DQS_c DQ BL8 DI b DI b+1 DI b+2 DI b+3 DQ BC4 DI n DI n+1 DI n+2 DI n+3 DI b+4 DI b+5 DI b+6 DI b+7 tRDPDEN Power-Down entry Transitioning Data Note: Don’t Care Time Break 1. DI n (or b) = data-in from column n (or b). Figure 87: Power-Down Entry After Write and Write with Auto Precharge CK_c T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Tb0 WRITE DES DES DES DES DES DES DES DES DES DES Tb1 Tb2 Tc0 Tc1 DES DES Valid CK_t Command DES tIS tCPDED Valid CKE Address Bank, Col n Valid A10 WL = AL + CWL tPD WR DQS_t, DQS_c DQ BL8 DI b DI b+1 DI b+2 DI b+3 DQ BC4 DI n DI n+1 DI n+2 DI n+3 DI b+4 DI b+5 DI b+6 DI b+7 Start internal precharge tWRAPDEN Power-Down entry Transitioning Data Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 7LPH%UHDN 'RQ¶W&DUH 1. DI n (or b) = data-in from column n (or b). 2. Valid commands at T0 are ACT, DES, or PRE with one bank remaining open after completion of the PRECHARGE command. 149 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Power-Down Mode Figure 88: Power-Down Entry After Write CK_c T0 T1 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Tb0 WRITE DES DES DES DES DES DES DES DES DES DES Tb1 Tb2 Tc0 Tc1 DES DES Valid CK_t Command DES tIS tCPDED Valid CKE Address Bank, Col n Valid A10 WL = AL + CWL tPD tWR DQS_t, DQS_c DQ BL8 DI b DI b+1 DI b+2 DI b+3 DQ BC4 DI n DI n+1 DI n+2 DI n+3 DI b+4 DI b+5 DI b+6 DI b+7 tWRPDEN Power-Down entry Transitioning Data Note: Time Break Don’t Care 1. DI n (or b) = data-in from column n (or b). Figure 89: Precharge Power-Down Entry and Exit T0 T1 T2 Ta0 Ta1 Tb0 Tb1 Tc0 DES DES DES DES DES DES Valid Valid Valid CK_c CK_t Command tCPDED tCKE tIS tIH CKE tIS tPD tXP Exit power-down mode Enter power-down mode Time Break PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 150 Don’t Care Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Power-Down Mode Figure 90: REFRESH Command to Power-Down Entry T0 T1 T2 Ta0 Tb0 Tb1 REF DES DES DES DES CK_c CK_t Command Address Valid tCPDED tIS tPD tCKE CKE Valid tREFPDEN Time Break Don’t Care Figure 91: Active Command to Power-Down Entry T0 T1 T2 Ta0 Tb0 Tb1 ACT DES DES DES DES CK_c CK_t Command Address Valid tCPDED tIS tPD tCKE CKE Valid tACTPDEN Time Break PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 151 Don’t Care Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Power-Down Mode Figure 92: PRECHARGE/PRECHARGE ALL Command to Power-Down Entry T0 T1 T2 Ta0 Tb0 Tb1 PRE or PREA DES DES DES Valid CK_c CK_t Command Address Valid tCPDED tIS tPD tCKE CKE tPREPDEN Time Break Don’t Care Figure 93: MRS Command to Power-Down Entry T0 T1 Ta0 Ta1 Command MRS DES DES DES Address Valid Tb0 Tb1 CK_c CK_t DES tCPDED tIS tPD tCKE CKE Valid tMRSPDEN Time Break Don’t Care Power-Down Clarifications – Case 1 When CKE is registered LOW for power-down entry, tPD (MIN) must be satisfied before CKE can be registered HIGH for power-down exit. The minimum value of parameter tPD (MIN) is equal to the minimum value of parameter tCKE (MIN) as shown in the Timing Parameters by Speed Bin table. A detailed example of Case 1 follows. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 152 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Power-Down Mode Figure 94: Power-Down Entry/Exit Clarifications – Case 1 T0 T1 T2 Valid DES DES Ta0 Ta1 Tb0 Tb1 Tb2 CK_c CK_t Command DES DES DES DES tPD tPD tIH tIS tIS CKE tIS tIH Address tCKE Valid tCPDED tCPDED Enter power-down mode Exit power-down mode Enter power-down mode Time Break Don’t Care Power-Down Entry, Exit Timing with CAL Command/Address latency is used and additional timing restrictions are required when entering power-down, as noted in the following figures. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 153 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Power-Down Mode Re se rv ed Fo rF ig ur e Figure 95: Active Power-Down Entry and Exit Timing with CAL PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 154 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Power-Down Mode Re se rv ed Fo rF ig ur e Figure 96: REFRESH Command to Power-Down Entry with CAL PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 155 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM ODT Input Buffer Disable Mode for Power-Down ODT Input Buffer Disable Mode for Power-Down ODT input buffer disable mode, when enabled via MR5[5], will prevent the device from providing RTT(NOM) termination during power-down for additional power savings. The internal delay on the CKE path to disable the ODT buffer and block the sampled output must be accounted for; therefore, ODT must be continuously driven to a valid level, either LOW or HIGH, when entering power-down. However, after tCPDED (MIN) has been satisfied, the ODT signal may float. When ODT input buffer disable mode is enabled, RTT(NOM) termination corresponding to sampled ODT after CKE is first registered LOW (and tANPD before that) may not be provided. tANPD is equal to (WL - 1) and is counted backward from PDE, with CKE registered LOW. Figure 97: ODT Power-Down Entry with ODT Buffer Disable Mode diff_CK CKE tDODTLoff tCPDED +1 (MIN) Floating ODT tADC DRAM_RTT_sync (DLL enabled) CA parity disabled (MIN) RTT(NOM) RTT(Park) tCPDED DODTLoff tADC DRAM_RTT_sync (DLL enabled) CA parity enabled RTT(NOM) DRAM_RTT_async (DLL disabled) RTT(NOM) (MIN) RTT(Park) tCPDED DODTLoff (MIN) + tADC (MAX) + PL RTT(Park) tAONAS (MIN) tCPDED PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN (MIN) + tADC (MAX) 156 (MIN) + tAOFAS (MAX) Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM ODT Input Buffer Disable Mode for Power-Down Figure 98: ODT Power-Down Exit with ODT Buffer Disable Mode diff_CK CKE ODT_A (DLL enabled) Floating tADC tXP RTT(NOM) RTT(Park) DRAM_RTT_A DODTLon ODT_B (DLL disabled) (MAX) tADC (MIN) Floating tXP DRAM_RTT_B RTT(Park) tAONAS RTT(NOM) (MIN) tAOFAS PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN (MAX) 157 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM CRC Write Data Feature CRC Write Data Feature CRC Write Data The CRC write data feature takes the CRC generated data from the DRAM controller and compares it to the internally CRC generated data and determines whether the two match (no CRC error) or do not match (CRC error). Figure 99: CRC Write Data Operation DRAM DRAM Controller Data Data CRC engine CRC engine CRC Code Data CRC Code CRC Code Compare CRC WRITE CRC DATA Operation A DRAM controller generates a CRC checksum using a 72-bit CRC tree and forms the write data frames, as shown in the following CRC data mapping tables for the x4, x8, and x16 configurations. A x4 device has a CRC tree with 32 input data bits used, and the remaining upper 40 bits D[71:32] being 1s. A x8 device has a CRC tree with 64 input data bits used, and the remaining upper 8 bits dependant upon whether DM_n/DBI_n is used (1s are sent when not used). A x16 device has two identical CRC trees each, one for the lower byte and one for the upper byte, with 64 input data bits used by each, and the remaining upper 8 bits on each byte dependant upon whether DM_n/DBI_n is used (1s are sent when not used). For a x8 and x16 DRAMs, the DRAM memory controller must send 1s in transfer 9 location whether or not DM_n/DBI_n is used. The DRAM checks for an error in a received code word D[71:0] by comparing the received checksum against the computed checksum and reports errors using the ALERT_n signal if there is a mismatch. The DRAM can write data to the DRAM core without waiting for the CRC check for full writes when DM is disabled. If bad data is written to the DRAM core, the DRAM memory controller will try to overwrite the bad data with good data; this means the DRAM controller is responsible for data coherency when DM is disabled. However, in the case where both CRC and DM are enabled via PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 158 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM CRC Write Data Feature MRS (that is, persistent mode), the DRAM will not write bad data to the core when a CRC error is detected. DBI_n and CRC Both Enabled The DRAM computes the CRC for received written data D[71:0]. Data is not inverted back based on DBI before it is used for computing CRC. The data is inverted back based on DBI before it is written to the DRAM core. DM_n and CRC Both Enabled When both DM and write CRC are enabled in the DRAM mode register, the DRAM calculates CRC before sending the write data into the array. If there is a CRC error, the DRAM blocks the WRITE operation and discards the data. The Nonconsecutive WRITE (BL8/BC4-OTF) with 2tCK Preamble and Write CRC in Same or Different Bank Group and the WRITE (BL8/BC4-OTF/Fixed) with 1tCK Preamble and Write CRC in Same or Different BankGroup figures in the WRITE Operation section show timing differences when DM is enabled. DM_n and DBI_n Conflict During Writes with CRC Enabled Both write DBI_n and DM_n can not be enabled at the same time; read DBI_n and DM_n can be enabled at the same time. CRC and Write Preamble Restrictions When write CRC is enabled: • And 1tCK WRITE preamble mode is enabled, a tCCD_S or tCCD_L of 4 clocks is not allowed. • And 2tCK WRITE preamble mode is enabled, a tCCD_S or tCCD_L of 6 clocks is not allowed. CRC Simultaneous Operation Restrictions When write CRC is enabled, neither MPR writes nor per-DRAM mode is allowed. CRC Polynomial The CRC polynomial used by DDR4 is the ATM-8 HEC, X8 + X2 + X1 + 1. A combinatorial logic block implementation of this 8-bit CRC for 72 bits of data includes 272 two-input XOR gates contained in eight 6-XOR-gate-deep trees. The CRC polynomial and combinatorial logic used by DDR4 is the same as used on GDDR5. The error coverage from the DDR4 polynomial used is shown in the following table. Table 50: CRC Error Detection Coverage PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Error Type Detection Capability Random single-bit errors 100% Random double-bit errors 100% 159 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM CRC Write Data Feature Table 50: CRC Error Detection Coverage (Continued) Error Type Detection Capability Random odd count errors 100% Random multibit UI vertical column error detection excluding DBI bits 100% CRC Combinatorial Logic Equations module CRC8_D72; // polynomial: (0 1 2 8) // data width: 72 // convention: the first serial data bit is D[71] //initial condition all 0 implied // "^" = XOR function [7:0] nextCRC8_D72; input [71:0] Data; input [71:0] D; reg [7:0] CRC; begin D = Data; CRC[0] = D[69]^D[68]^D[67]^D[66]^D[64]^D[63]^D[60]^D[56]^D[54]^D[53]^D[52]^D[50]^D[49 ]^D[48]^D[45]^D[43]^D[40]^D[39]^D[35]^D[34]^D[31]^D[30]^D[28]^D[23]^D[21]^D[1 9]^D[18]^D[16]^D[14]^D[12]^D[8]^D[7]^D[6]^D[0] ; CRC[1] = D[70]^D[66]^D[65]^D[63]^D[61]^D[60]^D[57]^D[56]^D[55]^D[52]^D[51]^D[48]^D[46 ]^D[45]^D[44]^D[43]^D[41]^D[39]^D[36]^D[34]^D[32]^D[30]^D[29]^D[28]^D[24]^D[2 3]^D[22]^D[21]^D[20]^D[18]^D[17]^D[16]^D[15]^D[14]^D[13]^D[12]^D[9]^D[6]^D[1 ]^D[0]; CRC[2] = D[71]^D[69]^D[68]^D[63]^D[62]^D[61]^D[60]^D[58]^D[57]^D[54]^D[50]^D[48]^D[47 ]^D[46]^D[44]^D[43]^D[42]^D[39]^D[37]^D[34]^D[33]^D[29]^D[28]^D[25]^D[24]^D[2 2]^D[17]^D[15]^D[13]^D[12]^D[10]^D[8]^D[6]^D[2]^D[1]^D[0]; CRC[3] = D[70]^D[69]^D[64]^D[63]^D[62]^D[61]^D[59]^D[58]^D[55]^D[51]^D[49]^D[48]^D[47 ]^D[45]^D[44]^D[43]^D[40]^D[38]^D[35]^D[34]^D[30]^D[29]^D[26]^D[25]^D[23]^D[1 8]^D[16]^D[14]^D[13]^D[11]^D[9]^D[7]^D[3]^D[2]^D[1]; CRC[4] = D[71]^D[70]^D[65]^D[64]^D[63]^D[62]^D[60]^D[59]^D[56]^D[52]^D[50]^D[49]^D[48 ]^D[46]^D[45]^D[44]^D[41]^D[39]^D[36]^D[35]^D[31]^D[30]^D[27]^D[26]^D[24]^D[1 9]^D[17]^D[15]^D[14]^D[12]^D[10]^D[8]^D[4]^D[3]^D[2]; CRC[5] = D[71]^D[66]^D[65]^D[64]^D[63]^D[61]^D[60]^D[57]^D[53]^D[51]^D[50]^D[49]^D[47 ]^D[46]^D[45]^D[42]^D[40]^D[37]^D[36]^D[32]^D[31]^D[28]^D[27]^D[25]^D[20]^D[1 8]^D[16]^D[15]^D[13]^D[11]^D[9]^D[5]^D[4]^D[3]; PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 160 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM CRC Write Data Feature CRC[6] = D[67]^D[66]^D[65]^D[64]^D[62]^D[61]^D[58]^D[54]^D[52]^D[51]^D[50]^D[48]^D[47 ]^D[46]^D[43]^D[41]^D[38]^D[37]^D[33]^D[32]^D[29]^D[28]^D[26]^D[21]^D[19]^D[1 7]^D[16]^D[14]^D[12]^D[10]^D[6]^D[5]^D[4]; CRC[7] = D[68]^D[67]^D[66]^D[65]^D[63]^D[62]^D[59]^D[55]^D[53]^D[52]^D[51]^D[49]^D[48 ]^D[47]^D[44]^D[42]^D[39]^D[38]^D[34]^D[33]^D[30]^D[29]^D[27]^D[22]^D[20]^D[1 8]^D[17]^D[15]^D[13]^D[11]^D[7]^D[6]^D[5]; nextCRC8_D72 = CRC; Burst Ordering for BL8 DDR4 supports fixed WRITE burst ordering [A2:A1:A0 = 0:0:0] when write CRC is enabled in BL8 (fixed). CRC Data Bit Mapping Table 51: CRC Data Mapping for x4 Devices, BL8 Transfer Function 0 1 2 3 4 5 6 7 8 9 DQ0 D0 D1 D2 D3 D4 D5 D6 D7 CRC0 CRC4 DQ1 D8 D9 D10 D11 D12 D13 D14 D15 CRC1 CRC5 DQ2 D16 D17 D18 D19 D20 D21 D22 D23 CRC2 CRC6 DQ3 D24 D25 D26 D27 D28 D29 D30 D31 CRC3 CRC7 6 7 8 9 Table 52: CRC Data Mapping for x8 Devices, BL8 Transfer Function 0 1 DQ0 D0 D1 D2 D3 D4 D5 D6 D7 CRC0 1 DQ1 D8 D9 D10 D11 D12 D13 D14 D15 CRC1 1 DQ2 D16 D17 D18 D19 D20 D21 D22 D23 CRC2 1 DQ3 D24 D25 D26 D27 D28 D29 D30 D31 CRC3 1 DQ4 D32 D33 D34 D35 D36 D37 D38 D39 CRC4 1 DQ5 D40 D41 D42 D43 D44 D45 D46 D47 CRC5 1 DQ6 D48 D49 D50 D51 D52 D53 D54 D55 CRC6 1 DQ7 D56 D57 D58 D59 D60 D61 D62 D63 CRC7 1 DM_n/ DBI_n D64 D65 D66 D67 D68 D69 D70 D71 1 1 2 3 4 5 A x16 device is treated as two x8 devices; a x16 device will have two identical CRC trees implemented. CRC[7:0] covers data bits D[71:0], and CRC[15:8] covers data bits D[143:72]. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 161 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM CRC Write Data Feature Table 53: CRC Data Mapping for x16 Devices, BL8 Transfer Function 0 1 2 3 4 5 6 7 8 9 DQ0 D0 D1 D2 D3 D4 D5 D6 D7 CRC0 1 DQ1 D8 D9 D10 D11 D12 D13 D14 D15 CRC1 1 DQ2 D16 D17 D18 D19 D20 D21 D22 D23 CRC2 1 DQ3 D24 D25 D26 D27 D28 D29 D30 D31 CRC3 1 DQ4 D32 D33 D34 D35 D36 D37 D38 D39 CRC4 1 DQ5 D40 D41 D42 D43 D44 D45 D46 D47 CRC5 1 DQ6 D48 D49 D50 D51 D52 D53 D54 D55 CRC6 1 DQ7 D56 D57 D58 D59 D60 D61 D62 D63 CRC7 1 LDM_n/ LDBI_n D64 D65 D66 D67 D68 D69 D70 D71 1 1 DQ8 D72 D73 D74 D75 D76 D77 D78 D79 CRC8 1 DQ9 D80 D81 D82 D83 D84 D85 D86 D87 CRC9 1 DQ10 D88 D89 D90 D91 D92 D93 D94 D95 CRC10 1 DQ11 D96 D97 D98 D99 D100 D101 D102 D103 CRC11 1 DQ12 D104 D105 D106 D107 D108 D109 D110 D111 CRC12 1 DQ13 D112 D113 D114 D115 D116 D117 D118 D119 CRC13 1 DQ14 D120 D121 D122 D123 D124 D125 D126 D127 CRC14 1 DQ15 D128 D129 D130 D131 D132 D133 D134 D135 CRC15 1 UDM_n/ UDBI_n D136 D137 D138 D139 D140 D141 D142 D143 1 1 CRC Enabled With BC4 If CRC and BC4 are both enabled, then address bit A2 is used to transfer critical data first for BC4 writes. CRC with BC4 Data Bit Mapping For a x4 device, the CRC tree inputs are 16 data bits, and the inputs for the remaining bits are 1. When A2 = 1, data bits D[7:4] are used as inputs for D[3:0], D[15:12] are used as inputs to D[11:8], and so forth, for the CRC tree. Table 54: CRC Data Mapping for x4 Devices, BC4 Transfer Function 0 1 2 3 DQ0 D0 D1 D2 D3 DQ1 D8 D9 D10 DQ2 D16 D17 D18 4 5 6 7 8 9 1 1 1 1 CRC0 CRC4 D11 1 1 1 1 CRC1 CRC5 D19 1 1 1 1 CRC2 CRC6 A2 = 0 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 162 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM CRC Write Data Feature Table 54: CRC Data Mapping for x4 Devices, BC4 (Continued) Transfer Function 0 1 2 3 4 5 6 7 8 9 DQ3 D24 D25 D26 D27 1 1 1 1 CRC3 CRC7 A2 = 1 DQ0 D4 D5 D6 D7 1 1 1 1 CRC0 CRC4 DQ1 D12 D13 D14 D15 1 1 1 1 CRC1 CRC5 DQ2 D20 D21 D22 D23 1 1 1 1 CRC2 CRC6 DQ3 D28 D29 D30 D31 1 1 1 1 CRC3 CRC7 For a x8 device, the CRC tree inputs are 36 data bits. When A2 = 0, the input bits D[67:64]) are used if DBI_n or DM_n functions are enabled; if DBI_n and DM_n are disabled, then D[67:64]) are 1. When A2 = 1, data bits D[7:4] are used as inputs for D[3:0], D[15:12] are used as inputs to D[11:8], and so forth, for the CRC tree. The input bits D[71:68]) are used if DBI_n or DM_n functions are enabled; if DBI_n and DM_n are disabled, then D[71:68]) are 1. Table 55: CRC Data Mapping for x8 Devices, BC4 Transfer Function 0 1 2 3 DQ0 D0 D1 D2 D3 DQ1 D8 D9 D10 DQ2 D16 D17 DQ3 D24 DQ4 D32 DQ5 4 5 6 7 8 9 1 1 1 1 CRC0 1 D11 1 1 1 1 CRC1 1 D18 D19 1 1 1 1 CRC2 1 D25 D26 D27 1 1 1 1 CRC3 1 D33 D34 D35 1 1 1 1 CRC4 1 D40 D41 D42 D43 1 1 1 1 CRC5 1 DQ6 D48 D49 D50 D51 1 1 1 1 CRC6 1 DQ7 D56 D57 D58 D59 1 1 1 1 CRC7 1 DM_n/DBI_n D64 D65 D66 D67 1 1 1 1 1 1 A2 = 0 A2 = 1 DQ0 D4 D5 D6 D7 1 1 1 1 CRC0 1 DQ1 D12 D13 D14 D15 1 1 1 1 CRC1 1 DQ2 D20 D21 D22 D23 1 1 1 1 CRC2 1 DQ3 D28 D29 D30 D31 1 1 1 1 CRC3 1 DQ4 D36 D37 D38 D39 1 1 1 1 CRC4 1 DQ5 D44 D45 D46 D47 1 1 1 1 CRC5 1 DQ6 D52 D53 D54 D55 1 1 1 1 CRC6 1 DQ7 D60 D61 D62 D63 1 1 1 1 CRC7 1 DM_n/DBI_n D68 D69 D70 D71 1 1 1 1 1 1 There are two identical CRC trees for x16 devices, each have CRC tree inputs of 36 bits. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 163 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM CRC Write Data Feature When A2 = 0, input bits D[67:64] are used if DBI_n or DM_n functions are enabled; if DBI_n and DM_n are disabled, then D[67:64] are 1s. The input bits D[139:136] are used if DBI_n or DM_n functions are enabled; if DBI_n and DM_n are disabled, then D[139:136] are 1s. When A2 = 1, data bits D[7:4] are used as inputs for D[3:0], D[15:12] are used as inputs for D[11:8], and so forth, for the CRC tree. Input bits D[71:68] are used if DBI_n or DM_n functions are enabled; if DBI_n and DM_n are disabled, then D[71:68] are 1s. The input bits D[143:140] are used if DBI_n or DM_n functions are enabled; if DBI_n and DM_n are disabled, then D[143:140] are 1s. Table 56: CRC Data Mapping for x16 Devices, BC4 Transfer Function 0 1 2 3 4 5 6 7 8 9 A2 = 0 DQ0 D0 D1 D2 D3 1 1 1 1 CRC0 1 DQ1 D8 D9 D10 D11 1 1 1 1 CRC1 1 DQ2 D16 D17 D18 D19 1 1 1 1 CRC2 1 DQ3 D24 D25 D26 D27 1 1 1 1 CRC3 1 DQ4 D32 D33 D34 D35 1 1 1 1 CRC4 1 DQ5 D40 D41 D42 D43 1 1 1 1 CRC5 1 DQ6 D48 D49 D50 D51 1 1 1 1 CRC6 1 DQ7 D56 D57 D58 D59 1 1 1 1 CRC7 1 LDM_n/LDBI_n D64 D65 D66 D67 1 1 1 1 1 1 DQ8 D72 D73 D74 D75 1 1 1 1 CRC8 1 DQ9 D80 D81 D82 D83 1 1 1 1 CRC9 1 DQ10 D88 D89 D90 D91 1 1 1 1 CRC10 1 DQ11 D96 D97 D98 D99 1 1 1 1 CRC11 1 DQ12 D104 D105 D106 D107 1 1 1 1 CRC12 1 DQ13 D112 D113 D114 D115 1 1 1 1 CRC13 1 DQ14 D120 D121 D122 D123 1 1 1 1 CRC14 1 DQ15 D128 D129 D130 D131 1 1 1 1 CRC15 1 UDM_n/UDBI_n D136 D137 D138 D139 1 1 1 1 1 1 A2 = 1 DQ0 D4 D5 D6 D7 1 1 1 1 CRC0 1 DQ1 D12 D13 D14 D15 1 1 1 1 CRC1 1 DQ2 D20 D21 D22 D23 1 1 1 1 CRC2 1 DQ3 D28 D29 D30 D31 1 1 1 1 CRC3 1 DQ4 D36 D37 D38 D39 1 1 1 1 CRC4 1 DQ5 D44 D45 D46 D47 1 1 1 1 CRC5 1 DQ6 D52 D53 D54 D55 1 1 1 1 CRC6 1 DQ7 D60 D61 D62 D63 1 1 1 1 CRC7 1 LDM_n/LDBI_n D68 D69 D70 D71 1 1 1 1 1 1 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 164 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM CRC Write Data Feature Table 56: CRC Data Mapping for x16 Devices, BC4 (Continued) Transfer Function 0 1 2 3 4 5 6 7 8 9 DQ8 D76 D77 D78 D79 1 1 1 1 CRC8 1 DQ9 D84 D85 D86 D87 1 1 1 1 CRC9 1 DQ10 D92 D93 D94 D95 1 1 1 1 CRC10 1 DQ11 D100 D101 D102 D103 1 1 1 1 CRC11 1 DQ12 D108 D109 D110 D111 1 1 1 1 CRC12 1 DQ13 D116 D117 D118 D119 1 1 1 1 CRC13 1 DQ14 D124 D125 D126 D127 1 1 1 1 CRC14 1 DQ15 D132 D133 D134 D135 1 1 1 1 CRC15 1 UDM_n/UDBI_n D140 D141 D142 D143 1 1 1 1 1 1 CRC Equations for x8 Device in BC4 Mode with A2 = 0 and A2 = 1 The following example is of a CRC tree when x8 is used in BC4 mode (x4 and x16 CRC trees have similar differences). CRC[0], A2=0 = 1^1^D[67]^D[66]^D[64]^1^1^D[56]^1^1^1^D[50]^D[49]^D[48]^1^D[43]^D[40]^1^D[3 5]^D[34]^1^1^1^1^1^D[19]^D[18]^D[16]^1^1^D[8] ^1^1^ D[0] ; CRC[0], A2=1 = 1^1^D[71]^D[70]^D[68]^1^1^D[60]^1^1^1^D[54]^D[53]^D[52]^1^D[47]^D[44]^1^D[3 9]^D[38]^1^1^1^1^1^D[23]^D[22]^D[20]^1^1^D[12]^1^1^D[4] ; CRC[1], A2=0 = 1^D[66]^D[65]^1^1^1^D[57]^D[56]^1^1^D[51]^D[48]^1^1^1^D[43]^D[41]^1^1^D[34 ]^D[32]^1^1^1^D[24]^1^1^1^1^D[18]^D[17]^D[16]^1^1^1^1^D[9] ^1^ D[1]^D[0]; CRC[1], A2=1 = 1^D[70]^D[69]^1^1^1^D[61]^D[60]^1^1^D[55]^D[52]^1^1^1^D[47]^D[45]^1^1^D[38 ]^D[36]^1^1^1^D[28]^1^1^1^1^D[22]^D[21]^D[20]^1^1^1^1^D[13]^1^D[5]^D[4]; CRC[2], A2=0 = 1^1^1^1^1^1^1^D[58]^D[57]^1^D[50]^D[48]^1^1^1^D[43]^D[42]^1^1^D[34]^D[33]^1 ^1^D[25]^D[24]^1^D[17]^1^1^1^D[10]^D[8] ^1^D[2]^D[1]^D[0]; CRC[2], A2=1 = 1^1^1^1^1^1^1^D[62]^D[61]^1^D[54]^D[52]^1^1^1^D[47]^D[46]^1^1^D[38]^D[37]^1 ^1^D[29]^D[28]^1^D[21]^1^1^1^D[14]^D12]^1^D[6]^D[5]^D[4]; CRC[3], A2=0 = 1^1^D[64]^1^1^1^D[59]^D[58]^1^D[51]^D[49]^D[48]^1^1^1^D[43]^D[40]^1^D[35]^ D[34]^1^1^D[26]^D[25]^1^D[18]^D[16]^1^1^D[11]^D[9] ^1^D[3]^D[2]^D[1]; CRC[3], A2=1 = 1^1^D[68]^1^1^1^D[63]^D[62]^1^D[55]^D[53]^D[52]^1^1^1^D[47]^D[44]^1^D[39]^ D[38]^1^1^D[30]^D[29]^1^D[22]^D[20]^1^1^D[15]^D[13]^1^D[7]^D[6]^D[5]; PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 165 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM CRC Write Data Feature CRC[4], A2=0 = 1^1^D[65]^D[64]^1^1^1^D[59]^D[56]^1^D[50]^D[49]^D[48]^1^1^1^D[41]^1^1^D[35 ]^1^1^D[27]^D[26]^D[24]^D[19]^D[17]^1^1^1^D[10]^D[8] ^1^D[3]^D[2]; CRC[4], A2=1 = 1^1^D[69]^D[68]^1^1^1^D[63]^D[60]^1^D[54]^D[53]^D[52]^1^1^1^D[45]^1^1^D[39 ]^1^1^D[31]^D[30]^D[28]^D[23]^D[21]^1^1^1^D[14]^D[12]^1^D[7]^D[6]; CRC[5], A2=0 = 1^D[66]^D[65]^D[64]^1^1^1^D[57]^1^D[51]^D[50]^D[49]^1^1^1^D[42]^D[40]^1^1^ D[32]^1^1^D[27]^D[25]^1^D[18]^D[16]^1^1^D[11]^D[9] ^1^1^D[3]; CRC[5], A2=1 = 1^D[70]^D[69]^D[68]^1^1^1^D[61]^1^D[55]^D[54]^D[53]^1^1^1^D[46]^D[44]^1^1^ D[36]^1^1^D[31]^D[29]^1^D[22]^D[20]^1^1^D[15]^D[13]^1^1^D[7]; CRC[6], A2=0 = D[67]^D[66]^D[65]^D[64]^1^1^D[58]^1^1^D[51]^D[50]^D[48]^1^1^D[43]^D[41]^1^1 ^D[33]^D[32]^1^1^D[26]^1^D[19]^D[17]^D[16]^1^1^D[10]^1^1^1; CRC[6], A2=1 = D[71]^D[70]^D[69]^D[68]^1^1^D[62]^1^1^D[55]^D[54]^D[52]^1^1^D[47]^D[45]^1^1 ^D[37]^D[36]^1^1^D[30]^1^D[23]^D[21]^D[20]^1^1^D[14]^1^1^1; CRC[7], A2=0 = 1^D[67]^D[66]^D[65]^1^1^D[59]^1^1^1^D[51]^D[49]^D[48]^1^1^D[42]^1^1^D[34]^ D[33]^1^1^D[27]^1^1^D[18]^D[17]^1^1^D[11]^1^1^1; CRC[7], A2=1 = 1^D[71]^D[70]^D[69]^1^1^D[63]^1^1^1^D[55]^D[53]^D[52]^1^1^D[46]^1^1^D[38]^ D[37]^1^1^D[31]^1^1^D[22]^D[21]^1^1^D[15]^1^1^1; CRC Error Handling The CRC error mechanism shares the same ALERT_n signal as CA parity for reporting write errors to the DRAM. The controller has two ways to distinguish between CRC errors and CA parity errors: 1) Read DRAM mode/MPR registers, and 2) Measure time ALERT_n is LOW. To speed up recovery for CRC errors, CRC errors are only sent back as a "short" pulse; the maximum pulse width is roughly ten clocks (unlike CA parity where ALERT_n is LOW longer than 45 clocks). The ALERT_n LOW could be longer than the maximum limit at the controller if there are multiple CRC errors as the ALERT_n signals are connected by a daisy chain bus. The latency to ALERT_n signal is defined as tCRC_ALERT in the following figure. The DRAM will set the error status bit located at MR5[3] to a 1 upon detecting a CRC error, which will subsequently set the CRC error status flag in the MPR error log HIGH (MPR Page1, MPR3[7]). The CRC error status bit (and CRC error status flag) remains set at 1 until the DRAM controller clears the CRC error status bit using an MRS command to set MR5[3] to a 0. The DRAM controller, upon seeing an error as a pulse width, will retry the write transactions. The controller should consider the worst-case delay for ALERT_n (during initialization) and backup the transactions accordingly. The DRAM controller may also be made more intelligent and correlate the write CRC error to a specific rank or a transaction. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 166 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM CRC Write Data Feature Figure 100: CRC Error Reporting CK_c CK_t DQIN T0 T1 Dx T2 Dx+1 T3 Dx+2 Dx+3 Dx+4 T4 Dx+5 Dx+6 T5 Dx+7 CRCy T6 Ta0 Ta1 Ta2 Ta3 Tb0 Tb1 1 CRC ALERT_PW (MAX) tCRC_ALERT ALERT_n CRC ALERT_PW (MIN) Transition Data Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. D[71:1] CRC computed by DRAM did not match CRC[7:0] at T5 and started error generating process at T6. 2. CRC ALERT_PW is specified from the point where the DRAM starts to drive the signal LOW to the point where the DRAM driver releases and the controller starts to pull the signal up. 3. Timing diagram applies to x4, x8, and x16 devices. 167 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN CRC Write Data Flow Diagram Figure 101: CA Parity Flow Diagram DRAM write process start MR2 12 enable CRC MR5 3 set CRC error clear to 0 MR5 10 enable/disable DM MR3[10:9] WCL if DM enabled Capture data CRC enabled Persistent mode enabled Yes DRAM CRC same as controller CRC Yes Yes No No Transfer data internally Transfer data internally Transfer Data Internally DRAM CRC same as controller CRC Yes CA error 168 Yes No No MR5[3] = 0 at WRITE ALERT_n LOW 6 to 10 CKs ALERT_n HIGH WRITE burst completed WRITE burst completed No MR5[A3] and PAGE1 MPR3[7] remain set to 1 Yes MR5[3] = 0 at WRITE Set error flag MR5[A3] 1 ALERT_n LOW 6 to 10 CKs Set error status PAGE1 MPR3[7] 1 WRITE burst completed Bad data written MR5 3 reset to 0 if desired ALERT_n HIGH WRITE burst completed No MR5[A3] and PAGE1 MPR3[7] remain set to 1 Yes Set error flag MR5[A3] 1 Set error status PAGE1 MPR3[7] 1 WRITE burst rejected Bad data not written MR5 3 reset to 0 if desired 4Gb: x4, x8, x16 DDR4 SDRAM CRC Write Data Feature Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. WRITE burst completed No 4Gb: x4, x8, x16 DDR4 SDRAM Data Bus Inversion Data Bus Inversion The DATA BUS INVERSION (DBI) function is supported only for x8 and x16 configurations (it is not supported on x4 devices). DBI opportunistically inverts data bits, and in conjunction with the DBI_n I/O, less than half of the DQs will switch LOW for a given DQS strobe edge. The DBI function shares a common pin with the DATA MASK (DM) and TDQS functions. The DBI function applies to either or both READ and WRITE operations: Write DBI cannot be enabled at the same time the DM function is enabled, and DBI is not allowed during MPR READ operation. Valid configurations for TDQS, DM, and DBI functions are shown below. Table 57: DBI vs. DM vs. TDQS Function Matrix Read DBI Write DBI Data Mask (DM) TDQS (x8 only) Enabled (or Disabled) Disabled Disabled Disabled Enabled or Disabled Enabled Disabled Disabled Enabled or Disabled Disabled Enabled Disabled Disabled Disabled Disabled Enabled DBI During a WRITE Operation If DBI_n is sampled LOW on a given byte lane during a WRITE operation, the DRAM inverts write data received on the DQ inputs prior to writing the internal memory array. If DBI_n is sampled HIGH on a given byte lane, the DRAM leaves the data received on the DQ inputs noninverted. The write DQ frame format is shown below for x8 and x16 configurations (the x4 configuration does not support the DBI function). Table 58: DBI Write, DQ Frame Format (x8) Transfer Function 0 1 2 3 4 5 6 7 DQ[7:0] Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 DM_n or DBI_n DM0 or DBI0 DM1 or DBI1 DM2 or DBI2 DM3 or DBI3 DM4 or DBI4 DM5 or DBI5 DM6 or DBI6 DM7 or DBI7 Table 59: DBI Write, DQ Frame Format (x16) Transfer, Lower (L) and Upper(U) Function 0 1 2 3 4 5 6 7 DQ[7:0] LByte 0 LByte 1 LByte 2 LByte 3 LByte 4 LByte 5 LByte 6 LByte 7 LDM_n or LDBI_n LDM0 or LDBI0 LDM1 or LDBI1 LDM2 or LDBI2 LDM3 or LDBI3 LDM4 or LDBI4 LDM5 or LDBI5 LDM6 or LDBI6 LDM7 or LDBI7 DQ[15:8] UByte 0 UByte 1 UByte 2 UByte 3 UByte 4 UByte 5 UByte 6 UByte 7 UDM_n or UDBI_n UDM0 or UDBI0 UDM1 or UDBI1 UDM2 or UDBI2 UDM3 or UDBI3 UDM4 or UDBI4 UDM5 or UDBI5 UDM6 or UDBI6 UDM7 or UDBI7 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 169 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Data Bus Inversion DBI During a READ Operation If the number of 0 data bits within a given byte lane is greater than four during a READ operation, the DRAM inverts read data on its DQ outputs and drives the DBI_n pin LOW; otherwise, the DRAM does not invert the read data and drives the DBI_n pin HIGH. The read DQ frame format is shown below for x8 and x16 configurations (the x4 configuration does not support the DBI function). Table 60: DBI Read, DQ Frame Format (x8) Transfer Byte Function 0 1 2 3 4 5 6 7 DQ[7:0] Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 DBI_n DBI0 DBI1 DBI2 DBI3 DBI4 DBI5 DBI6 DBI7 Table 61: DBI Read, DQ Frame Format (x16) Transfer Byte, Lower (L) and Upper(U) Function 0 1 2 3 4 5 6 7 DQ[7:0] LByte 0 LByte 1 LByte 2 LByte 3 LByte 4 LByte 5 LByte 6 LByte 7 LDBI_n LDBI0 LDBI1 LDBI2 LDBI3 LDBI4 LDBI5 LDBI6 LDBI7 DQ[15:8] UByte 0 UByte 1 UByte 2 UByte 3 UByte 4 UByte 5 UByte 6 UByte 7 UDBI_n UDBI0 UDBI1 UDBI2 UDBI3 UDBI4 UDBI5 UDBI6 UDBI7 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 170 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Data Mask Data Mask The DATA MASK (DM) function, also described as PARTIAL WRITE, is supported only for x8 and x16 configurations (it is not supported on x4 devices). The DM function shares a common pin with the DBI_n and TDQS functions. The DM function applies only to WRITE operations and cannot be enabled at the same time the WRITE DBI function is enabled. The valid configurations for the TDQS, DM, and DBI functions are shown here. Table 62: DM vs. TDQS vs. DBI Function Matrix Data Mask (DM) TDQS (x8 only) Write DBI Read DBI Enabled Disabled Disabled Enabled or Disabled Disabled Enabled Disabled Disabled Disabled Enabled Enabled or Disabled Disabled Disabled Enabled (or Disabled) When enabled, the DM function applies during a WRITE operation. If DM_n is sampled LOW on a given byte lane, the DRAM masks the write data received on the DQ inputs. If DM_n is sampled HIGH on a given byte lane, the DRAM does not mask the data and writes this data into the DRAM core. The DQ frame format for x8 and x16 configurations is shown below. If both CRC write and DM are enabled (via MRS), the CRC will be checked and valid prior to the DRAM writing data into the DRAM core. If a CRC error occurs while the DM feature is enabled, CRC write persistent mode will be enabled and data will not be written into the DRAM core. In the case of CRC write enabled and DM disabled (via MRS), that is, CRC write nonpersistent mode, data is written to the DRAM core even if a CRC error occurs. Table 63: Data Mask, DQ Frame Format (x8) Transfer Function 0 1 2 3 4 5 6 7 DQ[7:0] Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 DM_n or DBI_n DM0 or DBI0 DM1 or DBI1 DM2 or DBI2 DM3 or DBI3 DM4 or DBI4 DM5 or DBI5 DM6 or DBI6 DM7 or DBI7 Table 64: Data Mask, DQ Frame Format (x16) Transfer, Lower (L) and Upper (U) Function 0 1 2 3 4 5 6 7 DQ[7:0] LByte 0 LByte 1 LByte 2 LByte 3 LByte 4 LByte 5 LByte 6 LByte 7 LDM_n or LDBI_n LDM0 or LDBI0 LDM1 or LDBI1 LDM2 or LDBI2 LDM3 or LDBI3 LDM4 or LDBI4 LDM5 or LDBI5 LDM6 or LDBI6 LDM7 or LDBI7 DQ[15:8] UByte 0 UByte 1 UByte 2 UByte 3 UByte 4 UByte 5 UByte 6 UByte 7 UDM_n or UDBI_n UDM0 or UDBI0 UDM1 or UDBI1 UDM2 or UDBI2 UDM3 or UDBI3 UDM4 or UDBI4 UDM5 or UDBI5 UDM6 or UDBI6 UDM7 or UDBI7 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 171 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Programmable Preamble Modes and DQS Postambles Programmable Preamble Modes and DQS Postambles The device supports programmable WRITE and READ preamble modes, either the normal 1tCK preamble mode or special 2tCK preamble mode. The 2 tCK preamble mode places special timing constraints on many operational features as well as being supported for data rates of DDR4-2400 and faster. The WRITE preamble 1 tCK or 2tCK mode can be selected independently from READ preamble 1tCK or 2tCK mode. READ preamble training is also supported; this mode can be used by the DRAM controller to train or "read level" the DQS receivers. There are tCCD restrictions under some circumstances: • When 2tCK READ preamble mode is enabled, a tCCD_S or tCCD_L of 5 clocks is not allowed. • When 2tCK WRITE preamble mode is enabled and write CRC is not enabled, a tCCD_S or tCCD_L of 5 clocks is not allowed. • When 2tCK WRITE preamble mode is enabled and write CRC is enabled, a tCCD_S or tCCD_L of 6 clocks is not allowed. WRITE Preamble Mode MR4[12] = 0 selects 1tCK WRITE preamble mode while MR4[12] = 1 selects 2 tCK WRITE preamble mode. Examples are shown in the figures below. Figure 102: 1tCK vs. 2tCK WRITE Preamble Mode 1tCK Mode WR WL CK_c CK_t Preamble DQS_t, DQS_c DQ D0 D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3 D4 D5 D6 D7 2tCK Mode WR WL CK_c CK_t Preamble DQS_t, DQS_c DQ PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 172 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Programmable Preamble Modes and DQS Postambles CWL has special considerations when in the 2tCK WRITE preamble mode. The CWL value selected in MR2[5:3], as seen in table below, requires at least one additional clock when the primary CWL value and 2tCK WRITE preamble mode are used; no additional clocks are required when the alternate CWL value and 2tCK WRITE preamble mode are used. Table 65: CWL Selection CWL - Primary Choice Speed Bin 1tCK Preamble 2tCK CWL - Alternate Choice Preamble 1tCK Preamble 2tCK Preamble DDR4-1600 9 N/A 11 N/A DDR4-1866 10 N/A 12 N/A DDR4-2133 11 N/A 14 N/A DDR4-2400 12 14 16 16 DDR4-2666 14 16 18 18 DDR4-2933 16 18 20 20 DDR4-3200 16 18 20 20 Note: 1. CWL programmable requirement for MR2[5:3]. When operating in 2tCK WRITE preamble mode, tWTR (command based) and tWR (MR0[11:9]) must be programmed to a value 1 clock greater than the tWTR and tWR setting normally required for the applicable speed bin to be JEDEC compliant; however, Micron's DDR4 DRAMs do not require these additional tWTR and tWR clocks. The CAS_n-to-CAS_n command delay to either a different bank group (tCCD_S) or the same bank group (tCCD_L) have minimum timing requirements that must be satisfied between WRITE commands and are stated in the Timing Parameters by Speed Bin tables. When operating in 2tCK WRITE preamble mode, tCCD_S and tCCD_L must also be an even number of clocks. As an example, if the minimum timing specification requires only 5tCK, the 5tCK has to be rounded up to 6tCK when operating in 2tCK WRITE preamble mode, while 5tCK would be acceptable if operating in 1tCK WRITE preamble mode. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 173 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Programmable Preamble Modes and DQS Postambles Figure 103: 1tCK vs. 2tCK WRITE Preamble Mode, tCCD = 4 1t CK Mode CMD WRITE WRITE CK_c CK_t tCCD =4 WL DQS_t, DQS_c Preamble D0 DQ D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3 D1 D2 D3 D4 D5 D6 D7 D0 D1 2t CK Mode CMD WRITE WRITE CK_c CK_t tCCD DQS_t, DQS_c =4 WL Preamble D0 DQ PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 174 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Programmable Preamble Modes and DQS Postambles Figure 104: 1tCK vs. 2tCK WRITE Preamble Mode, tCCD = 5 1t CK Mode CMD WRITE WRITE CK_c CK_t tCCD =5 WL DQS_t, DQS_c Preamble Preamble D0 DQ D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3 2t CK Mode: t CCD = 5 is not allowed in 2t CK mode. Note: 1. tCCD_S and tCCD_L = 5 tCKs is not allowed when in 2tCK WRITE preamble mode. Figure 105: 1tCK vs. 2 tCK WRITE Preamble Mode, tCCD = 6 1t CK Mode CMD WRITE WRITE CK_c CK_t tCCD =6 WL DQS_t, DQS_c Preamble Preamble D0 DQ D1 D2 D3 D4 D5 D6 D7 D5 D6 D7 D0 D1 D2 D3 D0 D1 D2 D3 2t CK Mode CMD WRITE WRITE CK_c CK_t tCCD DQS_t, DQS_c =6 WL Preamble Preamble D0 DQ PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 175 D1 D2 D3 D4 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Programmable Preamble Modes and DQS Postambles READ Preamble Mode MR4[11] = 0 selects 1tCK READ preamble mode and MR4[12] = 1 selects 2tCK READ preamble mode. Examples are shown in the following figure. Figure 106: 1tCK vs. 2tCK READ Preamble Mode 1tCK Mode RD CL CK_c CK_t Preamble DQS_t, DQS_c DQ D0 D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3 D4 D5 D6 D7 2tCK Mode RD CL CK_c CK_t Preamble DQS_t, DQS_c DQ READ Preamble Training DDR4 supports READ preamble training via MPR reads; that is, READ preamble training is allowed only when the DRAM is in the MPR access mode. The READ preamble training mode can be used by the DRAM controller to train or "read level" its DQS receivers. READ preamble training is entered via an MRS command (MR4[10] = 1 is enabled and MR4[10] = 0 is disabled). After the MRS command is issued to enable READ preamble training, the DRAM DQS signals are driven to a valid level by the time tSDO is satisfied. During this time, the data bus DQ signals are held quiet, that is, driven HIGH. The DQS_t signal remains driven LOW and the DQS_c signal remains driven HIGH until an MPR Page0 READ command is issued (MPR0 through MPR3 determine which pattern is used), and when CAS latency (CL) has expired, the DQS signals will toggle normally depending on the burst length setting. To exit READ preamble training mode, an MRS command must be issued, MR4[10] = 0. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 176 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Programmable Preamble Modes and DQS Postambles Figure 107: READ Preamble Training CMD MRS MPR RD tSDO CL DQS_c DQS_t, DQs (Quiet/Driven HIGH) D0 D1 D2 D3 D4 D5 D6 D7 WRITE Postamble Whether the 1tCK or 2tCK WRITE preamble mode is selected, the WRITE postamble remains the same at ½tCK. Figure 108: WRITE Postamble 1tCK Mode WR WL CK_c CK_t Postamble DQS_t, DQS_c D0 DQ D1 D2 D3 D4 D5 D6 D7 2tCK Mode WR WL CK_c CK_t Postamble DQS_t, DQS_c DQ D0 D1 D2 D3 D4 D5 D6 D7 READ Postamble Whether the 1tCK or 2tCK READ preamble mode is selected, the READ postamble remains the same at ½tCK. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 177 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Programmable Preamble Modes and DQS Postambles Figure 109: READ Postamble 1tCK Mode RD CL CK_c CK_t Postamble DQS_t, DQS_c D0 DQ D1 D2 D3 D4 D5 D6 D7 2tCK Mode RD CL CK_c CK_t Postamble DQS_t, DQS_c DQ PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN D0 178 D1 D2 D3 D4 D5 D6 D7 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Bank Access Operation Bank Access Operation DDR4 supports bank grouping: x4/x8 DRAMs have four bank groups (BG[1:0]), and each bank group is comprised of four subbanks (BA[1:0]); x16 DRAMs have two bank groups (BG[0]), and each bank group is comprised of four subbanks. Bank accesses to different banks' groups require less time delay between accesses than bank accesses to within the same bank's group. Bank accesses to different bank groups require tCCD_S (or short) delay between commands while bank accesses within the same bank group require tCCD_L (or long) delay between commands. Figure 110: Bank Group x4/x8 Block Diagram Bank 3 Bank 2 Bank 1 Bank 0 Memory Array Bank Group 0 CMD/ADDR Bank 3 Bank 2 Bank 1 Bank 0 Memory Array Bank 3 Bank 2 Bank 1 Bank 0 Memory Array Bank Group 1 Bank Group 2 Bank 3 Bank 2 Bank 1 Bank 0 Memory Array Bank Group 3 CMD/ADDR register Sense amplifiers Sense amplifiers Sense amplifiers Sense amplifiers Local I/O gating Local I/O gating Local I/O gating Local I/O gating Global I/O gating Data I/O 1. Bank accesses to different bank groups require tCCD_S. 2. Bank accesses within the same bank group require tCCD_L. Notes: Table 66: DDR4 Bank Group Timing Examples PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Parameter DDR4-1600 DDR4-2133 DDR4-2400 tCCD_S 4nCK 4nCK 4nCK tCCD_L 4nCK or 6.25ns 4nCK or 5.355ns 4nCK or 5ns tRRD_S (½K) 4nCK or 5ns 4nCK or 3.7ns 4nCK or 3.3ns tRRD_L (½K) 4nCK or 6ns 4nCK or 5.3ns 4nCK or 4.9ns tRRD_S (1K) 4nCK or 5ns 4nCK or 3.7ns 4nCK or 3.3ns tRRD_L (1K) 4nCK or 6ns 4nCK or 5.3ns 4nCK or 4.9ns tRRD_S (2K) 4nCK or 6ns 4nCK or 5.3ns 4nCK or 5.3ns tRRD_L (2K) 4nCK or 7.5ns 4nCK or 6.4ns 4nCK or 6.4ns 179 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Bank Access Operation Table 66: DDR4 Bank Group Timing Examples (Continued) Notes: Parameter DDR4-1600 DDR4-2133 DDR4-2400 tWTR_S 2nCK or 2.5ns 2nCK or 2.5ns 2nCK or 2.5ns tWTR_L 4nCK or 7.5ns 4nCK or 7.5ns 4nCK or 7.5ns 1. Refer to Timing Tables for actual specification values, these values are shown for reference only and are not verified for accuracy. 2. Timings with both nCK and ns require both to be satisfied; that is, the larger time of the two cases must be satisfied. Figure 111: READ Burst tCCD_S and tCCD_L Examples CK_c CK_t Command T0 T1 READ DES T2 T3 T4 T5 T6 T7 T8 T9 T10 T11 DES DES READ DES DES DES DES DES READ DES tCCD_L tCCD_S Bank Group (BG) BG a BG b BG b Bank Bank c Bank c Bank c Address Col n Col n Col n Don’t Care Notes: 1. tCCD_S; CAS_n-to-CAS_n delay (short). Applies to consecutive CAS_n to different bank groups (T0 to T4). 2. tCCD_L; CAS_n-to-CAS_n delay (long). Applies to consecutive CAS_n to the same bank group (T4 to T10). Figure 112: Write Burst tCCD_S and tCCD_L Examples CK_c CK_t Command T0 T1 WRITE DES T2 T3 T4 T5 T6 DES DES WRITE DES DES T7 T8 T9 T10 T11 DES DES DES WRITE DES tCCD_L tCCD_S Bank Group (BG) BG a BG b BG b Bank Bank c Bank c Bank c Coln Coln Coln Address Don’t Care Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. tCCD_S; CAS_n-to-CAS_n delay (short). Applies to consecutive CAS_n to different bank groups (T0 to T4). 2. tCCD_L; CAS_n-to-CAS_n delay (long). Applies to consecutive CAS_n to the same bank group (T4 to T10). 180 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Bank Access Operation Figure 113: tRRD Timing CK_c CK_t Command T0 T1 ACT DES T2 T3 T4 T5 T6 DES DES ACT DES DES T8 T9 T10 T11 DES DES DES ACT DES tRRD_L tRRD_S Bank Group (BG) T7 BG a BG b BG b Bank Bank c Bank c Bank d Address Row n Row n Row n Don’t Care 1. tRRD_S; ACTIVATE-to-ACTIVATE command period (short); applies to consecutive ACTIVATE commands to different bank groups (T0 and T4). 2. tRRD_L; ACTIVATE-to-ACTIVATE command period (long); applies to consecutive ACTIVATE commands to the different banks in the same bank group (T4 and T10). Notes: Figure 114: tWTR_S Timing (WRITE-to-READ, Different Bank Group, CRC and DM Disabled) T0 T1 T2 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Tb0 Tb1 WRITE Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid READ Valid CK_c CK_t Command tWTR_S Bank Group Bank Address BGa BGb Bank c Bank c Col n Col n tWPRE tWPST DQS, DQS_c DI n DQ DI n+ 1 DI n+ 2 DI n+ 3 DI n+ 4 DI n+ 5 DI n+ 6 DI n+ 7 RL WL Time Break Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. tWTR_S: delay from start of internal write transaction to internal READ command to a different bank group. 181 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Bank Access Operation Figure 115: tWTR_L Timing (WRITE-to-READ, Same Bank Group, CRC and DM Disabled) T0 T1 T2 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Tb0 Tb1 WRITE Valid Valid Valid Valid Valid Valid Valid Valid Valid Valid READ Valid CK_c CK_t Command tWTR_L Bank Group Bank Address BGa BGa Bank c Bank c Col n Col n tWPRE tWPST DQS, DQS_c DI n DQ DI n+ 1 DI n+ 2 DI n+ 3 DI n+ 4 DI n+ 5 DI n+ 6 DI n+ 7 RL WL Time Break Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. tWTR_L: delay from start of internal write transaction to internal READ command to the same bank group. 182 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation READ Operation Read Timing Definitions The read timings shown below are applicable in normal operation mode, that is, when the DLL is enabled and locked. Note: tDQSQ = both rising/falling edges of DQS; no tAC defined. Rising data strobe edge parameters: • tDQSCK (MIN)/(MAX) describes the allowed range for a rising data strobe edge relative to CK. • tDQSCK is the actual position of a rising strobe edge relative to CK. • tQSH describes the DQS differential output HIGH time. • tDQSQ describes the latest valid transition of the associated DQ pins. • tQH describes the earliest invalid transition of the associated DQ pins. Falling data strobe edge parameters: • tQSL describes the DQS differential output LOW time. • tDQSQ describes the latest valid transition of the associated DQ pins. • tQH describes the earliest invalid transition of the associated DQ pins. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 183 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 116: Read Timing Definition CK_c CK_t tDQSCK tDQSCK tDQSCK (MIN) tDQSCK (MAX) tDQSCK (MIN) tDQSCK (MAX) MAX center tDQSCK MIN tDQSCKi tDQSCKi Rising strobe region window Rising strobe region window tDQSCKi tDQSCKi Rising strobe region window Rising strobe region window tDQSCKi tDQSCKi Rising strobe region window Rising strobe region window tDQSCK tDQSCK tQSH/DQS_c tQSH/DQS_t DQS_c DQS_t tQH tQH tDQSQ tDQSQ Associated DQ Pins Read Timing – Clock-to-Data Strobe Relationship The clock-to-data strobe relationship shown below is applicable in normal operation mode, that is, when the DLL is enabled and locked. Rising data strobe edge parameters: • tDQSCK (MIN)/(MAX) describes the allowed range for a rising data strobe edge relative to CK. • tDQSCK is the actual position of a rising strobe edge relative to CK. • tQSH describes the data strobe high pulse width. • tHZ(DQS) DQS strobe going to high, nondrive level (shown in the postamble section of the figure below). Falling data strobe edge parameters: • tQSL describes the data strobe low pulse width. • tLZ(DQS) DQS strobe going to low, initial drive level (shown in the preamble section of the figure below). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 184 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 117: Clock-to-Data Strobe Relationship RL measured to this point CK_t CK_c tDQSCK (MIN) tDQSCK (MIN) tDQSCK (MIN) tDQSCK (MIN) tHZ(DQS) MIN tLZ(DQS) MIN DQS_t, DQS_c Early Strobe tQSH tQSL tQSH tQSL tQSH tQSL Bit 0 Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 tRPRE Bit 7 tRPST tDQSCK (MAX) tDQSCK (MAX) tDQSCK (MAX) tDQSCK (MAX) tLZ(DQS) MAX DQS_t, DQS_c Late Strobe Bit 0 tRPRE Notes: tQSH Bit 1 tQSL Bit 2 Bit 3 tQSH Bit 4 Bit 5 Bit 6 tHZ(DQS) MAX tRPST Bit 7 tQSL 1. Within a burst, the rising strobe edge will vary within tDQSCKj while at the same voltage and temperature. However, when the device, voltage, and temperature variations are incorporated, the rising strobe edge variance window can shift between tDQSCK (MIN) and tDQSCK (MAX). 2. 3. 4. 5. 6. 7. 8. A timing of this window's right edge (latest) from rising CK_t, CK_c is limited by a device's actual tDQSCK (MAX). A timing of this window's left inside edge (earliest) from rising CK_t, CK_c is limited by tDQSCK (MIN). Notwithstanding Note 1, a rising strobe edge with tDQSCK (MAX) at T(n) can not be immediately followed by a rising strobe edge with tDQSCK (MIN) at T(n + 1) because other timing relationships (tQSH, tQSL) exist: if tDQSCK(n + 1) < 0: tDQSCK(n) < 1.0 tCK - (tQSH (MIN) + tQSL (MIN)) - | tDQSCK(n + 1) |. The DQS_t, DQS_c differential output HIGH time is defined by tQSH, and the DQS_t, DQS_c differential output LOW time is defined by tQSL. tLZ(DQS) MIN and tHZ(DQS) MIN are not tied to tDQSCK (MIN) (early strobe case), and tLZ(DQS) MAX and tHZ(DQS) MAX are not tied to tDQSCK (MAX) (late strobe case). The minimum pulse width of READ preamble is defined by tRPRE (MIN). The maximum READ postamble is bound by tDQSCK (MIN) plus tQSH (MIN) on the left side and tHZDSQ (MAX) on the right side. The minimum pulse width of READ postamble is defined by tRPST (MIN). The maximum READ preamble is bound by tLZDQS (MIN) on the left side and tDQSCK (MAX) on the right side. Read Timing – Data Strobe-to-Data Relationship The data strobe-to-data relationship is shown below and is applied when the DLL is enabled and locked. Note: tDQSQ: both rising/falling edges of DQS; no tAC defined. Rising data strobe edge parameters: • tDQSQ describes the latest valid transition of the associated DQ pins. • tQH describes the earliest invalid transition of the associated DQ pins. Falling data strobe edge parameters: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 185 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation • tDQSQ describes the latest valid transition of the associated DQ pins. • tQH describes the earliest invalid transition of the associated DQ pins. Data valid window parameters: • tDVWd is the Data Valid Window per device per UI and is derived from [ tQH - tDQSQ] of each UI on a given DRAM • tDVWp is the Data Valid Window per pin per UI and is derived [ tQH - tDQSQ] of each UI on a pin of a given DRAM Figure 118: Data Strobe-to-Data Relationship T0 T1 T2 T9 T10 T11 T12 T13 T14 T15 T16 Command3 READ DES DES DES DES DES DES DES DES DES DES Address4 Bank, Col n CK_c CK_t RL = AL + CL tDQSQ tRPRE tDQSQ (MAX) (MAX) tRPST (1nCK) DQS_t, DQS_c tQH DQ2 (Last data ) tQH DOUT n DOUT n+1 DOUT n+2 DOUT n+3 DOUT n+4 DOUT n+5 DOUT n+6 DOUT n+7 tDVWp DQ2 (First data no longer) DOUT n+1 DOUT n DOUT n+2 DOUT n+3 DOUT n+4 DOUT n+5 DOUT n+6 DOUT n+7 tDVWp DOUT n All DQ collectively DOUT n+1 DOUT n+2 DOUT n+3 DOUT n+4 DOUT n+5 tDVWd Notes: DOUT n+6 DOUT n+7 tDVWd Don’t Care 1. BL = 8, RL = 11 (AL = 0, CL = 1) , Premable = 1tCK. 2. DOUTn = data-out from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[A1:0 = 00] or MR0[A1:0 = 01] and A12 = 1 during READ commands at T0. 5. Output timings are referenced to VDDQ, and DLL on for locking. 6. tDQSQ defines the skew between DQS to data and does not define DQS to clock. 7. Early data transitions may not always happen at the same DQ. Data transitions of a DQ can vary (either early or late) within a burst. tLZ(DQS), tLZ(DQ), tHZ(DQS), and tHZ(DQ) Calculations tHZ and tLZ transitions occur in the same time window as valid data transitions. These parameters are referenced to a specific voltage level that specifies when the device output is no longer driving tHZ(DQS) and tHZ(DQ), or begins driving tLZ(DQS) and tLZ(DQ). The figure below shows a method to calculate the point when the device is no longer driving tHZ(DQS) and tHZ(DQ), or begins driving tLZ(DQS) and tLZ(DQ), by measuring the signal at two different voltages. The actual voltage measurement points are not critical as long as the calculation is consistent. tLZ(DQS), tLZ(DQ), tHZ(DQS), and tHZ(DQ) are defined as singled-ended parameters. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 186 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 119: tLZ and tHZ Method for Calculating Transitions and Endpoints tLZ(DQ): CK_t, CK_c rising crossing at RL tHZ(DQ) tHZ(DQ) with BL8: CK_t, CK_c rising crossing at RL + 4CK with BC4: CK_t, CK_c rising crossing at RL + 2CK CK_t CK_c Begin point: Extrapolated point at VDDQ DQ tLZ tHZ VDDQ VDDQ VSW2 DQ VSW2 0.7 × VDDQ 0.7 × VDDQ VSW1 VSW1 0.4 × VDDQ 0.4 × VDDQ Begin point: Extrapolated point (low level) Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Vsw1 = (0.70 - 0.04) × VDDQ for both tLZ and tHZ. 2. Vsw2 = (0.70 + 0.04) × VDDQ for both tLZ and tHZ. 3. Extrapolated point (low level) = VDDQ/(50 + 34) × 34 = 0.4 × VDDQ Driver impedance = RZQ/7 = 34Ω VTT test load = 50Ω to VDDQ. 187 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation tRPRE Calculation Figure 120: tRPRE Method for Calculating Transitions and Endpoints CK_t VREFCA CK_c Single-ended signal provided as background information VDDQ DQS_t 0.7 × VDDQ 0.4 × VDDQ DQS_c VDDQ 0.7 × VDDQ 0.4 × VDDQ DQS_t DQS_t DQS_c VDDQ 0.7 × VDDQ DQS_c 0.4 × VDDQ Resulting differential signal relevant for tRPRE specification 0.6 × VDDQ VSW2 0.3 × VDDQ VSW1 DQS_t, DQS_c 0V tRPRE Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN begins (t1) tRPRE ends (t2) 1. Vsw1 = (0.3 - 0.04) × VDDQ. 2. Vsw2 = (0.30 + 0.04) × VDDQ. 3. DQS_t and DQS_c low level = VDDQ/(50 + 34) × 34 = 0.4 × VDDQ Driver impedance = RZQ/7 = 34Ω VTT test load = 50Ω to VDDQ. 188 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation tRPST Calculation Figure 121: tRPST Method for Calculating Transitions and Endpoints CK_t VREFCA CK_c Single-ended signal provided as background information VDDQ 0.7 × VDDQ 0.4 × VDDQ DQS_t VDDQ DQS_c 0.7 × VDDQ 0.4 × VDDQ VDDQ DQS_c 0.7 × VDDQ DQS_t Resulting differential signal relevant for tRPST specification tRPST begins (t1) 0V VSW2 –0.3 × VDDQ VSW1 –0.6 × VDDQ DQS_t, DQS_c tRPST Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN ends (t2) 1. Vsw1 = (–0.3 - 0.04) × VDDQ. 2. Vsw2 = (–0.30 + 0.04) × VDDQ. 3. DQS_t and DQS_c low level = VDDQ/(50 + 34) × 34 = 0.4 × VDDQ Driver impedance = RZQ/7 = 34Ω VTT test load = 50Ω to VDDQ. 189 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation READ Burst Operation DDR4 READ commands support bursts of BL8 (fixed), BC4 (fixed), and BL8/BC4 onthe-fly (OTF); OTF uses address A12 to control OTF when OTF is enabled: • A12 = 0, BC4 (BC4 = burst chop) • A12 = 1, BL8 READ commands can issue precharge automatically with a READ with auto precharge command (RDA), and is enabled by A10 HIGH: • READ command with A10 = 0 (RD) performs standard read, bank remains active after READ burst. • READ command with A10 = 1 (RDA) performs read with auto precharge, bank goes in to precharge after READ burst. Figure 122: READ Burst Operation, RL = 11 (AL = 0, CL = 11, BL8) T0 T1 T2 Ta0 Ta1 Ta2 Ta3 Ta4 Ta5 Ta6 Ta7 Ta8 Ta9 READ DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command Bank Group Address BGa Address Bank col n tRPRE tRPST DQS_t DQS_c DO n DQ DO n+ 1 DO n+ 2 DO n+ 3 DO n+ 4 DO n+ 5 DO n+ 6 DO n+ 7 CL = 11 RL = AL + CL Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL8, RL = 0, AL = 0, CL = 11, Preamble = 1tCK. 2. DO n = data-out from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ command at T0. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. 190 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 123: READ Burst Operation, RL = 21 (AL = 10, CL = 11, BL8) T0 T1 Ta0 Ta1 Ta2 Ta3 Tb0 Tb1 Tb2 Tb3 Tb4 Tb5 Tb6 READ DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command Bank Group Address BGa Address Bank col n tRPRE tRPST DQS_t DQS_c DO n DQ AL = 10 DO n+ 1 DO n+ 2 DO n+ 3 DO n+ 4 DO n+ 5 DO n+ 6 DO n+ 7 CL = 11 RL = AL + CL Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL8, RL = 21, AL = (CL - 1), CL = 11, Preamble = 1tCK. 2. DO n = data-out from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ command at T0. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. 191 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation READ Operation Followed by Another READ Operation Figure 124: Consecutive READ (BL8) with 1tCK Preamble in Different Bank Group T0 T1 READ DES T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES T2 CK_c CK_t Command DES tCCD_S =4 Bank Group Address BGa BGb Address Bank Col n Bank Col b tRPRE tRPST DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DO b DO b+1 DO b+2 DO b+3 DO b+4 DO b+5 DO b+6 DO b+7 RL = 11 Time Break Transitioning Data Don’t Care 1. BL8, AL = 0, CL = 11, Preamble = 1tCK. 2. DO n (or b) = data-out from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and T4. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. Notes: Figure 125: Consecutive READ (BL8) with 2tCK Preamble in Different Bank Group T0 T1 READ DES T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES T2 CK_c CK_t Command DES tCCD_S =4 Bank Group Address BGa BGb Address Bank Col n Bank Col b tRPRE tRPST DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DO b DO b+1 DO b+2 DO b+3 DO b+4 DO b+5 DO b+6 DO b+7 RL = 11 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL8, AL = 0, CL = 11, Preamble = 2tCK. 2. DO n (or b) = data-out from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and T4. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. 192 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 126: Nonconsecutive READ (BL8) with 1tCK Preamble in Same or Different Bank Group T0 T1 READ DES T2 T3 T4 DES DES T5 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 READ DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command DES tCCD_S/L =5 Bank Group Address BGa BGb Address Bank Col n Bank Col b tRPRE tRPST DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DO b DO b+1 DO b+2 DO b+3 DO b+4 DO b+5 DO b+6 DO b+7 RL = 11 Time Break Don’t Care Transitioning Data 1. BL8, AL = 0, CL = 11, Preamble = 1tCK, tCCD_S/L = 5. 2. DO n (or b) = data-out from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and T5. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. Notes: Figure 127: Nonconsecutive READ (BL8) with 2tCK Preamble in Same or Different Bank Group T0 T1 READ DES T5 T6 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES T2 CK_c CK_t Command DES tCCD_S/L =6 Bank Group Address BGa BGa or BGb Address Bank Col n Bank Col b tRPRE tRPRE tRPST DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DO b DO b+1 DO b+2 DO b+3 DO b+4 DO b+5 DO b+6 DO b+7 RL = 11 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL8, AL = 0, CL = 11, Preamble = 2tCK, tCCD_S/L = 6. 2. DO n (or b) = data-out from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[A1:0 = 00] or MR0[A1:0 = 01] and A12 = 1 during READ commands at T0 and T6. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. 6. 6 tCCD_S/L = 5 isn’t allowed in 2tCK preamble mode. 193 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 128: READ (BC4) to READ (BC4) with 1tCK Preamble in Different Bank Group T0 T1 READ DES T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES T2 CK_c CK_t Command DES tCCD_S =4 Bank Group Address BGa BGb Address Bank Col n Bank Col b tRPRE tRPST tRPRE tRPST DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO b DO b+1 DO b+2 DO b+3 RL = 11 Time Break Transitioning Data Don’t Care 1. BL8, AL = 0, CL = 11, Preamble = 1tCK. 2. DO n (or b) = data-out from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by either MR0[1:0] = 10 or MR0[1:0] = 01 and A12 = 0 during READ commands at T0 and T4. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. Notes: Figure 129: READ (BC4) to READ (BC4) with 2tCK Preamble in Different Bank Group T0 T1 READ DES T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command DES tCCD_S =4 Bank Group Address BGa BGb Address Bank Col n Bank Col b tRPRE tRPRE tRPST DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO b DO b+1 DO b+2 DO b+3 RL = 11 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL8, AL = 0, CL = 11, Preamble = 2tCK. 2. DO n (or b) = data-out from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by either MR0[1:0] = 10 or MR0[1:0] = 01 and A12 = 0 during READ commands at T0 and T4. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. 194 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 130: READ (BL8) to READ (BC4) OTF with 1tCK Preamble in Different Bank Group T0 T1 READ DES T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES T2 CK_c CK_t Command DES tCCD_S =4 Bank Group Address BGa BGb Address Bank Col n Bank Col b t RPRE tRPST DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DO b DO b+1 DO b+2 DO b+3 RL = 11 Time Break Notes: Transitioning Data Don’t Care 1. BL = 8, AL =0, CL = 11, Preamble = 1tCK. 2. DO n (or b) = data-out from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T0. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during READ commands at T4. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. Figure 131: READ (BL8) to READ (BC4) OTF with 2tCK Preamble in Different Bank Group T0 T1 READ DES T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command DES tCCD_S =4 Bank Group Address BGa BGb Address Bank Col n Bank Col b tRPRE tRPST DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DO b DO b+1 DO b+2 DO b+3 RL = 11 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL = 8, AL =0, CL = 11, Preamble = 2tCK. 2. DO n (or b) = data-out from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T0. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during READ commands at T4. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. 195 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 132: READ (BC4) to READ (BL8) OTF with 1tCK Preamble in Different Bank Group T0 T1 READ DES T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command DES tCCD_S Bank Group Address Address =4 BGa BGb Bank Col n Bank Col b tRPST tRPRE tRPST tRPRE DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO b DO b+1 DO b+2 DO b+3 DO b+4 DO b+5 DO b+6 DO b+7 RL = 11 Time Break Notes: Transitioning Data Don’t Care 1. BL = 8, AL =0, CL = 11, Preamble = 1tCK. 2. DO n (or b) = data-out from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during READ commands at T0. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T4. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. Figure 133: READ (BC4) to READ (BL8) OTF with 2tCK Preamble in Different Bank Group T0 T1 READ DES T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command tCCD_S Bank Group Address Address =4 BGa BGb Bank Col n Bank Col b tRPST tRPRE DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO b DO b+1 DO b+2 DO b+3 DO b+4 DO b+5 DO b+6 DO b+7 RL = 11 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL = 8, AL = 0, CL = 11, Preamble = 2tCK. 2. DO n (or b) = data-out from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during READ commands at T0. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T4. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. 196 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation READ Operation Followed by WRITE Operation Figure 134: READ (BL8) to WRITE (BL8) with 1tCK Preamble in Same or Different Bank Group T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES T22 CK_c CK_t Command READ DES tWR READ to WRITE command delay = RL +BL/2 - WL + 2 tCK Bank Group Address Address tWTR 4 Clocks BGa BGa or BGb Bank Col n Bank Col b tRPRE tWPST tWPRE tRPST DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 WL = 9 Time Break Notes: Transitioning Data Don’t Care 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK. 2. DO n = data-out from column n; DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and WRITE commands at T8. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. Figure 135: READ (BL8) to WRITE (BL8) with 2tCK Preamble in Same or Different Bank Group T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22 DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command READ READ to WRITE command delay = RL +BL/2 - WL + 3 tCK Bank Group Address Address 4 Clocks BGa BGa or BGb Bank Col n Bank Col b t t RPRE RPST t t WPRE t WR t WTR WPST DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 WL = 10 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 2tCK, WL = 10 (CWL = 9+1 [see Note 5], AL = 0), WRITE preamble = 2tCK. 2. DO n = data-out from column n; DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 197 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and WRITE commands at T8. 5. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock greater than the lowest CWL setting. 6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. Figure 136: READ (BC4) OTF to WRITE (BC4) OTF with 1tCK Preamble in Same or Different Bank Group T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command tWR READ to WRITE command delay = RL +BL/2 - WL + 2 tCK Bank Group Address Address tWTR 4 Clocks BGa BGa or BGb Bank Col n Bank Col b tRPRE tRPST tWPST tWPRE DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DI b DI b+1 DI b+2 DI b+3 WL = 9 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BC = 4, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK. 2. DO n = data-out from column n; DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 (OTF) setting activated by MR0[1:0] = 01 and A12 = 0 during READ commands at T0 and WRITE commands at T6. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. 198 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 137: READ (BC4) OTF to WRITE (BC4) OTF with 2tCK Preamble in Same or Different Bank Group T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command READ tWR READ to WRITE command delay = RL +BL/2 - WL + 3 tCK Bank Group Address Address tWTR 4 Clocks BGa BGa or BGb Bank Col n Bank Col b tRPRE tWPST tWPRE tRPST DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DI b DI b+1 DI b+2 DI b+3 WL = 10 Time Break Notes: Transitioning Data Don’t Care 1. BC = 4, RL = 11 (CL = 11, AL = 0), READ preamble = 2tCK, WL = 10 (CWL = 9 + 1 [see Note 5], AL = 0), WRITE preamble = 2tCK. 2. DO n = data-out from column n; DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 (OTF) setting activated by MR0[1:0] = 01 and A12 = 0 during READ commands at T0 and WRITE commands at T6. 5. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock greater than the lowest CWL setting. 6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. Figure 138: READ (BC4) Fixed to WRITE (BC4) Fixed with 1tCK Preamble in Same or Different Bank Group T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES T19 T20 DES DES CK_c CK_t Command READ tWR READ to WRITE command delay = RL +BL/2 - WL + 2 tCK Bank Group Address Address tWTR 2 Clocks BGa BGa or BGb Bank Col n Bank Col b tRPRE tRPST tWPST tWPRE DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DI b DI b+1 DI b+2 DI b+3 WL = 9 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BC = 4, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK. 2. DO n = data-out from column n; DI b = data-in from column b. 199 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 (fixed) setting activated by MR0[1:0] = 01. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. Figure 139: READ (BC4) Fixed to WRITE (BC4) Fixed with 2tCK Preamble in Same or Different Bank Group T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command READ tWR READ to WRITE command delay = RL +BL/2 - WL + 3 tCK Bank Group Address Address tWTR 2 Clocks BGa BGa or BGb Bank Col n Bank Col b tRPRE tRPST tWPST tWPRE DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DI b DI b+1 DI b+2 DI b+3 WL = 10 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BC = 4, RL = 11 (CL = 11, AL = 0), READ preamble = 2tCK, WL = 9 (CWL = 9 + 1 [see Note 5], AL = 0), WRITE preamble = 2tCK. 2. DO n = data-out from column n; DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 (fixed) setting activated by MR0[1:0] = 10. 5. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock greater than the lowest CWL setting. 6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. 200 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 140: READ (BC4) to WRITE (BL8) OTF with 1tCK Preamble in Same or Different Bank Group T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES T20 CK_c CK_t Command READ DES tWR READ to WRITE command delay = RL +BL/2 - WL + 2 tCK Bank Group Address Address tWTR 4 Clocks BGa BGa or BGb Bank Col n Bank Col b tRPST tRPRE tWPST tWPRE DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DI b DI b+1 DI b+2 DI b+3 DI n+4 DI n+5 DI n+6 DI n+7 WL = 9 Time Break Notes: Transitioning Data Don’t Care 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK. 2. DO n = data-out from column n; DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T0. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T6. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. Figure 141: READ (BC4) to WRITE (BL8) OTF with 2tCK Preamble in Same or Different Bank Group T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command READ tWR READ to WRITE command delay = RL +BL/2 - WL + 3 tCK Bank Group Address Address tWTR 4 Clocks BGa BGa or BGb Bank Col n Bank Col b tRPST tRPRE tWPST tWPRE DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DI b DI b+1 DI b+2 DI b+3 DI n+4 DI n+5 DI n+6 DI n+7 WL = 10 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 2tCK, WL = 10 (CWL = 9 + 1 [see Note 5], AL = 0), WRITE preamble = 2tCK. 2. DO n = data-out from column n; DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T0. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T6. 201 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. Figure 142: READ (BL8) to WRITE (BC4) OTF with 1tCK Preamble in Same or Different Bank Group T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES T22 CK_c CK_t Command READ DES tWR READ to WRITE command delay = RL +BL/2 - WL + 2 tCK Bank Group Address Address tWTR 4 Clocks BGa BGa or BGb Bank Col n Bank Col b tRPRE tWPST tWPRE tRPST DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DI b DI b+1 DI b+2 DI b+3 WL = 9 Time Break Notes: Transitioning Data Don’t Care 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK. 2. DO n = data-out from column n; DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T0. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T8. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. Figure 143: READ (BL8) to WRITE (BC4) OTF with 2tCK Preamble in Same or Different Bank Group T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22 DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command READ tWR READ to WRITE command delay = RL +BL/2 - WL + 3 tCK Bank Group Address Address 4 Clocks BGa BGa or BGb Bank Col n Bank Col b tRPRE tRPST tWTR tWPST tWPRE DQS_t, DQS_c RL = 11 DO n DQ DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DI b DI b+1 DI b+2 DI b+3 WL = 10 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 2tCK, WL = 10 (CWL = 9 + 1 [see Note 5], AL = 0), WRITE preamble = 2tCK. 2. DO n = data-out from column n; DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 202 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation 4. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during READ commands at T0. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T8. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. READ Operation Followed by PRECHARGE Operation The minimum external READ command to PRECHARGE command spacing to the same bank is equal to AL + tRTP with tRTP being the internal READ command to PRECHARGE command delay. Note that the minimum ACT to PRE timing, tRAS, must be satisfied as well. The minimum value for the internal READ command to PRECHARGE command delay is given by tRTP (MIN) = MAX (4 × nCK, 7.5ns). A new bank ACTIVATE command may be issued to the same bank if the following two conditions are satisfied simultaneously: • The minimum RAS precharge time (tRP [MIN]) has been satisfied from the clock at which the precharge begins. • The minimum RAS cycle time (tRC [MIN]) from the previous bank activation has been satisfied. Figure 144: READ to PRECHARGE with 1tCK Preamble T0 T1 T2 T3 T6 T7 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES READ DES DES DES PRE DES DES DES DES DES DES DES DES ACT DES DES DES CK_c CK_t Command Bank Group Address Address BGa or BGb BGa Bank a Col n BGa Bank a (or all) tRTP Bank a Row b tRP RL = AL + CL BC4 Opertaion DQS_t, DQS_c DQ DO n DO n+1 DO n+2 DO n+3 DO n DO n+1 DO n+2 DO n+3 BL8 Opertaion DQS_t, DQS_c DQ DO n+4 DO n+5 DO n+6 DO n+7 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. RL = 11 (CL = 11, AL = 0 ), Preamble = 1tCK, tRTP = 6, tRP = 11. 2. DO n = data-out from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. The example assumes that tRAS (MIN) is satisfied at the PRECHARGE command time (T7) and that tRC (MIN) is satisfied at the next ACTIVATE command time (T18). 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. 203 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 145: READ to PRECHARGE with 2tCK Preamble T0 T1 T2 T3 T6 T7 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES READ DES DES DES PRE DES DES DES DES DES DES DES DES ACT DES DES DES CK_c CK_t Command Bank Group Address BGa or BGb BGa Bank a Col n Address BGa Bank a (or all) Bank a Row b tRTP tRP RL = AL + CL BC4 Opertaion DQS_t, DQS_c DQ DO n DO n+1 DO n+2 DO n+3 DO n DO n+1 DO n+2 DO n+3 BL8 Opertaion DQS_t, DQS_c DQ DO n+4 DO n+5 DO n+6 DO n+7 Time Break Notes: Transitioning Data Don’t Care 1. RL = 11 (CL = 11, AL = 0 ), Preamble = 2tCK, tRTP = 6, tRP = 11. 2. DO n = data-out from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. The example assumes that tRAS (MIN) is satisfied at the PRECHARGE command time (T7) and that tRC (MIN) is satisfied at the next ACTIVATE command time (T18). 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. Figure 146: READ to PRECHARGE with Additive Latency and 1tCK Preamble T0 T1 T2 T3 T10 T11 T12 T13 T16 T19 T20 T21 T22 T23 T24 T25 T26 T27 DES READ DES DES DES DES DES DES PRE DES DES DES DES DES DES DES DES ACT CK_c CK_t Command Bank Group Address Address BGa or BGb BGa Bank a Col n BGa Bank a (or all) AL = CL - 2 = 9 Bank a Row b tRTP tRP CL = 11 BC4 Opertaion DQS_t, DQS_c DQ DO n DO n+1 DO n+2 DO n+3 DO n DO n+1 DO n+2 DO n+3 BL8 Opertaion DQS_t, DQS_c DQ DO n+4 DO n+5 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN DO n+6 DO n+7 Transitioning Data Don’t Care 1. RL =20 (CL = 11, AL = CL - 2), Preamble = 1tCK, tRTP = 6, tRP = 11. 2. DO n = data-out from column n. 204 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. The example assumes that tRAS (MIN) is satisfied at the PRECHARGE command time (T16) and that tRC (MIN) is satisfied at the next ACTIVATE command time (T27). 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. Figure 147: READ with Auto Precharge and 1tCK Preamble T0 T1 T2 T3 T6 T7 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES RDA DES DES DES PRE DES DES DES DES DES DES DES DES ACT DES DES DES CK_c CK_t Command Bank Group Address Address BGa or BGb BGa Bank a Col n BGa Bank a Col n tRTP Bank a Row b tRP RL = AL + CL BC4 Opertaion DQS_t, DQS_c DQ DO n DO n+1 DO n+2 DO n+3 DO n DO n+1 DO n+2 DO n+3 BL8 Opertaion DQS_t, DQS_c DQ DO n+4 DO n+5 DO n+6 DO n+7 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. RL = 11 (CL = 11, AL = 0 ), Preamble = 1tCK, tRTP = 6, tRP = 11. 2. DO n = data-out from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. tRTP = 6 setting activated by MR0[A11:9 = 001]. 5. The example assumes that tRC (MIN) is satisfied at the next ACTIVATE command time (T18). 6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. 205 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 148: READ with Auto Precharge, Additive Latency, and 1tCK Preamble T0 T1 T2 T3 T10 T11 T12 T13 T16 T19 T20 T21 T22 T23 T24 T25 T26 T27 DES RDA DES DES DES DES DES DES DES DES DES DES DES DES DES DES DES ACT CK_c CK_t Command Bank Group Address BGa BGa Bank a Col n Address Bank a Row b tRTP AL = CL - 2 = 9 tRP CL = 11 BC4 Opertaion DQS_t, DQS_c DQ DO n DO n+1 DO n+2 DO n+3 DO n DO n+1 DO n+2 DO n+3 BL8 Opertaion DQS_t, DQS_c DQ DO n+4 DO n+5 DO n+6 Time Break Notes: DO n+7 Transitioning Data Don’t Care 1. RL = 20 (CL = 11, AL = CL - 2), Preamble = 1tCK, tRTP = 6, tRP = 11. 2. DO n = data-out from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. tRTP = 6 setting activated by MR0[11:9] = 001. 5. The example assumes that tRC (MIN) is satisfied at the next ACTIVATE command time (T27). 6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. READ Operation with Read Data Bus Inversion (DBI) Figure 149: Consecutive READ (BL8) with 1tCK Preamble and DBI in Different Bank Group T0 T1 READ DES T2 T3 T4 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command DES tCCD_S =4 Bank Group Address BGa BGb Address Bank Col n Bank Col b tRPRE tRPST DQS_t, DQS_c RL = 11 + 2 (Read DBI adder) DQ DO n DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DO b DO b+1 DO b+2 DO DO DO b + 3 b +4 _ b + 5 DO b+6 DO b+7 DBI n DBI n+1 DBI n+2 DBI n+3 DBI n+4 DBI n+5 DBI n+6 DBI n+7 DBI b DBI b+1 DBI b+2 DBI b+3 DBI b+6 DBI b+7 RL = 11 + 2 (Read DBI adder) DBI_n Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN DBI DBI b+4 b+5 Transitioning Data Don’t Care 1. BL = 8, AL = 0, CL = 11, Preamble = 1tCK, RL = 11 + 2 (Read DBI adder). 206 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation 2. DO n (or b) = data-out from column n (or b); DBI n (or b) = data bus inversion from column n (or b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and T4. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Enable. READ Operation with Command/Address Parity (CA Parity) Figure 150: Consecutive READ (BL8) with 1tCK Preamble and CA Parity in Different Bank Group T0 T1 READ DES T3 T4 T7 T8 T13 T14 T15 T16 T17 T18 T19 T20 T21 T20 T21 DES READ DES DES DES DES DES DES DES DES DES DES DES DES DES T2 CK_c CK_t Command DES tCCD_S Bank Group Address Address Parity =4 BGa BGb Bank Col n Bank Col b tRPRE tRPST DQS_t, DQS_c RL = 15 DO n DQ DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DO b DO b+1 DO b+2 DO DO DO b + 3 b +4 _ b + 5 DO b+6 DO b+7 RL = 15 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL = 8, AL = 0, CL = 11, PL = 4, (RL = CL + AL + PL = 15), Preamble = 1tCK. 2. DO n (or b) = data-out from column n (or b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[A1:A0 = 00] or MR0[A1:A0 = 01] and A12 = 1 during READ commands at T0 and T4. 5. CA parity = Enable, CS to CA latency = Disable, Read DBI = Disable. 207 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 151: READ (BL8) to WRITE (BL8) with 1tCK Preamble and CA Parity in Same or Different Bank Group T0 T1 T7 T8 T9 T14 T15 T16 T17 T18 T19 T20 T21 T22 T23 T24 T25 DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES T26 CK_c CK_t Command READ DES tWR READ to WRITE command delay = RL +BL/2 - WL + 2 tCK Bank Group Address Address Parity 4 Clocks BGa BGa or BGb Bank Col n Bank Col b tRPRE tRPST tWTR tWPST tWPRE DQS_t, DQS_c RL = 15 DO n DQ DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 WL = 13 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL = 8, AL = 0, CL = 11, PL = 4, (RL = CL + AL + PL = 15), READ preamble = 1tCK, CWL = 9, AL = 0, PL = 4, (WL = CL + AL + PL = 13), WRITE preamble = 1tCK. 2. DO n = data-out from column n, DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and WRITE command at T8. 5. CA parity = Enable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. 208 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation READ Followed by WRITE with CRC Enabled Figure 152: READ (BL8) to WRITE (BL8 or BC4: OTF) with 1tCK Preamble and Write CRC in Same or Different Bank Group T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 READ DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES T22 CK_c CK_t Command DES tWR READ to WRITE command delay = RL +BL/2 - WL + 2 tCK Bank Group Address Address 4 Clocks BGa BGa or BGb Bank Col n Bank Col b tRPRE tRPST tWTR tWPST tWPRE DQS_t, DQS_c RL = 11 DO n DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 CRC DO n DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 CRC DQ x4, READ: BL = 8, WRITE: BC = 4 (OTF) DO n DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DI b DI b+1 DI b+2 DI b+3 CRC DQ x8/X16, READ: BL = 8, WRITE: BC = 4 (OTF) DO n DO n+1 DO n+2 DO n+3 DO n+4 DO n+5 DO n+6 DO n+7 DI b DI b+1 DI b+2 DI b+3 CRC DQ x4, BL = 8 CRC WL = 9 DQ x8/X16, BL = 8 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data CRC Don’t Care 1. BL = 8 (or BC = 4: OTF for Write), RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK. 2. DO n = data-out from column n, DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T0 and WRITE commands at T8. 5. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T8. 6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Enable. 209 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation Figure 153: READ (BC4: Fixed) to WRITE (BC4: Fixed) with 1tCK Preamble and Write CRC in Same or Different Bank Group T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command READ tWR READ to WRITE command delay = RL +BL/2 - WL + 2 tCK Bank Group Address Address tWTR 2 Clocks BGa BGa or BGb Bank Col n Bank Col b tRPRE tWPST tWPRE tRPST DQS_t, DQS_c RL = 11 DQ x4, BC = 4 (Fixed) DO n DO n+1 DO n+2 DO n+3 DI b DI b+1 DI b+2 DI b+3 CRC DO n DO n+1 DO n+2 DO n+3 DI b DI b+1 DI b+2 DI b+3 CRC CRC WL = 9 DQ x8/X16, BC = 4 (Fixed) Time Break Notes: Transitioning Data Don’t Care 1. BC = 4 (Fixed), RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK, WL = 9 (CWL = 9, AL = 0), WRITE preamble = 1tCK. 2. DO n = data-out from column n, DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 10. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Enable. READ Operation with Command/Address Latency (CAL) Enabled Figure 154: Consecutive READ (BL8) with CAL (3tCK) and 1tCK Preamble in Different Bank Group T0 T1 T2 T3 T4 T5 T6 T7 T8 T13 T14 T15 T17 T18 T19 T21 T22 T23 DES READ DES DES DES DES DES DES DES DES DES DES CK_c CK_t tCAL Command w/o CS_n tCAL =3 DES DES READ DES DES =3 CS_n tCCD_S Bank Group Address Address =4 BGa BGb Bank Col n Bank Col b tRPST tRPRE DQS_t, DQS_c RL = 11 DI n DQ DI n+1 DI n+2 DI n+5 DI n+6 DI n+7 DI b DI b+1 DI b+2 DI b+5 DI b+6 DI b+7 RL = 11 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK. 210 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM READ Operation 2. DI n (or b) = data-in from column n (or b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T3 and T7. 5. CA parity = Enable, CS to CA latency = Enable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. 6. Enabling CAL mode does not impact ODT control timings. The same timing relationship relative to the command/address bus as when CAL is disabled should be maintained. Figure 155: Consecutive READ (BL8) with CAL (4tCK) and 1tCK Preamble in Different Bank Group T0 T1 T2 T3 T4 T5 READ DES DES T6 T7 T8 T14 T15 T16 T18 T19 T21 T22 T23 T24 READ DES DES DES DES DES DES DES DES DES DES CK_c CK_t tCAL Command w/o CS_n DES tCAL =4 DES =4 DES CS_n tCCD_S Bank Group Address Address =4 BGa BGb Bank Col n Bank Col b tRPST tRPRE DQS_t, DQS_c RL = 11 DI n DQ DI n+1 DI n+2 DI n+5 DI n+6 DI n+7 DI b DI b+1 DI b+2 DI b+5 DI b+6 DI b+7 RL = 11 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL = 8, RL = 11 (CL = 11, AL = 0), READ preamble = 1tCK. 2. DI n (or b) = data-in from column n (or b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during READ commands at T3 and T8. 5. CA parity = Enable, CS to CA latency = Enable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. 6. Enabling CAL mode does not impact ODT control timings. The same timing relationship relative to the command/address bus as when CAL is disabled should be maintained. 211 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation WRITE Operation Write Timing Definitions The write timings shown in the following figures are applicable in normal operation mode, that is, when the DLL is enabled and locked. Write Timing – Clock-to-Data Strobe Relationship The clock-to-data strobe relationship is shown below and is applicable in normal operation mode, that is, when the DLL is enabled and locked. Rising data strobe edge parameters: • tDQSS (MIN) to tDQSS (MAX) describes the allowed range for a rising data strobe edge relative to CK. • tDQSS is the actual position of a rising strobe edge relative to CK. • tDQSH describes the data strobe high pulse width. • tWPST strobe going to HIGH, nondrive level (shown in the postamble section of the graphic below). Falling data strobe edge parameters: • tDQSL describes the data strobe low pulse width. • tWPRE strobe going to LOW, initial drive level (shown in the preamble section of the graphic below). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 212 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 156: Write Timing Definition CK_c CK_t Command3 T0 T1 T2 T7 T8 T9 T10 WRITE DES DES DES DES DES DES T11 T12 T13 T14 DES DES DES DES WL = AL + CWL Address4 Bank, Col n tDQSS tDSH tDQSS tDSH tDSH tDSH tWPSTaa tWPRE(1nCK) (MIN) DQS_t, DQS_c tDQSL tDQSH tDQSH tDQSL tDQSH tDQSH tDQSL tDQSH tDQSL tDSS DQ2 tDSS DIN n tDSS DIN n+ 2 tDSS DIN n+ 4 DIN n+ 3 tDSH tDQSS tDQSL (MIN) DIN n+ 6 tDSH DIN n+ 7 tDSH tDSH tWPST tWPRE(1nCK) (nominal) (MIN) tDSS (MIN) DQS_t, DQS_c tDQSL tDQSH tDQSH tDQSL tDQSH tDQSL tDQSH tDQSL tDQSH tDQSL (MIN) tDSS DQ2 tDSS tDSS DIN n+ 2 DIN n DIN n+ 3 tDSS DIN n+ 4 (MIN) tDSS DIN n+ 6 DIN n+ 7 tDQSS tDSH tDQSS tDSH tDSH tDSH tWPRE(1nCK) (MAX) tWPST (MIN) tDQSL (MIN) DQS_t, DQS_c tDQSL tDQSH tDQSH tDQSL tDQSH tDQSL tDQSH tDQSL tDQSH (MIN) tDSS tDSS DIN n+ 2 DIN n DQ2 tDSS DIN n+ 3 tDSS DIN n+ 4 tDSS DIN n+ 6 DIN n+ 7 DM_n Time Break Notes: Transitioning Data Don’t Care 1. BL8, WL = 9 (AL = 0, CWL = 9). 2. DINn = data-in from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0. 5. tDQSS must be met at each rising clock edge. Write Timing – Data Strobe-to-Data Relationship The DQ input receiver uses a compliance mask (Rx) for voltage and timing as shown in the figure below. The receiver mask (Rx mask) defines the area where the input signal must not encroach in order for the DRAM input receiver to be able to successfully capture a valid input signal. The Rx mask is not the valid data-eye. TdiVW and V diVW define the absolute maximum Rx mask. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 213 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 157: Rx Compliance Mask VDIVW Rx Mask VCENTDQ,midpoint TdiVW VCENTDQ,midpoint is defined as the midpoint between the largest V REFDQ voltage level and the smallest V REFDQ voltage level across all DQ pins for a given DRAM. Each DQ pin's VREFDQ is defined by the center (widest opening) of the cumulative data input eye as depicted in the following figure. This means a DRAM's level variation is accounted for within the DRAM Rx mask. The DRAM V REFDQ level will be set by the system to account for RON and ODT settings. Figure 158: VCENT_DQ VREFDQ Voltage Variation DQx DQy (smallest VREFDQ Level) DQz (largest VREFDQ Level) VCENTDQz VCENTDQx VCENTDQ,midpoint VCENTDQy VREF variation (component) The following figure shows the Rx mask requirements both from a midpoint-to-midpoint reference (left side) and from an edge-to-edge reference. The intent is not to add any new requirement or specification between the two but rather how to convert the relationship between the two methodologies. The minimum data-eye shown in the composite view is not actually obtainable due to the minimum pulse width requirement. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 214 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 159: Rx Mask DQ-to-DQS Timings DQS, DQs Data-In at DRAM Ball DQS, DQs Data-In at DRAM Ball Rx Mask Rx Mask – Alternative View DQS_c DQS_c DQS_t DQS_t VdiVW DRAMa DQx–z Rx Mask DRAMa DQx–z VdiVW 0.5 × TdiVW 0.5 × TdiVW 0.5 × TdiVW 0.5 × TdiVW Rx Mask TdiVW TdiVW tDQS2DQ +0.5 × TdiVW DRAMb DQy Rx Mask VdiVW Rx Mask TdiVW tDQ2DQ VdiVW DRAMb DQz tDQ2DQ Rx Mask DRAMb DQz Rx Mask VdiVW DRAMb DQy VdiVW tDQS2DQ TdiVW tDQ2DQ tDQ2DQ Rx Mask TdiVW tDQ2DQ VdiVW DRAMc DQy Rx Mask DRAMc DQz DRAMc DQy Rx Mask TdiVW VdiVW Rx Mask VdiVW DRAMc DQz +0.5 × TdiVW VdiVW tDQS2DQ tDQS2DQ tDQ2DQ Notes: 1. DQx represents an optimally centered mask. DQy represents earliest valid mask. DQz represents latest valid mask. 2. DRAMa represents a DRAM without any DQS/DQ skews. DRAMb represents a DRAM with early skews (negative tDQS2DQ). DRAMc represents a DRAM with delayed skews (positive tDQS2DQ). 3. This figure shows the skew allowed between DRAM-to-DRAM and between DQ-to-DQ for a DRAM. Signals assume data is center-aligned at DRAM latch. TdiPW is not shown; composite data-eyes shown would violate TdiPW. VCENTDQ,midpoint is not shown but is assumed to be midpoint of VdiVW. The previous figure shows the basic Rx mask requirements. Converting the Rx mask requirements to a classical DQ-to-DQS relationship is shown in the following figure. It should become apparent that DRAM write training is required to take full advantage of the Rx mask. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 215 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 160: Rx Mask DQ-to-DQS DRAM-Based Timings DQS, DQs Data-In at DRAM Ball DQS, DQs Data-In at DRAM Ball Rx Mask vs. Composite Data-Eye Rx Mask vs. UI Data-Eye DQS_c DQS_c DQS_t tDSx TdiPW Rx Mask VdiVW DRAMa DQx , y, z TdiVW DRAMa DQx–z TdiPW tDHx Rx Mask VdiVW DQS_t TdiVW TdiPW tDSy tDHy DRAMb DQz Rx Mask TdiVW tDQ2DQ Rx Mask tDQ2DQ TdiVW VdiVW DRAMb DQy VdiVW *Skew TdiPW tDSz tDHz DRAMc DQz tDQ2DQ Rx Mask Rx Mask TdiVW TdiVW tDQ2DQ VdiVW DRAMc DQy VdiVW *Skew TdiPW Notes: 1. DQx represents an optimally centered mask. DQy represents earliest valid mask. DQz represents latest valid mask. 2. *Skew = tDQS2DQ + 0.5 × TdiVW DRAMa represents a DRAM without any DQS/DQ skews. DRAMb represents a DRAM with the earliest skews (negative tDQS2DQ, tDQSy > *Skew). DRAMc represents a DRAM with the latest skews (positive tDQS2DQ, tDQHz > *Skew). t 3. DS/tDH are traditional data-eye setup/hold edges at DC levels. tDS and tDH are not specified; tDH and tDS may be any value provided the pulse width and Rx mask limits are not violated. tDH (MIN) > TdiVW + tDS (MIN) + tDQ2DQ. The DDR4 SDRAM's input receivers are expected to capture the input data with an Rx mask of TdiVW provided the minimum pulse width is satisfied. The DRAM controller will have to train the data input buffer to utilize the Rx mask specifications to this maxi- PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 216 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation mum benefit. If the DRAM controller does not train the data input buffers, then the worst case limits have to be used for the Rx mask (TdiVW + 2 × tDQS2DQ), which will generally be the classical minimum ( tDS and tDH) and is required as well. Figure 161: Example of Data Input Requirements Without Training TdiVW + 2 × tDQS2DQ VdiVW VIH(DC) 0.5 × VdiVW Rx Mask VCENTDQ,midpoint 0.5 × VdiVW VIL(DC) tDS tDH 0.5 × TdiVW + tDQS2DQ 0.5 × TdiVW + tDQS2DQ DQS_c DQS_t WRITE Burst Operation The following write timing diagrams are intended to help understand each write parameter's meaning and are only examples. Each parameter will be defined in detail separately. In these write timing diagrams, CK and DQS are shown aligned, and DQS and DQ are shown center-aligned for the purpose of illustration. DDR4 WRITE command supports bursts of BL8 (fixed), BC4 (fixed), and BL8/BC4 onthe-fly (OTF); OTF uses address A12 to control OTF when OTF is enabled: • A12 = 0, BC4 (BC4 = burst chop) • A12 = 1, BL8 WRITE commands can issue precharge automatically with a WRITE with auto precharge (WRA) command, which is enabled by A10 HIGH. • WRITE command with A10 = 0 (WR) performs standard write, bank remains active after WRITE burst • WRITE command with A10 = 1 (WRA) performs write with auto precharge, bank goes into precharge after WRITE burst The DATA MASK (DM) function is supported for the x8 and x16 configurations only (the DM function is not supported on x4 devices). The DM function shares a common pin with the DBI_n and TDQS functions. The DM function only applies to WRITE operations and cannot be enabled at the same time the DBI function is enabled. • If DM_n is sampled LOW on a given byte lane, the DRAM masks the write data received on the DQ inputs. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 217 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation • If DM_n is sampled HIGH on a given byte lane, the DRAM does not mask the data and writes this data into the DRAM core. • If CRC write is enabled, then DM enabled (via MRS) will be selected between write CRC nonpersistent mode (DM disabled) and write CRC persistent mode (DM enabled). Figure 162: WRITE Burst Operation, WL = 9 (AL = 0, CWL = 9, BL8) T0 T1 T2 T7 T8 T9 WRITE DES DES DES DES DES T10 T11 T12 T13 T14 T15 T16 DES DES DES DES DES DES CK_c CK_t Command Bank Group Address BGa Address Bank Col n DES tWPST tWPRE DQS_t, DQS_c DI n DQ DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 WL = AL + CWL = 9 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL8, WL = 0, AL = 0, CWL = 9, Preamble = 1tCK. 2. DI n = Data-in from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0. 5. CA parity = Disable, CS to CA atency = Disable, Read DBI = Disable. 218 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 163: WRITE Burst Operation, WL = 19 (AL = 10, CWL = 9, BL8) T0 T1 T2 T9 T10 T11 T17 T18 T19 T20 T21 T22 T23 WRITE DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command Bank Group Address BGa Bank Col n Address tWPST tWPRE DQS_t, DQS_c DI n DQ AL = 10 DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 CWL = 9 WL = AL + CWL = 19 Time Break Notes: Transitioning Data Don’t Care 1. BL8, WL = 19, AL = 10 (CL - 1), CWL = 9, Preamble = 1tCK. 2. DI n = data-in from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable. WRITE Operation Followed by Another WRITE Operation Figure 164: Consecutive WRITE (BL8) with 1tCK Preamble in Different Bank Group T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command tWR tCCD_S Bank Group Address Address 4 Clocks =4 BGa BGb Bank Col n Bank Col b tWTR tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 9 DI n DQ DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 WL = AL + CWL = 9 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL8, AL = 0, CWL = 9, Preamble = 1tCK. 2. DI n (or b) = data-in from column n (or column b). 219 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T4. 5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable. 6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T17. Figure 165: Consecutive WRITE (BL8) with 2tCK Preamble in Different Bank Group T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command tWR tCCD_S Bank Group Address Address 4 Clocks =4 BGa BGb Bank Col n Bank Col b tWTR tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 10 DI n DQ DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 WL = AL + CWL = 10 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL8, AL = 0, CWL = 9 + 1 = 10 (see Note 7), Preamble = 2tCK. 2. DI n (or b) = data-in from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T4. 5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable. 6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T17. 7. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock greater than the lowest CWL setting supported in the applicable tCK range, which means CWL = 9 is not allowed when operating in 2tCK WRITE preamble mode. 220 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 166: Nonconsecutive WRITE (BL8) with 1tCK Preamble in Same or Different Bank Group T0 T1 T2 T3 T4 T5 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 WRITE DES DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command tWR tCCD_S/L Bank Group Address Address 4 Clocks =5 BGa BGa or BGb Bank Col n Bank Col b tWTR tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 9 DI n DQ DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 WL = AL + CWL = 9 Time Break Notes: Don’t Care Transitioning Data 1. BL8, AL = 0, CWL = 9, Preamble = 1tCK, tCCD_S/L = 5tCK. 2. DI n (or b) = data-in from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T5. 5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable. 6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T18. Figure 167: Nonconsecutive WRITE (BL8) with 2tCK Preamble in Same or Different Bank Group T0 T1 T2 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 WRITE DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command tWR tCCD_S/L Bank Group Address Address 4 Clocks =6 BGa BGa or BGb Bank Col n Bank Col b tWPRE tWTR tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 10 DI n DQ DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 WL = AL + CWL = 10 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL8, AL = 0, CWL = 9 + 1 = 10 (see Note 8), Preamble = 2tCK, tCCD_S/L = 6tCK. 2. DI n (or b) = data-in from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T6. 221 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation 5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable. 6. tCCD_S/L = 5 isn’t allowed in 2tCK preamble mode. 7. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T20. 8. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock greater than the lowest CWL setting supported in the applicable tCK range, which means CWL = 9 is not allowed when operating in 2tCK WRITE preamble mode. Figure 168: WRITE (BC4) OTF to WRITE (BC4) OTF with 1tCK Preamble in Different Bank Group T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command tWR tCCD_S Bank Group Address Address 4 Clocks =4 BGa BGb Bank Col n Bank Col b tWPST tWPRE tWTR tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 9 DI n DQ DI n+1 DI n+2 DI n+3 DI b DI b+1 DI b+2 DI b+3 WL = AL + CWL = 9 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BC4, AL = 0, CWL = 9, Preamble = 1tCK. 2. DI n (or b) = data-in from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T0 and T4. 5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable. 6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T17. 222 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 169: WRITE (BC4) OTF to WRITE (BC4) OTF with 2tCK Preamble in Different Bank Group T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES T19 CK_c CK_t Command DES tWR tCCD_S Bank Group Address Address 4 Clocks =4 BGa BGb Bank Col n Bank Col b tWPRE tWTR tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 10 DI n DQ DI n+1 DI n+2 DI n+3 DI b DI b+1 DI b+2 DI b+3 WL = AL + CWL = 10 Time Break Notes: Transitioning Data Don’t Care 1. BC4, AL = 0, CWL = 9 + 1 = 10 (see Note 7), Preamble = 2tCK. 2. DI n (or b) = data-in from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T4. 5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable. 6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T18. 7. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock greater than the lowest CWL setting supported in the applicable tCK range, which means CWL = 9 is not allowed when operating in 2tCK WRITE preamble mode. Figure 170: WRITE (BC4) Fixed to WRITE (BC4) Fixed with 1tCK Preamble in Different Bank Group T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command tWR tCCD_S Bank Group Address Address 2 Clocks =4 BGa BGb Bank Col n Bank Col b tWPST tWPRE tWTR tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 9 DI n DQ DI n+1 DI n+2 DI n+3 DI b DI b+1 DI b+2 DI b+3 WL = AL + CWL = 9 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BC4, AL = 0, CWL = 9, Preamble = 1tCK. 2. DI n (or b) = data-in from column n (or column b). 223 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 (fixed) setting activated by MR0[1:0] = 10. 5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Disable, Write CRC = Disable. 6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T15. Figure 171: WRITE (BL8) to WRITE (BC4) OTF with 1tCK Preamble in Different Bank Group T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES T19 CK_c CK_t Command DES t 4 Clocks t CCD_S = 4 Bank Group Address Address BGa BGb Bank Col n Bank Col b t t WPRE WR t WTR WPST DQS_t, DQS_c WL = AL + CWL = 9 DI n DQ DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 DI b DI b+1 DI b+2 DI b+3 WL = AL + CWL = 9 Time Break Notes: Transitioning Data Don’t Care 1. BL = 8/BC = 4, AL = 0, CL = 9, Preamble = 1tCK. 2. DI n (or b) = data-in from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during WRITE command at T0. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T4. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Disable. 6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T17. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 224 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 172: WRITE (BC4) OTF to WRITE (BL8) with 1tCK Preamble in Different Bank Group T0 T1 T2 T3 T4 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES T19 CK_c CK_t Command DES tWR tCCD_S Bank Group Address Address 4 Clocks =4 BGa BGb Bank Col n Bank Col b tWPST tWPRE tWTR tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 9 DI n DQ DI n+1 DI n+2 DI n+3 DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 WL = AL + CWL = 9 Time Break Don’t Care Transitioning Data 1. BL = 8/BC = 4, AL = 0, CL = 9, Preamble = 1tCK. 2. DI n (or b) = data-in from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T0. Notes: BL8 setting activated by MR0[1:0] = 01 and A12 = 1 during WRITE command at T4. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Disable. 6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T17. WRITE Operation Followed by READ Operation Figure 173: WRITE (BL8) to READ (BL8) with 1tCK Preamble in Different Bank Group T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T24 T25 T26 T27 T28 T29 WRITE DES DES DES DES DES DES DES DES DES READ DES DES DES DES DES DES DES CK_c CK_t Command 4 Clocks Bank Group Address Address tWTR_S BGa =2 BGb Bank Col n Bank Col b tWPST tWPRE tRPRE DQS_t, DQS_c WL = AL + CWL = 9 RL = AL + CL = 11 DI n DQ DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 DI b Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN DI b+1 DI b+2 DI b+3 Transitioning Data DI b+4 DI b+5 DI b+6 Don’t Care 1. BL = 8, WL = 9 (CWL = 9, AL = 0), CL = 11, READ preamble = 1tCK, WRITE preamble = 1tCK. 2. DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 225 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0 and READ command at T15. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. 6. The write timing parameter (tWTR_S) is referenced from the first rising clock edge after the last write data shown at T13. Figure 174: WRITE (BL8) to READ (BL8) with 1tCK Preamble in Same Bank Group T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T26 T27 T28 T29 WRITE DES DES DES DES DES DES DES DES DES DES DES READ DES DES DES DES DES CK_c CK_t Command 4 Clocks Bank Group Address Address tWTR_L BGa =4 BGa Bank Col n Bank Col b tWPST tWPRE tRPRE DQS_t, DQS_c WL = AL + CWL = 9 RL = AL + CL = 11 DI n DQ DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 DI b Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data DI b+1 DI b+2 Don’t Care 1. BL = 8, WL = 9 (CWL = 9, AL = 0), CL = 11, READ preamble = 1tCK, WRITE preamble = 1tCK. 2. DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0 and READ command at T17. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. 6. The write timing parameter (tWTR_L) is referenced from the first rising clock edge after the last write data shown at T13. 226 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 175: WRITE (BC4) OTF to READ (BC4) OTF with 1tCK Preamble in Different Bank Group T0 T1 T7 T8 T9 T10 WRITE DES DES DES DES DES T11 T12 T13 DES DES DES T14 T15 T16 T24 T25 T26 T27 T28 T29 DES READ DES DES DES DES DES DES DES CK_c CK_t Command 4 Clocks Bank Group Address Address tWTR_S =2 BGa BGb Bank Col n Bank Col b tWPST tWPRE tRPST tRPRE DQS_t, DQS_c WL = AL + CWL = 9 RL = AL + CL = 11 DI n DQ DI n+1 DI n+2 DI n+3 DI b Time Break DI b+1 DI b+2 DI b+3 Transitioning Data Don’t Care 1. BC = 4, WL = 9 (CWL = 9, AL = 0), CL = 11, READ preamble = 1tCK, WRITE preamble = 1tCK. 2. DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T0 and READ command at T15. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. 6. The write timing parameter (tWTR_S) is referenced from the first rising clock edge after the last write data shown at T13. Notes: Figure 176: WRITE (BC4) OTF to READ (BC4) OTF with 1tCK Preamble in Same Bank Group T0 T1 T7 T8 T9 T10 WRITE DES DES DES DES DES T11 T12 T13 T14 DES DES DES DES T15 T16 T17 T18 T26 T27 T28 T29 DES DES READ DES DES DES DES DES CK_c CK_t Command 4 Clocks Bank Group Address Address tWTR_L BGa =4 BGa Bank Col n Bank Col b tWPST tWPRE tRPRE DQS_t, DQS_c WL = AL + CWL = 9 RL = AL + CL = 11 DI n DQ DI n+1 DI n+2 DI n+3 DI b Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data DI b+1 DI b+2 Don’t Care 1. BC = 4, WL = 9 (CWL = 9, AL = 0), CL = 11, READ preamble = 1tCK, WRITE preamble = 1tCK. 2. DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T0 and READ command at T17. 227 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. 6. The write timing parameter (tWTR_L) is referenced from the first rising clock edge after the last write data shown at T13. Figure 177: WRITE (BC4) Fixed to READ (BC4) Fixed with 1 tCK Preamble in Different Bank Group T0 T1 T7 T8 T9 WRITE DES DES DES DES T10 T11 DES DES T12 T13 T14 T22 T23 T24 T25 T26 T27 T28 T29 DES DES DES DES DES READ DES DES DES DES DES CK_c CK_t Command 2 Clocks Bank Group Address Address tWTR_S =2 BGa BGb Bank Col n Bank Col b tWPST tWPRE tRPST tRPRE DQS_t, DQS_c WL = AL + CWL = 9 RL = AL + CL = 11 DI n DQ DI n+1 DI n+2 DI n+3 DI b DI b+1 DI b+2 DI b+3 Time Break Transitioning Data Don’t Care 1. BC = 4, WL = 9 (CWL = 9, AL = 0), CL = 11, READ preamble = 1 tCK, WRITE preamble = 1tCK. 2. DI b = data-in from column b. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 10. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. 6. The write timing parameter (tWTR_S) is referenced from the first rising clock edge after the last write data shown at T11. Notes: Figure 178: WRITE (BC4) Fixed to READ (BC4) Fixed with 1tCK Preamble in Same Bank Group T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T24 T25 T26 T27 T28 T29 WRITE DES DES DES DES DES DES DES DES DES READ DES DES DES DES DES DES DES CK_c CK_t Command 2 Clocks Bank Group Address Address tWTR_L =4 BGa BGa Bank Col n Bank Col b tWPST tWPRE tRPST tRPRE DQS_t, DQS_c WL = AL + CWL = 9 RL = AL + CL = 11 DI n DQ DI n+1 DI n+2 DI n+3 DI b Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN DI b+1 DI b+2 DI b+3 Transitioning Data Don’t Care 1. BC = 4, WL = 9 (CWL = 9, AL = 0), C L = 11, READ preamble = 1tCK, WRITE preamble = 1tCK. 2. DI b = data-in from column b. 228 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 10. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write DBI = Disable, Write CRC = Disable. 6. The write timing parameter (tWTR_L) is referenced from the first rising clock edge after the last write data shown at T11. WRITE Operation Followed by PRECHARGE Operation The minimum external WRITE command to PRECHARGE command spacing is equal to WL (AL + CWL) plus either 4tCK (BL8/BC4-OTF) or 2tCK (BC4-fixed) plus tWR. The minimum ACT to PRE timing, tRAS, must be satisfied as well. Figure 179: WRITE (BL8/BC4-OTF) to PRECHARGE with 1tCK Preamble T0 T1 T2 WRITE DES DES T3 T4 T7 T8 T9 T10 DES DES DES DES DES DES T11 T12 T13 T14 T22 DES DES DES DES DES T23 T24 T25 DES DES PRE T26 CK_c CK_t Command WL = AL + CWL = 9 tWR 4 Clocks BGa, Bank b Col n DES tRP = 12 BGa, Bank b (or all) Address BC4 (OTF) Opertaion DQS_t, DQS_c DQ DI n DI n+1 DI n+2 DI n+3 DI n DI n+1 DI n+2 DI n+3 BL8 Opertaion DQS_t, DQS_c DQ DI n+4 DI n+5 DI n+6 DI n+7 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL = 8 with BC4-OTF, WL = 9 (CWL = 9, AL = 0 ), Preamble = 1tCK, tWR = 12. 2. DI n = data-in from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T0. BL8 setting activated by MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, CRC = Disable. 6. The write recovery time (tWR) is referenced from the first rising clock edge after the last write data shown at T13. tWR specifies the last burst WRITE cycle until the PRECHARGE command can be issued to the same bank. 229 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 180: WRITE (BC4-Fixed) to PRECHARGE with 1tCK Preamble T0 T1 T2 WRITE DES DES T3 T4 T7 T8 T9 DES DES DES DES DES T10 T11 T12 T13 DES DES DES DES T14 T22 T23 DES DES PRE T24 T25 T26 DES DES DES CK_c CK_t Command WL = AL + CWL = 9 tWR 2 Clocks tRP = 12 BGa, Bank b Col n BGa, Bank b (or all) Address BC4 (Fixed) Opertaion DQS_t, DQS_c DI n DQ DI n+1 DI n+2 DI n+3 Time Break Notes: Transitioning Data Don’t Care 1. BC4 = fixed, WL = 9 (CWL = 9, AL = 0 ), Preamble = 1tCK, tWR = 12. 2. DI n = data-in from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 10. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, CRC = Disable. 6. The write recovery time (tWR) is referenced from the first rising clock edge after the last write data shown at T11. tWR specifies the last burst WRITE cycle until the PRECHARGE command can be issued to the same bank. Figure 181: WRITE (BL8/BC4-OTF) to Auto PRECHARGE with 1tCK Preamble T0 T1 T2 WRITE DES DES T3 T4 T7 T8 T9 T10 DES DES DES DES DES DES T11 T12 T13 T14 T22 DES DES DES DES DES T23 T24 T25 DES DES DES T26 CK_c CK_t Command WL = AL + CWL = 9 tWR 4 Clocks DES tRP = 12 BGa, Bank b Col n Address BC4 (OTF) Opertaion DQS_t, DQS_c DQ DI n DI n+1 DI n+2 DI n+3 DI n DI n+1 DI n+2 DI n+3 BL8 Opertaion DQS_t, DQS_c DQ DI n+4 DI n+5 DI n+6 DI n+7 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL = 8 with BC4-OTF, WL = 9 (CWL = 9, AL = 0 ), Preamble = 1tCK, tWR = 12. 2. DI n = data-in from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T0. BL8 setting activated by MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, CRC = Disable. 230 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation 6. The write recovery time (tWR) is referenced from the first rising clock edge after the last write data shown at T13. tWR specifies the last burst WRITE cycle until the PRECHARGE command can be issued to the same bank. Figure 182: WRITE (BC4-Fixed) to Auto PRECHARGE with 1tCK Preamble T0 T1 T2 WRITE DES DES T3 T4 T7 T8 T9 DES DES DES DES DES T10 T11 T12 T13 DES DES DES DES T14 T22 T23 T24 DES DES DES DES T25 T26 DES DES CK_c CK_t Command WL = AL + CWL = 9 tWR 2 Clocks tRP = 12 BGa, Bank b Col n Address BC4 (Fixed) Opertaion DQS_t, DQS_c DI n DQ DI n+1 DI n+2 DI n+3 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BC4 = fixed, WL = 9 (CWL = 9, AL = 0 ), Preamble = 1tCK, tWR = 12. 2. DI n = data-in from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 10. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, CRC = Disable. 6. The write recovery time (tWR) is referenced from the first rising clock edge after the last write data shown at T11. tWR specifies the last burst WRITE cycle until the PRECHARGE command can be issued to the same bank. 231 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation WRITE Operation with WRITE DBI Enabled Figure 183: WRITE (BL8/BC4-OTF) with 1tCK Preamble and DBI T0 T1 T2 WRITE DES DES T3 T4 T5 T6 T7 T8 T9 T10 DES DES DES DES DES DES DES DES T11 T12 T13 T14 DES DES DES DES T15 T16 T17 DES DES DES CK_c CK_t Command WL = AL + CWL = 9 tWR 4 Clocks tWTR Address BGa Address Bank, Col n BC4 (OTF) Opertaion DQS_t, DQS_c DQ DI n DI n+1 DI n+2 DI n+3 DBI_n DI n DI n+1 DI n+2 DI n+3 DQ DI n DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 DBI_n DI n DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 BL8 Opertaion DQS_t, DQS_c Transitioning Data Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. BL = 8 with BC4-OTF, WL = 9 (CWL = 9, AL = 0 ), Preamble = 1tCK. 2. DI n = data-in from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE command at T0. BL8 setting activated by MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0. 5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Enabled, Write CRC = Disabled. 6. The write recovery time (tWR_DBI) is referenced from the first rising clock edge after the last write data shown at T13. 232 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 184: WRITE (BC4-Fixed) with 1tCK Preamble and DBI T0 T1 T2 WRITE DES DES T3 T4 T5 T6 T7 T8 T9 DES DES DES DES DES DES DES T10 T11 T12 T13 T14 DES DES DES DES DES T15 T16 T17 DES DES DES CK_c CK_t Command WL = AL + CWL = 9 tWR 2 Clocks tWTR Address BGa Address Bank, Col n BC4 (Fixed) Opertaion DQS_t, DQS_c DQ DI n DI n+1 DI n+2 DI n+3 DBI_n DI n DI n+1 DI n+2 DI n+3 Transitioning Data Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. BC4 = fixed, WL = 9 (CWL = 9, AL = 0 ), Preamble = 1tCK. 2. DI n = data-in from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 10. 5. CA parity = Disable, CS to CA latency = Disable, Write DBI = Enabled, Write CRC = Disabled. 233 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation WRITE Operation with CA Parity Enabled Figure 185: Consecutive Write (BL8) with 1tCK Preamble and CA Parity in Different Bank Group T0 T1 T2 T3 T4 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 T22 T23 WRITE DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES CK_c CK_t Command tWR tCCD_S Bank Group Address 4 Clocks =4 BGa BGb Address Bank Col n Bank Col b Parity Valid Valid tWTR tWPST tWPRE DQS_t, DQS_c WL = PL + AL + CWL = 13 DI n DQ DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 WL = PL + AL + CWL = 13 Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL = 8, WL = 9 (CWL = 13, AL = 0 ), Preamble = 1tCK. 2. DI n = data-in from column n. 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T4. 5. CA parity = Enable, CS to CA latency = Disable, Write DBI = Enabled, Write CRC = Disable. 6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T21. 234 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation WRITE Operation with Write CRC Enabled Figure 186: Consecutive WRITE (BL8/BC4-OTF) with 1tCK Preamble and Write CRC in Same or Different Bank Group T0 T1 T2 T3 T4 T5 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 WRITE DES DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES T19 CK_c CK_t Command DES tWR tCCD_S/L Bank Group Address Address 4 Clocks =5 BGa BGa or BGb Bank Col n Bank Col b tWTR tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 9 DI n DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 CRC DI n DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 CRC DQ x4, BC = 4 (OTF) DI n DI n+1 DI n+2 DI n+3 CRC DQ x8/X16, BC = 4 (OTF) DI n DI n+1 DI n+2 DI n+3 CRC DQ x4, BL = 8 CRC DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 CRC DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 CRC DI b DI b+1 DI b+2 DI b+3 CRC DI b DI b+1 DI b+2 DI b+3 CRC CRC WL = AL + CWL = 9 DQ x8/X16, BL = 8 CRC Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data CRC Don’t Care 1. BL8/BC4-OTF, AL = 0, CWL = 9, Preamble = 1tCK, tCDD_S/L = 5tCK. 2. DI n (or b) = data-in from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T5. 5. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T0 and T5. 6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Enable. 7. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T18. 235 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 187: Consecutive WRITE (BC4-Fixed) with 1tCK Preamble and Write CRC in Same or Different Bank Group T0 T1 T2 T3 T4 T5 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 WRITE DES DES DES DES WRITE DES DES DES DES DES DES DES DES DES DES T18 T19 DES DES CK_c CK_t Command tWR tCCD_S/L Bank Group Address Address 2 Clocks =5 BGa BGa or BGb Bank Col n Bank Col b tWTR tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 9 DQ x4, BC = 4 (Fixed) DI n DI n+1 DI n+2 DI n+3 CRC DI n DI n+1 DI n+2 DI n+3 CRC CRC DI b DI b+1 DI b+2 DI b+3 CRC DI b DI b+1 DI b+2 DI b+3 CRC CRC WL = AL + CWL = 9 DQ x8/X16, BC = 4 (Fixed) Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BC4-fixed, AL = 0, CWL = 9, Preamble = 1tCK, tCDD_S/L = 5tCK. 2. DI n (or b) = data-in from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BC4 setting activated by MR0[1:0] = 10 during WRITE commands at T0 and T5. 5. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Enable, DM = Disable. 6. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T16. 236 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 188: Nonconsecutive WRITE (BL8/BC4-OTF) with 1tCK Preamble and Write CRC in Same or Different Bank Group T0 T1 T5 T6 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 WRITE DES DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES T20 CK_c CK_t Command DES tWR tCCD_S/L Bank Group Address Address 4 Clocks =7 BGa BGa or BGb Bank Col n Bank Col b tWTR tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 10 DI n DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 CRC DI n DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 CRC DQ x4, BC = 4 (OTF) DI n DI n+1 DI n+2 DI n+3 CRC DQ x8/X16, BC = 4 (OTF) DI n DI n+1 DI n+2 DI n+3 CRC DQ x4, BL = 8 CRC DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 CRC DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 CRC DI b DI b+1 DI b+2 DI b+3 CRC DI b DI b+1 DI b+2 DI b+3 CRC CRC WL = AL + CWL = 10 DQ x8/X16, BL = 8 CRC Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data CRC Don’t Care 1. BL8/BC4-OTF, AL = 0, CWL = 9, Preamble = 1tCK, tCDD_S/L = 6tCK. 2. DI n (or b) = data-in from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T6. 5. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T0 and T6. 6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Enable, DM = Disable. 7. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T19. 237 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 189: Nonconsecutive WRITE (BL8/BC4-OTF) with 2tCK Preamble and Write CRC in Same or Different Bank Group T0 T1 T7 T8 T9 T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T20 T21 WRITE DES WRITE DES DES DES DES DES DES DES DES DES DES DES DES DES DES T22 CK_c CK_t Command DES tWR tCCD_S/L Bank Group Address Address 4 Clocks =7 BGa BGa or BGb Bank Col n Bank Col b tWPRE tWTR tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 10 DI n DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 CRC DI n DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 CRC DQ x4, BC = 4 (OTF) DI n DI n+1 DI n+2 DI n+3 CRC DQ x8/X16, BC = 4 (OTF) DI n DI n+1 DI n+2 DI n+3 CRC DQ x4, BL = 8 CRC DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 CRC DI b DI b+1 DI b+2 DI b+3 DI b+4 DI b+5 DI b+6 DI b+7 CRC DI b DI b+1 DI b+2 DI b+3 CRC DI b DI b+1 DI b+2 DI b+3 CRC CRC WL = AL + CWL = 10 DQ x8/X16, BL = 8 CRC Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data CRC Don’t Care 1. BL8/BC4-OTF, AL = 0, CWL = 9 + 1 = 10 (see Note 9), Preamble = 2tCK, tCDD_S/L = 7tCK (see Note 7). 2. DI n (or b) = data-in from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE commands at T0 and T7. 5. BC4 setting activated by MR0[1:0] = 01 and A12 = 0 during WRITE commands at T0 and T7. 6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Enable, DM = Disable. 7. tCDD_S/L = 6tCK is not allowed in 2tCK preamble mode. 8. The write recovery time (tWR) and write timing parameter (tWTR) are referenced from the first rising clock edge after the last write data shown at T21. 9. When operating in 2tCK WRITE preamble mode, CWL may need to be programmed to a value at least 1 clock greater than the lowest CWL setting supported in the applicable tCK range. That means CWL = 9 is not allowed when operating in 2tCK WRITE preamble mode. 238 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM WRITE Operation Figure 190: WRITE (BL8/BC4-OTF/Fixed) with 1tCK Preamble and Write CRC in Same or Different Bank Group T0 T1 T2 T6 T7 T8 T9 T10 T11 T12 T13 T14 WRITE DES DES DES DES DES DES DES DES DES DES DES T15 T16 T17 T18 T19 T20 DES DES DES DES DES DES CK_c CK_t Command tWR_CRC_DM 4 Clocks Bank Group Address Address tWTR_S_CRC_DM/tWTR_L_CRC_DM BGa Bank Col n tWPST tWPRE DQS_t, DQS_c WL = AL + CWL = 9 DQ x4, BL = 8 DI n DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 CRC DQ x8/X16, BL = 8 DI n DI n+1 DI n+2 DI n+3 DI n+4 DI n+5 DI n+6 DI n+7 CRC DM n DM n+1 DM n+2 DM n+3 DM n+4 DM n+5 DM n+6 DM n+7 DQ x4, BC = 4 (OTF/Fixed) DI n DI n+1 DI n+2 DI n+3 CRC DQ x8/X16, BC = 4 (OTF/Fixed) DI n DI n+1 DI n+2 DI n+3 CRC DM n DM n+1 DM n+2 DM n+3 DMx4/x8/x16 BL = 8 DM x4/x8/x16 BC = 4 (OTF / Fixed) CRC CRC Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Transitioning Data Don’t Care 1. BL8/BC4, AL = 0, CWL = 9, Preamble = 1tCK. 2. DI n (or b) = data-in from column n (or column b). 3. DES commands are shown for ease of illustration; other commands may be valid at these times. 4. BL8 setting activated by either MR0[1:0] = 00 or MR0[1:0] = 01 and A12 = 1 during WRITE command at T0. 5. BC4 setting activated by either MR0[1:0] = 10 or MR0[1:0] = 01 and A12 = 0 during WRITE command at T0. 6. CA parity = Disable, CS to CA latency = Disable, Read DBI = Disable, Write CRC = Enable, DM = Enable. 7. The write recovery time (tWR_CRC_DM) and write timing parameter (tWTR_S_CRC_DM/ tWTR_L_CRC_DM) are referenced from the first rising clock edge after the last write data shown at T13. 239 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Write Timing Violations Write Timing Violations Motivation Generally, if timing parameters are violated, a complete reset/initialization procedure has to be initiated to make sure that the device works properly. However, for certain minor violations, it is desirable that the device is guaranteed not to "hang up" and that errors are limited to that specific operation. A minor violation does not include a major timing violation (for example, when a DQS strobe misses in the tDQSCK window). For the following, it will be assumed that there are no timing violations with regard to the WRITE command itself (including ODT, and so on) and that it does satisfy all timing requirements not mentioned below. Data Setup and Hold Violations If the data-to-strobe timing requirements (tDS, tDH) are violated, for any of the strobe edges associated with a WRITE burst, then wrong data might be written to the memory location addressed with this WRITE command. In the example, the relevant strobe edges for WRITE Burst A are associated with the clock edges: T5, T5.5, T6, T6.5, T7, T7.5, T8, and T8.5. Subsequent reads from that location might result in unpredictable read data; however, the device will work properly otherwise. Strobe-to-Strobe and Strobe-to-Clock Violations If the strobe timing requirements (tDQSH, tDQSL, tWPRE, tWPST) or the strobe to clock timing requirements (tDSS, tDSH, tDQSS) are violated, for any of the strobe edges associated with a WRITE burst, then wrong data might be written to the memory location addressed with the offending WRITE command. Subsequent reads from that location might result in unpredictable read data; however, the device will work properly otherwise with the following constraints: • Both write CRC and data burst OTF are disabled; timing specifications other than tDQSH, tDQSL, tWPRE, tWPST, tDSS, tDSH, tDQSS are not violated. • The offending write strobe (and preamble) arrive no earlier or later than six DQS transition edges from the WRITE latency position. • A READ command following an offending WRITE command from any open bank is allowed. • One or more subsequent WR or a subsequent WRA (to same bank as offending WR) may be issued tCCD_L later, but incorrect data could be written. Subsequent WR and WRA can be either offending or non-offending writes. Reads from these writes may provide incorrect data. • One or more subsequent WR or a subsequent WRA (to a different bank group) may be issued tCCD_S later, but incorrect data could be written. Subsequent WR and WRA can be either offending or non-offending writes. Reads from these writes may provide incorrect data. • After one or more precharge commands (PRE or PREA) are issued to the device after an offending WRITE command and all banks are in precharged state (idle state), a subsequent, non-offending WR or WRA to any open bank will be able to write correct data. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 240 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM ZQ CALIBRATION Commands ZQ CALIBRATION Commands A ZQ CALIBRATION command is used to calibrate DRAM RON and ODT values. The device needs a longer time to calibrate the output driver and on-die termination circuits at initialization and a relatively smaller time to perform periodic calibrations. The ZQCL command is used to perform the initial calibration during the power-up initialization sequence. This command may be issued at any time by the controller depending on the system environment. The ZQCL command triggers the calibration engine inside the DRAM and, after calibration is achieved, the calibrated values are transferred from the calibration engine to DRAM I/O, which is reflected as an updated output driver and ODT values. The first ZQCL command issued after reset is allowed a timing period of tZQinit to perform the full calibration and the transfer of values. All other ZQCL commands except the first ZQCL command issued after reset are allowed a timing period of tZQoper. The ZQCS command is used to perform periodic calibrations to account for voltage and temperature variations. A shorter timing window is provided to perform the calibration and transfer of values as defined by timing parameter tZQCS. One ZQCS command can effectively correct a minimum of 0.5 % (ZQ correction) of RON and RTT impedance error within 64 nCK for all speed bins assuming the maximum sensitivities specified in the Output Driver and ODT Voltage and Temperature Sensitivity tables. The appropriate interval between ZQCS commands can be determined from these tables and other application-specific parameters. One method for calculating the interval between ZQCS commands, given the temperature (Tdriftrate) and voltage (Vdriftrate) drift rates that the device is subjected to in the application, is illustrated. The interval could be defined by the following formula: ZQcorrection R(Tsens × Tdriftrate) + (Vsens × Vdriftrate) Where T sens = MAX(dRTTdT, dRONdTM) and V sens = MAX(dRTTdV, dRONdVM) define the temperature and voltage sensitivities. For example, if T sens = 1.5%/°C, V sens = 0.15%/mV, T driftrate = 1 °C/sec and V driftrate = 15 mV /sec, then the interval between ZQCS commands is calculated as: 0.5 = 0.133 ≈128ms (1.5 × 1) + (0.15 × 15) No other activities should be performed on the DRAM channel by the controller for the duration of tZQinit, tZQoper, or tZQCS. The quiet time on the DRAM channel allows accurate calibration of output driver and on-die termination values. After DRAM calibration is achieved, the device should disable the ZQ current consumption path to reduce power. All banks must be precharged and tRP met before ZQCL or ZQCS commands are issued by the controller. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 241 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM ZQ CALIBRATION Commands ZQ CALIBRATION commands can also be issued in parallel to DLL lock time when coming out of self refresh. Upon self refresh exit, the device will not perform an I/O calibration without an explicit ZQ CALIBRATION command. The earliest possible time for a ZQ CALIBRATION command (short or long) after self refresh exit is tXSF. In systems that share the ZQ resistor between devices, the controller must not allow any overlap of tZQoper, tZQinit, or tZQCS between the devices. Figure 191: ZQ Calibration Timing T0 T1 Ta0 Ta1 Ta2 Ta3 Tb0 Tb1 Tc0 Tc1 Tc2 ZQCL DES DES DES Valid Valid ZQCS DES DES DES Valid Address Valid Valid Valid A10 Valid Valid Valid Valid Valid Valid Valid Valid Valid CK_c CK_t Command CKE Note 1 Note 2 ODT DQ Bus High-Z or RTT(Park) Activities High-Z or RTT(Park) Activities Note 3 tZQinit_tZQoper tZQCS Time Break Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Don’t Care 1. CKE must be continuously registered HIGH during the calibration procedure. 2. On-die termination must be disabled via the ODT signal or MRS during the calibration procedure or the DRAM will automatically disable RTT1. 3. All devices connected to the DQ bus should be High-Z during the calibration procedure. 242 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM On-Die Termination On-Die Termination On-die termination (ODT) is a feature that enables the device to change termination resistance for each DQ, DQS, and DM_n signal for x4 and x8 configurations (and TDQS for the x8 configuration, when enabled via A11 = 1 in MR1) via the ODT control pin, WRITE command, or default parking value with MR setting. For the x16 configuration, ODT is applied to each DQU, DQL, DQSU, DQSL, DMU_n, and DML_n signal. The ODT feature is designed to improve the signal integrity of the memory channel by allowing the DRAM controller to independently change termination resistance for any or all DRAM devices. More details about ODT control modes and ODT timing modes can be found further along in this document. The ODT feature is turned off and not supported in self refresh mode. Figure 192: Functional Representation of ODT ODT To other circuitry such as RCV, ... VDDQ RTT Switch DQ, DQS, DM, TDQS The switch is enabled by the internal ODT control logic, which uses the external ODT pin and other control information. The value of R TT is determined by the settings of mode register bits (see Mode Register). The ODT pin will be ignored if the mode register MR1 is programmed to disable RTT(NOM) [MR1[9,6,2] = 0,0,0] and in self refresh mode. ODT Mode Register and ODT State Table The ODT mode of the DDR4 device has four states: data termination disable, RTT(NOM), RTT(WR), and RTT(Park). The ODT mode is enabled if any of MR1[10:8] (R TT(NOM)), MR2[11:9] (RTT(WR)), or MR5[8:6] (RTT(Park)) are non-zero. When enabled, the value of RTT is determined by the settings of these bits. RTT control of each RTT condition is possible with a WR or RD command and ODT pin. • RTT(WR): The DRAM (rank) that is being written to provide termination regardless of ODT pin status (either HIGH or LOW). • RTT(NOM): DRAM turns ON RTT(NOM) if it sees ODT asserted HIGH (except when ODT is disabled by MR1). • RTT(Park): Default parked value set via MR5 to be enabled and RTT(NOM) is not turned on. • The Termination State Table that follows shows various interactions. The RTT values have the following priority: • • • • PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Data termination disable RTT(WR) RTT(NOM) RTT(Park) 243 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM ODT Mode Register and ODT State Table Table 67: Termination State Table Case RTT(Park) RTT(NOM)1 RTT(WR)2 ODT Pin ODT READS3 ODT Standby ODT WRITES A4 Disabled Disabled Disabled Don't Care Off (High-Z) Off (High-Z) Off (High-Z) Enabled Don't Care Off (High-Z) Off (High-Z) RTT(WR) RTT(Park) RTT(Park) B5 Enabled Disabled Disabled Don't Care Off (High-Z) Enabled Don't Care Off (High-Z) RTT(Park) RTT(WR) C6 Disabled Enabled Disabled Low Off (High-Z) Off (High-Z) Off (High-Z) High Off (High-Z) RTT(NOM) RTT(NOM) Low Off (High-Z) Off (High-Z) RTT(WR) High Off (High-Z) RTT(NOM) RTT(WR) Low Off (High-Z) RTT(Park) RTT(Park) High Off (High-Z) RTT(NOM) RTT(NOM) Low Off (High-Z) RTT(Park) RTT(WR) High Off (High-Z) RTT(NOM) RTT(WR) Enabled D6 Enabled Enabled Disabled Enabled Notes: 1. If RTT(NOM) MR is disabled, power to the ODT receiver will be turned off to save power. 2. If RTT(WR) is enabled, RTT(WR) will be activated by a WRITE command for a defined period time independent of the ODT pin and MR setting of RTT(Park)/RTT(NOM). This is described in the Dynamic ODT section. 3. When a READ command is executed, the DRAM termination state will be High-Z for a defined period independent of the ODT pin and MR setting of RTT(Park)/RTT(NOM). This is described in the ODT During Read section. 4. Case A is generally best for single-rank memories. 5. Case B is generally best for dual-rank, single-slotted memories. 6. Case C and Case D are generally best for multi-slotted memories. ODT Read Disable State Table Upon receiving a READ command, the DRAM driving data disables ODT after RL - (2 or 3) clock cycles, where 2 = 1tCK preamble mode and 3 = 2tCK preamble mode. ODT stays off for a duration of BL/2 + (2 or 3) + (0 or 1) clock cycles, where 2 = 1tCK preamble mode, 3 = 2tCK preamble mode, 0 = CRC disabled, and 1 = CRC enabled. Table 68: Read Termination Disable Window Preamble CRC Start ODT Disable After Read Duration of ODT Disable 1tCK Disabled RL - 2 BL/2 + 2 Enabled RL - 2 BL/2 + 3 2tCK Disabled RL - 3 BL/2 + 3 Enabled RL - 3 BL/2 + 4 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 244 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Synchronous ODT Mode Synchronous ODT Mode Synchronous ODT mode is selected whenever the DLL is turned on and locked. Based on the power-down definition, these modes include the following: • • • • • Any bank active with CKE HIGH Refresh with CKE HIGH Idle mode with CKE HIGH Active power-down mode (regardless of MR1 bit A10) Precharge power-down mode In synchronous ODT mode, RTT(NOM) will be turned on DODTLon clock cycles after ODT is sampled HIGH by a rising clock edge and turned off DODTLoff clock cycles after ODT is registered LOW by a rising clock edge. The ODT latency is determined by the programmed values for: CAS WRITE latency (CWL), additive latency (AL), and parity latency (PL), as well as the programmed state of the preamble. ODT Latency and Posted ODT The ODT latencies for synchronous ODT mode are summarized in the table below. For details, refer to the latency definitions. Table 69: ODT Latency at DDR4-1600/-1866/-2133/-2400/-2666/-3200 Applicable when write CRC is disabled Symbol Parameter 1tCK Preamble 2tCK Preamble Unit tCK DODTLon Direct ODT turn-on latency CWL + AL + PL - 2 CWL + AL + PL - 3 DODTLoff Direct ODT turn-off latency CWL + AL + PL - 2 CWL + AL + PL - 3 RODTLoff READ command to internal ODT turn-off latency CL + AL + PL - 2 CL + AL + PL - 3 RODTLon4 READ command to RTT(Park) turn-on latency in BC4-fixed RODTLoff + 4 RODTLoff + 5 RODTLon8 READ command to RTT(Park) turn-on latency in BL8/BC4-OTF RODTLoff + 6 RODTLoff + 7 ODTH4 ODT Assertion time, BC4 mode 4 5 ODTH8 ODT Assertion time, BL8 mode 6 7 Timing Parameters In synchronous ODT mode, the following parameters apply: • DODTLon, DODTLoff, RODTLoff, RODTLon4, RODTLon8, and tADC (MIN)/(MAX). • tADC (MIN) and tADC (MAX) are minimum and maximum RTT change timing skew between different termination values. These timing parameters apply to both the synchronous ODT mode and the data termination disable mode. When ODT is asserted, it must remain HIGH until minimum ODTH4 (BC = 4) or ODTH8 (BL = 8) is satisfied. If write CRC mode or 2tCK preamble mode is enabled, ODTH should be adjusted to account for it. ODTHx is measured from ODT first registered HIGH to ODT first registered LOW or from the registration of a WRITE command. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 245 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Synchronous ODT Mode Figure 193: Synchronous ODT Timing with BL8 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7  diff_CK Command ODT DODTLon = WL - 2 DODTLoff = WL - 2 t ADC DRAM_RTT tADC (MAX) tADC tADC (MIN) RTT(Park) RTT(NOM) (MAX) (MIN) RTT(Park) Transitioning Notes: 1. Example for CWL = 9, AL = 0, PL = 0; DODTLon = AL + PL + CWL - 2 = 7; DODTLoff = AL + PL + CWL - 2 = 7. 2. ODT must be held HIGH for at least ODTH8 after assertion (T1). Figure 194: Synchronous ODT with BC4 T0 T1 T2 T3 T4 T5 T18 T19 T20 T21 T22 T23 T36 T37 T38 T39 T40 T41 42 diff_CK WRS4 Command ODTH4 ODT DODTLoff = WL - 2 ODTLcnw= WL - 2 ODTLcwn4 = ODTLcnw + 4 DODTLon = CWL - 2 tADC (MAX) tADC RTT(Park) (MIN) tADC (MAX) tADC (MIN) RTT(NOM) RTT(Park) tADC (MAX) tADC (MIN) RTT(WR) tADC tADC (MAX) (MIN) RTT(Park) DRAM_RTT Transitioning Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Example for CWL = 9, AL = 10, PL = 0; DODTLon/off = AL + PL+ CWL - 2 = 17; ODTcnw = AL + PL+ CWL - 2 = 17. 2. ODT must be held HIGH for at least ODTH4 after assertion (T1). 246 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Synchronous ODT Mode ODT During Reads Because the DRAM cannot terminate with RTT and drive with RON at the same time, RTT may nominally not be enabled until the end of the postamble as shown in the example below. At cycle T25 the device turns on the termination when it stops driving, which is determined by tHZ. If the DRAM stops driving early (that is, tHZ is early), then tADC (MIN) timing may apply. If the DRAM stops driving late (that is, tHZ is late), then the DRAM complies with tADC (MAX) timing. Using CL = 11 as an example for the figure below: PL = 0, AL = CL - 1 = 10, RL = PL + AL + CL = 21, CWL= 9; RODTLoff = RL - 2 = 19, DODTLon = PL + AL + CWL - 2 = 17, 1tCK preamble. Figure 195: ODT During Reads 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 GLIIB&. &RPPDQG $GGUHVV 5' $ 5/ $/&/3/ 2'7 52'7/RII 5/ '2'7/RQ :/ W $'&0$; W $'&0$; W $'&0,1 '46B2'7 W &.3UHDPEOH W $'&0,1 577120 5773DUN W $'&0$; W $'&0$; W $'&0,1 '46B2'7 W &.3UHDPEOH W $'&0,1 577120 5773DUN '46GLII W $'&0$;Q&. W $'&0,1 '4B2'7 W &.3UHDPEOH 577120 5773DUN '4 4$ 4$ 4$ 4$ 4$ 4$ 4$ 4$ W $'&0$;Q&. W $'&0,1 '4B2'7 W &.3UHDPEOH W $'&0$; W $'&0,1 W $'&0$; W $'&0,1 577120 5773DUN '4 4$ 4$ 4$ 4$ 4$ 4$ 4$ 4$ 7UDQVLWLRQLQJ PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 247 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Dynamic ODT Dynamic ODT In certain application cases and to further enhance signal integrity on the data bus, it is desirable that the termination strength of the device can be changed without issuing an MRS command. This requirement is supported by the dynamic ODT feature. Functional Description Dynamic ODT mode is enabled if bit A9 or A10 of MR2 is set to 1. • Three RTT values are available: RTT(NOM), RTT(WR), and RTT(Park). – The value for RTT(NOM) is preselected via bits MR1[10:8]. – The value for RTT(WR) is preselected via bits MR2[11:9]. – The value for RTT(Park) is preselected via bits MR5[8:6]. • During operation without WRITE commands, the termination is controlled as follows: – Nominal termination strength RTT(NOM) or RTT(Park) is selected. – RTT(NOM) on/off timing is controlled via ODT pin and latencies DODTLon and DODTLoff, and RTT(Park) is on when ODT is LOW. • When a WRITE command (WR, WRA, WRS4, WRS8, WRAS4, and WRAS8) is registered, and if dynamic ODT is enabled, the termination is controlled as follows: – Latency ODTLcnw after the WRITE command, termination strength R TT(WR) is selected. – Latency ODTLcwn8 (for BL8, fixed by MRS or selected OTF) or ODTLcwn4 (for BC4, fixed by MRS or selected OTF) after the WRITE command, termination strength RTT(WR) is de-selected. One or two clocks will be added into or subtracted from ODTLcwn8 and ODTLcwn4, depending on write CRC mode and/or 2tCK preamble enablement. The following table shows latencies and timing parameters relevant to the on-die termination control in dynamic ODT mode. The dynamic ODT feature is not supported in DLL-off mode. An MRS command must be used to set RTT(WR) to disable dynamic ODT externally (MR2[11:9] = 000). Table 70: Dynamic ODT Latencies and Timing (1tCK Preamble Mode and CRC Disabled) Name and Description Abbr. Defined from Defined to Definition for All DDR4 Speed Bins Unit ODTLcnw = WL - 2 tCK ODT latency for change from RTT(Park)/RTT(NOM) to RTT(WR) ODTLcnw Registering external Change RTT strength WRITE command from RTT(Park)/RTT(NOM) to RTT(WR) ODT latency for change from RTT(WR) to RTT(Park)/RTT(NOM) (BC = 4) ODTLcwn 4 Registering external WRITE command Change RTT strength from RTT(WR) to RTT(Park)/RTT(NOM) ODTLcwn4 = 4 + ODTLcnw tCK ODT latency for change from RTT(WR) to RTT(Park)/RTT(NOM) (BL = 8) ODTLcwn 8 Registering external WRITE command Change RTT strength from RTT(NOM) to RTT(WR) ODTLcwn8 = 6 + ODTLcnw tCK (AVG) tADC ODTLcnw ODTLcwn RTT valid RTT change skew PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 248 tADC tADC (MIN) = 0.3 (MAX) = 0.7 tCK (AVG) Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Dynamic ODT Table 71: Dynamic ODT Latencies and Timing with Preamble Mode and CRC Mode Matrix 1tCK Parameter 2tCK Parameter Symbol CRC Off CRC On CRC Off CRC On Unit ODTLcnw1 WL - 2 WL - 2 WL - 3 WL - 3 tCK ODTLcwn4 ODTLcnw + 4 ODTLcnw + 7 ODTLcnw + 5 ODTLcnw + 8 ODTLcwn8 ODTLcnw + 6 ODTLcnw + 7 ODTLcnw + 7 ODTLcnw + 8 1. ODTLcnw = WL - 2 (1tCK preamble) or WL - 3 (2tCK preamble). Note: Figure 196: Dynamic ODT (1t CK Preamble; CL = 14, CWL = 11, BL = 8, AL = 0, CRC Disabled) T0 T1 T2 T5 T6 T7 T8 T9 T10 T11 T14 T15 T16 T17 T18 T19 T20 T21 T22 T23 T24 diff_CK Command WR ODT DODTLon = WL - 2 DODTLoff = WL - 2 tADC RTT tADC (MAX) RTT(Park) tADC (MAX) RTT(WR) tADC RTT(NOM) RTT(Park) tADC (MIN) (MIN) tADC tADC (MAX) (MIN) (MAX) RTT(Park) tADC (MIN) ODTLcnw ODTLcwn Transitioning Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. ODTLcnw = WL - 2 (1tCK preamble) or WL - 3 (2tCK preamble). 2. If BC4, then ODTLcwn = WL + 4 if CRC disabled or WL + 5 if CRC enabled; If BL8, then ODTLcwn = WL + 6 if CRC disabled or WL + 7 if CRC enabled. 249 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Dynamic ODT Figure 197: Dynamic ODT Overlapped with RTT(NOM) (CL = 14, CWL = 11, BL = 8, AL = 0, CRC Disabled) T0 T1 T2 T5 T6 T7 T9 T10 T11 T12 T15 T16 T17 T18 T19 T20 T21 T22 T23 T24 T25 diff_CK Command WR ODT ODTLcnw ODTLcwn8 tADC RTT tADC (MAX) RTT_NOM tADC (MAX) RTT_WR tADC RTT_NOM tADC (MIN) (MIN) (MAX) RTT_PARK tADC (MIN) DODTLoff = CWL -2 Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Behavior with WR command issued while ODT is registered HIGH. 250 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Asynchronous ODT Mode Asynchronous ODT Mode Asynchronous ODT mode is selected when the DRAM runs in DLL-off mode. In asynchronous ODT timing mode, the internal ODT command is not delayed by either additive latency (AL) or the parity latency (PL) relative to the external ODT signal (RTT(NOM)). In asynchronous ODT mode, two timing parameters apply: tAONAS (MIN/MAX), and tAOFAS (MIN/MAX). RTT(NOM) Turn-on Time • Minimum RTT(NOM) turn-on time (tAONAS [MIN]) is when the device termination circuit leaves RTT(Park) and ODT resistance begins to turn on. • Maximum RTT(NOM) turn-on time (tAONAS [MAX]) is when the ODT resistance has reached RTT(NOM). • tAONAS (MIN) and tAONAS (MAX) are measured from ODT being sampled HIGH. RTT(NOM) Turn-off Time • Minimum RTT(NOM) turn-off time (tAOFAS [MIN]) is when the device's termination circuit starts to leave RTT(NOM). • Maximum RTT(NOM) turn-off time (tAOFAS [MAX]) is when the on-die termination has reached RTT(Park). • tAOFAS (MIN) and tAOFAS (MAX) are measured from ODT being sampled LOW. Figure 198: Asynchronous ODT Timings with DLL Off T0 T1 T2 T3 T4 T5 T6 Ti Ti + 1 Ti + 2 Ti + 3 Ti + 4 Ti + 5 Ti + 6 Ta Tb diff_CK CKE tIH tIS tIH tIS ODT tAONAS RTT (MAX) tAONAS RTT(Park) (MIN) RTT(NOM) tAONAS (MIN) tAONAS (MAX) Transitioning PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 251 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Specifications Electrical Specifications Absolute Ratings Stresses greater than those listed may cause permanent damage to the device. This is a stress rating only, and functional operation of the device at these or any other conditions outside those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may adversely affect reliability. Although "unlimited" row accesses to the same row is allowed within the refresh period; excessive row accesses to the same row over a long term can result in degraded operation. Table 72: Absolute Maximum Ratings Symbol Parameter Min Max Unit Notes V 1 VDD Voltage on VDD pin relative to VSS –0.4 1.5 VDDQ Voltage on VDDQ pin relative to VSS –0.4 1.5 V 1 VPP Voltage on VPP pin relative to VSS –0.4 3.0 V 3 VIN, VOUT Voltage on any pin relative to VSS –0.4 1.5 V Storage temperature –55 150 °C TSTG 2 1. VDD and VDDQ must be within 300mV of each other at all times, and VREF must not be greater than 0.6 × VDDQ. When VDD and VDDQ are 85 95 °C 2 1. The normal temperature range specifies the temperatures at which all DRAM specifications will be supported. During operation, the DRAM case temperature must be maintained between 0°C to 85°C under all operating conditions for the commercial offering; The industrial temperature offering allows the case temperature to go below 0°C to -40°C. 2. Some applications require operation of the commercial and industrial temperature DRAMs in the extended temperature range (between 85°C and 95°C case temperature). Full specifications are supported in this range, but the following additional conditions apply: • REFRESH commands must be doubled in frequency, reducing the refresh interval tREFI to 3.9μs. It is also possible to specify a component with 1X refresh (tREFI to 7.8μs) in the extended temperature range. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 252 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Operating Conditions • If SELF REFRESH operation is required in the extended temperature range, it is mandatory to use either the manual self refresh mode with extended temperature range capability (MR2[6] = 0 and MR2 [7] = 1) or enable the optional auto self refresh mode (MR2 [6] = 1 and MR2 [7] = 1). Electrical Characteristics – AC and DC Operating Conditions Supply Operating Conditions Table 74: Recommended Supply Operating Conditions Rating Symbol Parameter Min Typ Max Unit Notes VDD Supply voltage 1.14 1.2 1.26 V 1, 2, 3, 4, 5 VDDQ Supply voltage for output 1.14 1.2 1.26 V 1, 2, 6 Wordline supply voltage 2.375 2.5 2.750 V 7 VPP Notes: 1. Under all conditions VDDQ must be less than or equal to VDD. 2. VDDQ tracks with VDD. AC parameters are measured with VDD and VDDQ tied together. 3. VDD slew rate between 300mV and 80% of VDD,min shall be between 0.004 V/ms and 600 V/ms, 20 MHz band-limited measurement. 4. VDD ramp time from 300mV to VDD,min shall be no longer than 200ms. 5. A stable valid VDD level is a set DC level (0 Hz to 250 KHz) and must be no less than VDD,min and no greater than VDD,max. If the set DC level is altered anytime after initialization, the DLL reset and calibrations must be performed again after the new set DC level is final. AC noise of ±60mV (greater than 250 KHz) is allowed on VDD provided the noise doesn't alter VDD to less than VDD,min or greater than VDD,max. 6. A stable valid VDDQ level is a set DC level (0 Hz to 250 KHz) and must be no less than VDDQ,min and no greater than VDDQ,max. If the set DC level is altered anytime after initialization, the DLL reset and calibrations must be performed again after the new set DC level is final. AC noise of ±60mV (greater than 250 KHz) is allowed on VDDQ provided the noise doesn't alter VDDQ to less than VDDQ,min or greater than VDDQ,max. 7. A stable valid VPP level is a set DC level (0 Hz to 250 KHz) and must be no less than VPP,min and no greater than VPP,max. If the set DC level is altered anytime after initialization, the DLL reset and calibrations must be performed again after the new set DC level is final. AC noise of ±120mV (greater than 250 KHz) is allowed on VPP provided the noise doesn't alter VPP to less than VPP,min or greater than VPP,max. Table 75: VDD Slew Rate Symbol Min Max Unit Notes VDD_sl 0.004 600 V/ms 1, 2 VDD_on – 200 ms 3 Notes: 1. Measurement made between 300mV and 80% VDD (minimum level). 2. The DC bandwidth is limited to 20 MHz. 3. Maximum time to ramp VDD from 300 mV to VDD minimum. Leakages PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 253 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Operating Conditions Table 76: Leakages Condition Symbol Min Max Unit Notes Input leakage (excluding ZQ and TEN) IIN –2 2 μA 1 ZQ leakage IZQ –3 3 μA 1 TEN leakage ITEN –6 10 μA 1, 2 VREFCA leakage IVREFCA –2 2 μA 3 Output leakage: VOUT = VDDQ IOZpd – 5 μA 4 Output leakage: VOUT = VSSQ IOZpu –50 – μA 4, 5 Notes: 1. 2. 3. 4. 5. Input under test 0V < VIN < 1.1V. Additional leakage due to weak pull-down. VREFCA = VDD/2, VDD at valid level after initialization. DQs are disabled. ODT is disabled with the ODT input HIGH. VREFCA Supply VREFCA is to be supplied to the DRAM and equal to V DD/2. The V REFCA is a reference supply input and therefore does not draw biasing current. The DC-tolerance limits and AC-noise limits for the reference voltages V REFCA are illustrated in the figure below. The figure shows a valid reference voltage V REF(t) as a function of time (VREF stands for V REFCA). V REF(DC) is the linear average of V REF(t) over a very long period of time (1 second). This average has to meet the MIN/MAX requirements. Furthermore, V REF(t) may temporarily deviate from V REF(DC) by no more than ±1% V DD for the AC-noise limit. Figure 199: VREFDQ Voltage Range Voltage VDD VREF(t) VREF AC-noise VREF(DC) MAX VREF(DC) VDD/2 VREF(DC) MIN VSS Time PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 254 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Operating Conditions The voltage levels for setup and hold time measurements are dependent on V REF. V REF is understood as V REF(DC), as defined in the above figure. This clarifies that DC-variations of V REF affect the absolute voltage a signal has to reach to achieve a valid HIGH or LOW level, and therefore, the time to which setup and hold is measured. System timing and voltage budgets need to account for V REF(DC) deviations from the optimum position within the data-eye of the input signals. This also clarifies that the DRAM setup/hold specification and derating values need to include time and voltage associated with V REF AC-noise. Timing and voltage effects due to AC-noise on V REF up to the specified limit (±1% of V DD) are included in DRAM timings and their associated deratings. VREFDQ Supply and Calibration Ranges The device internally generates its own V REFDQ. DRAM internal V REFDQ specification parameters: voltage range, step size, V REF step time, V REF full step time, and V REF valid level are used to help provide estimated values for the internal V REFDQ and are not pass/fail limits. The voltage operating range specifies the minimum required range for DDR4 SDRAM devices. The minimum range is defined by V REFDQ,min and V REFDQ,max. A calibration sequence should be performed by the DRAM controller to adjust V REFDQ and optimize the timing and voltage margin of the DRAM data input receivers. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 255 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Operating Conditions Table 77: VREFDQ Specification Parameter Symbol Min Typ Max Unit Notes Range 1 VREFDQ operating points VREFDQ R1 60% – 92% VDDQ 1, 2 Range 2 VREFDQ operating points VREFDQ R2 45% – 77% VDDQ 1, 2 VREF,step 0.5% 0.65% 0.8% VDDQ 3 VREF,set_tol –1.625% 0% 1.625% VDDQ 4, 5, 6 –0.15% 0% 0.15% VDDQ 4, 7, 8 VREF step size VREF set tolerance VREF step time VREF valid tolerance Notes: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. VREF,time – – 150 ns 9, 10, 11 VREF_val_tol –0.15% 0% 0.15% VDDQ 12 VREF(DC) voltage is referenced to VDDQ(DC). VDDQ(DC) is 1.2V. DRAM range 1 or range 2 is set by the MRS6[6]6. VREF step size increment/decrement range. VREF at DC level. VREF,new = VREF,old ±n × VREF,step; n = number of steps. If increment, use “+,” if decrement, use “-.” For n >4, the minimum value of VREF setting tolerance = VREF,new - 1.625% × VDDQ. The maximum value of VREF setting tolerance = VREF,new + 1.625% × VDDQ. Measured by recording the MIN and MAX values of the VREF output over the range, drawing a straight line between those points, and comparing all other VREF output settings to that line. For n ≤4, the minimum value of VREF setting tolerance = VREF,new - 0.15% × VDDQ. The maximum value of VREF setting tolerance = VREF,new + 0.15% × VDDQ. Measured by recording the MIN and MAX values of the VREF output across four consecutive steps (n = 4), drawing a straight line between those points, and comparing all VREF output settings to that line. Time from MRS command to increment or decrement one step size for VREF. Time from MRS command to increment or decrement more than one step size up to the full range of VREF. If the VREF monitor is enabled, VREF must be derated by +10ns if DQ bus load is 0pF and an additional +15 ns/pF of DQ bus loading. Only applicable for DRAM component-level test/characterization purposes. Not applicable for normal mode of operation. VREF valid qualifies the step times, which will be characterized at the component level. VREFDQ Ranges MR6[6] selects range 1 (60% to 92.5% of V DDQ) or range 2 (45% to 77.5% of V DDQ), and MR6[5:0] sets the V REFDQ level, as listed in the following table. The values in MR6[6:0] will update the V DDQ range and level independent of MR6[7] setting. It is recommended MR6[7] be enabled when changing the settings in MR6[6:0], and it is highly recommended MR6[7] be enabled when changing the settings in MR6[6:0] multiple times during a calibration routine. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 256 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels Table 78: VREFDQ Range and Levels MR6[5:0] MR6[6] 0 = Range 1 MR6[6] 1 = Range 2 MR6[5:0] MR6[6] 0 = Range 1 MR6[6] 1 = Range 2 00 0000 60.00% 45.00% 01 1010 76.90% 61.90% 00 0001 60.65% 45.65% 01 1011 77.55% 62.55% 00 0010 61.30% 46.30% 01 1100 78.20% 63.20% 00 0011 61.95% 46.95% 01 1101 78.85% 63.85% 00 0100 62.60% 47.60% 01 1110 79.50% 64.50% 00 0101 63.25% 48.25% 01 1111 80.15% 65.15% 00 0110 63.90% 48.90% 10 0000 80.80% 65.80% 00 0111 64.55% 49.55% 10 0001 81.45% 66.45% 00 1000 65.20% 50.20% 10 0010 82.10% 67.10% 00 1001 65.85% 50.85% 10 0011 82.75% 67.75% 00 1010 66.50% 51.50% 10 0100 83.40% 68.40% 00 1011 67.15% 52.15% 10 0101 84.05% 69.05% 00 1100 67.80% 52.80% 10 0110 84.70% 69.70% 00 1101 68.45% 53.45% 10 0111 85.35% 70.35% 00 1110 69.10% 54.10% 10 1000 86.00% 71.00% 00 1111 69.75% 54.75% 10 1001 86.65% 71.65% 01 0000 70.40% 55.40% 10 1010 87.30% 72.30% 01 0001 71.05% 56.05% 10 1011 87.95% 72.95% 01 0010 71.70% 56.70% 10 1100 88.60% 73.60% 01 0011 72.35% 57.35% 10 1101 89.25% 74.25% 01 0100 73.00% 58.00% 10 1110 89.90% 74.90% 01 0101 73.65% 58.65% 10 1111 90.55% 75.55% 01 0110 74.30% 59.30% 11 0000 91.20% 76.20% 01 0111 74.95% 59.95% 11 0001 91.85% 76.85% 01 1000 75.60% 60.60% 11 0010 92.50% 77.50% 01 1001 76.25% 61.25% 11 0011 to 11 1111 are reserved Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels RESET_n Input Levels Table 79: RESET_n Input Levels (CMOS) Parameter Symbol Min Max Unit Note AC input high voltage VIH(AC)_RESET 0.8 × VDD VDD V 1 DC input high voltage VIH(DC)_RESET 0.7 × VDD VDD V 2 DC input low voltage VIL(DC)_RESET VSS 0.3 × VDD V 3 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 257 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels Table 79: RESET_n Input Levels (CMOS) (Continued) Parameter Symbol Min Max Unit Note VIL(AC)_RESET VSS 0.2 × VDD V 4 tR_RESET – 1 μs 5 RESET pulse width after power-up tPW_RESET_S 1 – μs 6, 7 RESET pulse width during power-up tPW_RESET_L 200 – μs 6 AC input low voltage Rising time Notes: 1. Overshoot should not exceed the VIN shown in the Absolute Maximum Ratings table. 2. After RESET_n is registered HIGH, the RESET_n level must be maintained above VIH(DC)_RESET, otherwise operation will be uncertain until it is reset by asserting RESET_n signal LOW. 3. After RESET_n is registered LOW, the RESET_n level must be maintained below VIL(DC)_REt SET during PW_RESET, otherwise the DRAM may not be reset. 4. Undershoot should not exceed the VIN shown in the Absolute Maximum Ratings table. 5. Slope reversal (ring-back) during this level transition from LOW to HIGH should be mitigated as much as possible. 6. RESET is destructive to data contents. 7. See RESET Procedure at Power Stable Condition figure. Figure 200: RESET_n Input Slew Rate Definition tPW_RESET VIH(AC)_RESET,min VIH(DC)_RESET,min VIL(DC)_RESET,max VIL(AC)_RESET,max tR_RESET Command/Address Input Levels Table 80: Command and Address Input Levels: DDR4-1600 Through DDR4-2400 Parameter Symbol Min Max Unit Note AC input high voltage VIH(AC) VREF + 100 VDD5 mV 1, 2, 3 DC input high voltage VIH(DC) VREF + 75 VDD mV 1, 2 DC input low voltage VIL(DC) VSS VREF - 75 mV 1, 2 AC input low voltage Reference voltage for CMD/ADDR inputs Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. 2. 3. 4. VIL(AC) VSS5 VREF - 100 mV 1, 2, 3 VREFFCA(DC) 0.49 × VDD 0.51 × VDD V 4 For input except RESET_n. VREF = VREFCA(DC). VREF = VREFCA(DC). Input signal must meet VIL/VIH(AC) to meet tIS timings and VIL/VIH(DC) to meet tIH timings. The AC peak noise on VREF may not allow VREF to deviate from VREFCA(DC) by more than ±1% VDD (for reference: approximately ±12mV). 258 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels 5. Refer to “Overshoot and Undershoot Specifications.” Table 81: Command and Address Input Levels: DDR4-2666 Parameter Symbol Min Max Unit Note AC input high voltage VIH(AC) VREF + 90 VDD5 mV 1, 2, 3 DC input high voltage VIH(DC) VREF + 65 VDD mV 1, 2 DC input low voltage VIL(DC) VSS VREF - 65 mV 1, 2 AC input low voltage VIL(AC) VSS5 VREF - 90 mV 1, 2, 3 VREFFCA(DC) 0.49 × VDD 0.49 × VDD V 4 Reference voltage for CMD/ADDR inputs Notes: 1. 2. 3. 4. For input except RESET_n. VREF = VREFCA(DC). VREF = VREFCA(DC). Input signal must meet VIL/VIH(AC) to meet tIS timings and VIL/VIH(DC) to meet tIH timings. The AC peak noise on VREF may not allow VREF to deviate from VREFCA(DC) by more than ±1% VDD (for reference: approximately ±12mV). 5. Refer to “Overshoot and Undershoot Specifications.” Table 82: Command and Address Input Levels: DDR4-2933 and DDR4-3200 Parameter Symbol Min Max Unit Note AC input high voltage VIH(AC) VREF + 90 VDD5 mV 1, 2, 3 DC input high voltage VIH(DC) VREF + 65 VDD mV 1, 2 DC input low voltage VIL(DC) VSS VREF - 65 mV 1, 2 AC input low voltage VIL(AC) VSS5 VREF - 90 mV 1, 2, 3 VREFFCA(DC) 0.49 × VDD 0.49 × VDD V 4 Reference voltage for CMD/ADDR inputs Notes: 1. 2. 3. 4. For input except RESET_n. VREF = VREFCA(DC). VREF = VREFCA(DC). Input signal must meet VIL/VIH(AC) to meet tIS timings and VIL/VIH(DC) to meet tIH timings. The AC peak noise on VREF may not allow VREF to deviate from VREFCA(DC) by more than ±1% VDD (for reference: approximately ±12mV). 5. Refer to “Overshoot and Undershoot Specifications.” Table 83: Single-Ended Input Slew Rates Parameter Single-ended input slew rate – CA Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. 2. 3. 4. Symbol Min Max Unit Note SRCA 1.0 7.0 V/ns 1, 2, 3, 4 For input except RESET_n. VREF = VREFCA(DC). tIS/tIH timings assume SR CA = 1V/ns. Measured between VIH(AC) and VIL(AC) for falling edges and between VIL(AC) and VIH(AC) for rising edges 259 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels Figure 201: Single-Ended Input Slew Rate Definition TRse TFse VIH(AC) VIH(DC) VREFCA VIL(DC) VIL(AC) PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 260 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels Data Receiver Input Requirements The following parameters apply to the data receiver Rx MASK operation detailed in the Write Timing section, Data Strobe-to-Data Relationship. The rising edge slew rates are defined by srr1 and srr2. The slew rate measurement points for a rising edge are shown in the figure below. A LOW-to-HIGH transition time, tr1, is measured from 0.5 × V diVW,max below V CENTDQ,midpoint to the last transition through 0.5 × V diVW,max above V CENTDQ,midpoint; tr2 is measured from the last transition through 0.5 × V diVW,max above V CENTDQ,midpoint to the first transition through the 0.5 × VIHL(AC)min above V CENTDQ,midpoint. The falling edge slew rates are defined by srf1 and srf2. The slew rate measurement points for a rising edge are shown in the figure below. A HIGH-to-LOW transition time, tf1, is measured from 0.5 × V diVW,max above V CENTDQ,midpoint to the last transition through 0.5 × V diVW,max below V CENTDQ,midpoint; tf2 is measured from the last transition through 0.5 × V diVW,max below V CENTDQ,midpoint to the first transition through the 0.5 × VIHL(AC)min below V CENTDQ,midpoint. Figure 202: DQ Slew Rate Definitions 0.5 × VdiVW,max VCENTDQ,midpoint 0.5 × VdiVW,max VdiVW,max 0.5 × VIHL(AC)min tr1 tf1 Rx Mask 0.5 × VdiVW,max VCENTDQ,midpoint 0.5 × VdiVW,max VdiVW,max 0.5 × VIHL(AC)min 0.5 × VIHL(AC)min Rx Mask 0.5 × VIHL(AC)min VIHL(AC)min VIHL(AC)min tr2 tf2 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Rising edge slew rate equation srr1 = VdiVW,max/(tr1). 2. Rising edge slew rate equation srr2 = (VIHL(AC)min - VdiVW,max )/(2 × tr2). 3. Falling edge slew rate equation srf1 = VdiVW,max/(tf1). 261 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels 4. Falling edge slew rate equation srf2 = (VIHL(AC)min - VdiVW,max )/(2 × tf2). Table 84: DQ Input Receiver Specifications Note 1 applies to the entire table DDR4-1600, 1866, 2133 Parameter DDR4-2400 DDR4-2666 DDR4-2933 DDR4-3200 Symbol Min Max Min Max Min Max Min Max Min Max Unit Not es VIN Rx mask input peak-to-peak VdiVW – 136 – 130 – 120 – 115 – 110 mV 2, 3 DQ Rx input timing window TdiVW – 0.2 – 0.2 – 0.22 – 0.23 – 0.23 UI 2, 3 DQ AC input swing peak-topeak VIHL(AC) 186 – 160 – 150 – 145 – 140 – mV 4, 5 DQ input pulse width TdiPW 0.58 – 0.58 – 0.58 – 0.58 – 0.58 – UI 6 DQS-to-DQ Rx mask offset tDQS2D –0.17 0.17 –0.17 0.17 –0.19 0.19 –0.22 0.22 –0.22 0.22 UI 7 DQ-to-DQ Rx mask offset tDQ2DQ – 0.1 – 0.1 – 0.105 – 0.115 – 0.125 UI 8 srr1, srf1 Input slew rate over VdiVW if tCK ≥ 0.925ns 1 9 1 9 1 9 1 9 1 9 V/ns 9 Input slew rate over VdiVW if 0.935ns > tCK ≥ 0.625ns srr1, srf1 – – 1.25 9 1.25 9 1.25 9 1.25 9 V/ns 9 Rising input slew rate over 1/2 VIHL(AC) srr2 0.2 × srr1 9 0.2 × srr1 9 0.2 × srr1 9 0.2 × srr1 9 0.2 × srr1 9 V/ns 10 Falling input slew rate over 1/2 VIHL(AC) srf2 0.2 × srf1 9 0.2 × srf1 9 0.2 × srf1 9 0.2 × srf1 9 0.2 × srf1 9 V/ns 10 Q Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. All Rx mask specifications must be satisfied for each UI. For example, if the minimum input pulse width is violated when satisfying TdiVW (MIN), VdiVW,max, and minimum slew rate limits, then either TdiVW (MIN) or minimum slew rates would have to be increased to the point where the minimum input pulse width would no longer be violated. 2. Data Rx mask voltage and timing total input valid window where VdiVW is centered around VCENTDQ,midpoint after VREFDQ training is completed. The data Rx mask is applied per bit and should include voltage and temperature drift terms. The input buffer design specification is to achieve at least a BER =1e- 16 when the Rx mask is not violated. 3. Defined over the DQ internal VREF range 1. 4. Overshoot and undershoot specifications apply. 5. DQ input pulse signal swing into the receiver must meet or exceed VIHL(AC)min. VIHL(AC)min is to be achieved on an UI basis when a rising and falling edge occur in the same UI (a valid TdiPW). 6. DQ minimum input pulse width defined at the VCENTDQ,midpoint. 262 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels 7. DQS-to-DQ Rx mask offset is skew between DQS and DQ within a nibble (x4) or word (x8, x16 [for x16, the upper and lower bytes are treated as separate x8s]) at the SDRAM balls over process, voltage, and temperature. 8. DQ-to-DQ Rx mask offset is skew between DQs within a nibble (x4) or word (x8, x16) at the SDRAM balls for a given component over process, voltage, and temperature. 9. Input slew rate over VdiVW mask centered at VCENTDQ,midpoint. Slowest DQ slew rate to fastest DQ slew rate per transition edge must be within 1.7V/ns of each other. 10. Input slew rate between VdiVW mask edge and VIHL(AC)min points. The following figure shows the Rx mask relationship to the input timing specifications relative to system tDS and tDH. The classical definition for tDS/tDH required a DQ rising and falling edges to not violate tDS and tDH relative to the DQS strobe at any time; however, with the Rx mask tDS and tDH can shift relative to the DQS strobe provided the input pulse width specification is satisfied and the Rx mask is not violated. Figure 203: Rx Mask Relative to tDS/tDH TdiPW VIH(DC) VdiVW 0.5 × VdiVW VCENTDQ,pin mean Rx Mask 0.5 × VdiVW VIL(DC) tf1 tr1 TdiVW tDS tDH = Greater of 0.5 × TdiVW or 0.5 × (TdiPW + VdiVW/tf1) = Greater of 0.5 × TdiVW or 0.5 × (TdiPW + VdiVW/tr1) DQS_c DQS_t The following figure and table show an example of the worst case Rx mask required if the DQS and DQ pins do not have DRAM controller to DRAM write DQ training. The figure and table show that without DRAM write DQ training, the Rx mask would increase from 0.2UI to essentially 0.54UI. This would also be the minimum tDS and tDH required as well. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 263 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels Figure 204: Rx Mask Without Write Training TdiVW + 2 × tDQS2DQ VdiVW VIH(DC) 0.5 × VdiVW Rx Mask VCENTDQ,midpoint 0.5 × VdiVW VIL(DC) tDS tDH 0.5 × TdiVW + tDQS2DQ 0.5 × TdiVW + tDQS2DQ DQS_c DQS_t Table 85: Rx Mask andtDS/tDH Without Write Training DDR4 VIHL(AC) (mV) TdiPW (UI) VdiVW (mV) TdiVW (UI) tDQS2DQ tDQ2DQ (UI) 1600 186 0.58 136 0.2 1866 186 0.58 136 2133 186 0.58 136 2400 160 0.58 2666 150 2933 3200 tDS/tDH_No (UI) Rx Mask (ps) Training (ps) ±0.17 0.1 125 338 0.2 ±0.17 0.1 107.1 289 0.2 ±0.17 0.1 3.84 253 130 0.2 ±0.17 0.1 83.3 225 0.58 120 0.22 ±0.19 0.105 82.5 225 145 0.58 115 0.23 ±0.22 0.115 78.4 228 140 0.58 110 0.23 ±0.22 0.125 71.8 209 Note: 1. VIHL(AC), VdiVW, and VILH(DC) referenced to VCENTDQ,midpoint. Connectivity Test (CT) Mode Input Levels Table 86: TEN Input Levels (CMOS) Parameter Symbol Min Max Unit Note TEN AC input high voltage VIH(AC)_TEN 0.8 × VDD VDD V 1 TEN DC input high voltage VIH(DC)_TEN 0.7 × VDD VDD V TEN DC input low voltage VIL(DC)_TEN VSS 0.3 × VDD V TEN AC input low voltage VIL(AC)_TEN VSS 0.2 × VDD V tF_TEN – 10 ns TEN falling time PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 264 2 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels Table 86: TEN Input Levels (CMOS) (Continued) Parameter TEN rising time Symbol Min Max Unit tR_TEN – 10 ns Note 1. Overshoot should not exceed the VIN values in the Absolute Maximum Ratings table. 2. Undershoot should not exceed the VIN values in the Absolute Maximum Ratings table. Notes: Figure 205: TEN Input Slew Rate Definition VIH(AC)_TENmin VIH(DC)_TENmin VIL(DC)_TENmin VIL(AC)_TENmin tF_TEN tR_TEN Table 87: CT Type-A Input Levels Parameter Symbol Min Max Unit Note CTipA AC input high voltage VIH(AC) VREF + 200 VDD11 V 2, 3 CTipA DC input high voltage VIH(DC) VREF + 150 VDD V 2, 3 CTipA DC input low voltage VIL(DC) VSS VREF - 150 V 2, 3 1 VIL(AC) VSS1 VREF - 200 V 2, 3 CTipA falling time tF_CTipA – 5 ns 2 CTipA rising time tR_CTipA – 5 ns 2 CTipA AC input low voltage Notes: 1. Refer to Overshoot and Undershoot Specifications. 2. CT Type-A inputs: CS_n, BG[1:0], BA[1:0], A[9:0], A10/AP, A11, A12/BC_n, A13, WE_n/A14, CAS_n/A15, RAS_n/A16, CKE, ACT_n, ODT, CLK_t, CLK_C, PAR. 3. VREFCA = 0.5 × VDD. Figure 206: CT Type-A Input Slew Rate Definition VIH(AC)_CTipAmin VIH(DC)_CTipAmin VREFCA VIL(DC)_CTipAmax VIL(AC)_CTipAmax tR_CTipA tF_CTipA PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 265 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels Table 88: CT Type-B Input Levels Parameter Symbol Min Max Unit Note CTipB AC input high voltage VIH(AC) VREF + 300 VDD11 V 2, 3 CTipB DC input high voltage VIH(DC) VREF + 200 VDD V 2, 3 CTipB DC input low voltage VIL(DC) VSS VREF - 200 V 2, 3 1 VIL(AC) VSS1 VREF - 300 V 2, 3 CTipB falling time tF_CTipB – 5 ns 2 CTipB rising time tR_CTipB – 5 ns 2 CTipB AC input low voltage Notes: 1. Refer to Overshoot and Undershoot Specifications. 2. CT Type-B inputs: DML_n/DBIL_n, DMU_n/DBIU_n and DM_n/DBI_n. 3. VREFDQ should be 0.5 × VDD Figure 207: CT Type-B Input Slew Rate Definition VIH(AC)_CTipBmin VIH(DC)_CTipBmin VREFDQ VIL(DC)_CTipBmax VIL(AC)_CTipBmax tF_CTipB tR_CTipB Table 89: CT Type-C Input Levels (CMOS) Parameter Symbol Min Max Unit Note 1 V 2 CTipC AC input high voltage VIH(AC)_CTipC 0.8 × VDD VDD CTipC DC input high voltage VIH(DC)_CTipC 0.7 × VDD VDD V 2 CTipC DC input low voltage VIL(DC)_CTipC VSS 0.3 × VDD V 2 CTipC AC input low voltage VIL(AC)_CTipC VSS1 0.2 × VDD V 2 CTipC falling time tF_CTipC – 10 ns 2 CTipC rising time tR_CTipC – 10 ns 2 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Refer to Overshoot and Undershoot Specifications. 2. CT Type-C inputs: Alert_n. 266 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Single-Ended Input Measurement Levels Figure 208: CT Type-C Input Slew Rate Definition VIH(AC)_TENmin VIH(DC)_TENmin VIL(DC)_TENmin VIL(AC)_TENmin tF_TEN tR_TEN Table 90: CT Type-D Input Levels Parameter Symbol Min Max Unit Note CTipD AC input high voltage VIH(AC)_CTipD 0.8 × VDD VDD V 4 CTipD DC input high voltage VIH(DC)_CTipD 0.7 × VDD VDD V 2 CTipD DC input low voltage VIL(DC)_CTipD VSS 0.3 × VDD V 1 CTipD AC input low voltage VIL(AC)_CTipD VSS 0.2 × VDD V 5 tR_RESET – 1 μs 3 RESET pulse width - after power-up tPW_RESET_S 1 – μs RESET pulse width - during power-up tPW_RESET_L 200 – μs Rising time Notes: 1. After RESET_n is registered LOW, the RESET_n level must be maintained below VIL(DC)_REt SET during PW_RESET, otherwise, the DRAM may not be reset. 2. After RESET_n is registered HIGH, the RESET_n level must be maintained above VIH(DC)_RESET, otherwise, operation will be uncertain until it is reset by asserting RESET_n signal LOW. 3. Slope reversal (ring-back) during this level transition from LOW to HIGH should be mitigated as much as possible. 4. Overshoot should not exceed the VIN values in the Absolute Maximum Ratings table. 5. Undershoot should not exceed the VIN values in the Absolute Maximum Ratings table. 6. CT Type-D inputs: RESET_n; same requirements as in normal mode. Figure 209: CT Type-D Input Slew Rate Definition tPW_RESET VIH(AC)_RESETmin VIH(DC)_RESETmin VIL(DC)_RESETmax VIL(AC)_RESETmax tR_RESET PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 267 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Differential Input Measurement Levels Electrical Characteristics – AC and DC Differential Input Measurement Levels Differential Inputs Figure 210: Differential AC Swing and “Time Exceeding AC-Level” tDVAC tDVAC VIH,diff(AC)min VIH,diff,min CK_t, CK_c 0.0 VIL,diff,max VIL,diff(AC)max tDVAC Half cycle Notes: 1. Differential signal rising edge from VIL,diff,max to VIH,diff(AC)min must be monotonic slope. 2. Differential signal falling edge from IH,diff,min to VIL,diff(AC)max must be monotonic slope. Table 91: Differential Input Swing Requirements for CK_t, CK_c DDR4-1600 / 1866 / 2133 / 2400 Parameter DDR4-2666 / 2933 / 3200 Symbol Min Max Min Max Unit Notes Differential input high VIHdiff 0.150 Note 3 0.120 Note 3 V 1 Differential input low VILdiff Note 3 –0.150 Note 3 -0.120 V 1 Differential input high (AC) VIHdiff(AC) 2 × (VIH(AC) - VREF) Note 3 2 × (VIH(AC) - VREF) Note 3 V 2 Differential input low (AC) VILdiff(AC) Note 3 2 × (VIL(AC) VREF) Note 3 2 × (VIL(AC) VREF) V 2 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Used to define a differential signal slew-rate. 2. For CK_t, CK_c use VIH(AC) and VIL(AC) of ADD/CMD and VREFCA. 268 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Differential Input Measurement Levels 3. These values are not defined; however, the differential signals (CK_t, CK_c) need to be within the respective limits, VIH(DC)max and VIL(DC)min for single-ended signals as well as the limitations for overshoot and undershoot. Table 92: Minimum Time AC Time tDVAC for CK tDVAC Note: (ps) at |VIH,diff(AC) to VIL,diff(AC)| Slew Rate (V/ns) 200mV TBDmV >4.0 120 TBD 4.0 115 TBD 3.0 110 TBD 2.0 105 TBD 1.9 100 TBD 1.6 95 TBD 1.4 90 TBD 1.2 85 TBD 1.0 80 TBD VDD/2 + 145mV N/A 120mV N/A 120mV VDD/2 + 100mV ≤ VSEH ≤ VDD/2 + 145mV N/A (VSEH - VDD/2) 25mV N/A (VSEH - VDD/2) 25mV VDD/2 - 145mV ≤ VSEL ≤ VDD/2 100mV –(VDD/2-VSEL) +25mV N/A –(VDD/2-VSEL) + 25mV N/A VSEL ≤ VDD/2 - 145mV –120mV N/A –120mV N/A Table 96: Cross Point Voltage For CK Differential Input Signals at DDR4-2666 through DDR4-3200 DDR4-2666 DDR4-2933, 3200 Parameter Sym Input Level Min Max Min Max Differential input cross point voltage relative to VDD/2 for CK_t, CK_c VIX(CK) VSEH > VDD/2 + 135mV N/A 110mV N/A 110mV VDD/2 + 90mV ≤ VSEH ≤ VDD/2 + 135mV N/A (VSEH - VDD/2) 30mV N/A (VSEH - VDD/2) 30mV N/A –(VDD/2-VSEL) + 30mV N/A N/A –110mV N/A VDD/2 - 135mV ≤ VSEL ≤ VDD/2 - –(VDD/2-VSEL) + 90mV 30mV VSEL ≤ VDD/2 - 135mV –110mV DQS Differential Input Signal Definition and Swing Requirements DQS_t, DQS_c: Differential Input Voltage Figure 214: Differential Input Signal Definition for DQS_t, DQS_c PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN VIH,diff,peak Half cycle 0.0V Half cycle VIL,diff,peak 272 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Differential Input Measurement Levels Table 97: DDR4-1600 through DDR4-2400 Differential Input Swing Requirements for DQS_t, DQS_c DDR4-1600, 1866, 2133 Parameter DDR4-2400 Symbol Min Max Min Max Unit Notes Peak differential input high voltage VIH,diff,peak 186 VDDQ 160 VDDQ mV 1,2 Peak differential input low voltage VIL,diff,peak VSSQ –186 VSSQ –160 mV 1,2 1. Minimum and maximum limits are relative to single-ended portion and can be exceeded within allowed overshoot and undershoot limits. 2. Minimum value point is used to determine differential signal slew-rate. Notes: Table 98: DDR4-2633 through DDR4-3200 Differential Input Swing Requirements for DQS_t, DQS_c DDR4-2666 DDR4-2933 DDR4-3200 Symbol Min Max Min Max Min Max Unit Notes Peak differential input high voltage VIH,diff,peak 150 VDDQ 145 VDDQ 140 VDDQ mV 1,2 Peak differential input low voltage VIL,diff,peak VSSQ –150 VSSQ –145 VSSQ –140 mV 1,2 Parameter 1. Minimum and maximum limits are relative to single-ended portion and can be exceeded within allowed overshoot and undershoot limits. 2. Minimum value point is used to determine differential signal slew-rate. Notes: The peak voltage of the DQS signals are calculated using the following equations: VIH,dif,Peak voltage = MAX(ft) VIL,dif,Peak voltage = MIN(ft) (ft) = DQS_t, DQS_c. The MAX(f(t)) or MIN(f(t)) used to determine the midpoint from which to reference the ±35% window of the exempt non-monotonic signaling shall be the smallest peak voltage observed in all UIs. DQS_t, DQS_c: Single-Ended Input Voltages Figure 215: DQS_t, DQS_c Input Peak Voltage Calculation and Range of Exempt non-Monotonic Signaling PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN DQS_t +35% +50% MIN(ft) MAX(ft) –35% –50% DQS_c 273 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Differential Input Measurement Levels DQS Differential Input Cross Point Voltage To achieve tight RxMask input requirements as well as output skew parameters with respect to strobe, the cross point voltage of differential input signals (DQS_t, DQS_c) must meet V IX_DQS,ratio in the table below. The differential input cross point voltage V IX_DQS (VIX_DQS_FR and V IX_DQS_RF) is measured from the actual cross point of DQS_t, DQS_c relative to the V DQS,mid of the DQS_t and DQS_c signals. VDQS,mid is the midpoint of the minimum levels achieved by the transitioning DQS_t and DQS_c signals, and noted by V DQS_trans. V DQS_trans is the difference between the lowest horizontal tangent above V DQS,mid of the transitioning DQS signals and the highest horizontal tangent below V DQS,mid of the transitioning DQS signals. A non-monotonic transitioning signal’s ledge is exempt or not used in determination of a horizontal tangent provided the said ledge occurs within ±35% of the midpoint of either V IH.DIFF.Peak voltage (DQS_t rising) or V IL.DIFF.Peak voltage (DQS_c rising), as shown in the figure below. A secondary horizontal tangent resulting from a ring-back transition is also exempt in determination of a horizontal tangent. That is, a falling transition’s horizontal tangent is derived from its negative slope to zero slope transition (point A in the figure below), and a ring-back’s horizontal tangent is derived from its positive slope to zero slope transition (point B in the figure below) and is not a valid horizontal tangent; a rising transition’s horizontal tangent is derived from its positive slope to zero slope transition (point C in the figure below), and a ring-back’s horizontal tangent derived from its negative slope to zero slope transition (point D in the figure below) and is not a valid horizontal tangent. Figure 216: VIXDQS Definition Lowest horizontal tanget above VDQS,mid of the transitioning signals VIX_DQS,RF VIX_DQS,FR VDQS,mid VIX_DQS,FR VIX_DQS,RF B VDQS_trans D VDQS_trans/2 DQS_t, DQS_c: Single-Ended Input Voltages C DQS_t DQS_c A Highest horizontal tanget below VDQS,mid of the transitioning signals VSSQ Table 99: Cross Point Voltage For Differential Input Signals DQS DDR4-1600, 1866, 2133, 2400, 2666, 2933, 3200 Parameter DQS_t and DQS_c crossing relative to the midpoint of the DQS_t and DQS_c signal swings PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Symbol Min Max Unit Notes VIX_DQS,ratio – 25 % 1, 2 274 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Differential Input Measurement Levels Table 99: Cross Point Voltage For Differential Input Signals DQS (Continued) DDR4-1600, 1866, 2133, 2400, 2666, 2933, 3200 Parameter VDQS,mid to Vcent(midpoint) offset Symbol Min Max Unit Notes VDQS,mid_to_Vcent – Note 3 mV 2 1. VIX_DQS,ratio is DQS VIX crossing (VIX_DQS,FR or VIX_DQS,RF) divided by VDQS_trans. VDQS_trans is the difference between the lowest horizontal tangent above VDQS,midd of the transitioning DQS signals and the highest horizontal tangent below VDQS,mid of the transitioning DQS signals. 2. VDQS,mid will be similar to the VREFDQ internal setting value (Vcent(midpoint) offset) obtained during VREF Training if the DQS and DQs drivers and paths are matched. 3. The maximum limit shall not exceed the smaller of VIH,diff,DQS minimum limit or 50mV. Notes: Slew Rate Definitions for DQS Differential Input Signals Table 100: DQS Differential Input Slew Rate Definition Measured From To Defined by Differential input slew rate for rising edge Description V IL,diff,DQS V IH,diff,DQS |VIH,diff,DQS - VIL,diff,DQSΔTRdiff Differential input slew rate for falling edge V IH,diff,DQS V IL,diff,DQS |VIHdiffDQS - VIL,diff,DQSΔTFdiff 1. The differential signal DQS_t, DQS_c must be monotonic between these thresholds. Note: DQS_t, DQS_c: Differential Input Voltage Figure 217: Differential Input Slew Rate and Input Level Definition for DQS_t, DQS_c VIH,diff,peak VIH,diff,DQS 0.0V VIL,diff,DQS TRdiff TFdiff VIL,diff,peak Table 101: DDR4-1600 through DDR4-2400 Differential Input Slew Rate and Input Levels for DQS_t, DQS_c DDR4-1600, 1866, 2133 Parameter DDR4-2400 Symbol Min Max Min Max Unit Notes Peak differential input high voltage VIH,diff,peak 186 VDDQ 160 VDDQ mV 1 Differential input high voltage VIH,diff,DQS 136 – 130 – mV 2, 3 Differential input low voltage VIL,diff,DQS – –136 – –130 mV 2, 3 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 275 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Differential Input Measurement Levels Table 101: DDR4-1600 through DDR4-2400 Differential Input Slew Rate and Input Levels for DQS_t, DQS_c (Continued) DDR4-1600, 1866, 2133 Parameter Peak differential input low voltage DQS differential input slew rate Notes: DDR4-2400 Symbol Min Max Min Max Unit Notes VIL,diff,peak VSSQ –186 VSSQ –160 mV 1 SRIdiff 3.0 18 3.0 18 V/ns 4, 5 1. Minimum and maximum limits are relative to single-ended portion and can be exceeded within allowed overshoot and undershoot limits. 2. Differential signal rising edge from VIL,diff,DQS to VIH,diff,DQS must be monotonic slope. 3. Differential signal falling edge from VIH,diff,DQS to VIL,diff,DQS must be monotonic slope. 4. Differential input slew rate for rising edge from VIL,diff,DQS to VIH,diff,DQS is defined by | VIL,diff,min - VIH,diff,maxΔTRdiff. 5. Differential input slew rate for falling edge from VIH,diff,DQS to VIL,diff,DQS is defined by | VIL,diff,min - VIH,diff,maxΔTFdiff. Table 102: DDR4-2666 through DDR4-3200 Differential Input Slew Rate and Input Levels for DQS_t, DQS_c DDR4-2666 Parameter DDR4-2933 DDR4-3200 Symbol Min Max Min Max Min Max Unit Notes Peak differential input high voltage VIH,diff,peak 150 VDDQ 145 VDDQ 140 VDDQ mV 1 Differential input high voltage VIH,diff,DQS 120 – 115 – 110 – mV 2, 3 Differential input low voltage VIL,diff,DQS – –120 – –115 – –110 mV 2, 3 Peak differential input low voltage VIL,diff,peak VSSQ –150 VSSQ –145 VSSQ –140 mV 1 DQS differential input slew rate SRIdiff 3.0 18 3.0 18 3.0 18 V/ns 4, 5 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Minimum and maximum limits are relative to single-ended portion and can be exceeded within allowed overshoot and undershoot limits. 2. Differential signal rising edge from VIL,diff,DQS to VIH,diff,DQS must be monotonic slope. 3. Differential signal falling edge from VIH,diff,DQS to VIL,diff,DQS must be monotonic slope. 4. Differential input slew rate for rising edge from VIL,diff,DQS to VIH,diff,DQS is defined by | VIL,diff,min - VIH,diff,maxΔTRdiff. 5. Differential input slew rate for falling edge from VIH,diff,DQS to VIL,diff,DQS is defined by | VIL,diff,min - VIH,diff,maxΔTFdiff. 276 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – Overshoot and Undershoot Specifications Electrical Characteristics – Overshoot and Undershoot Specifications Address, Command, and Control Overshoot and Undershoot Specifications Table 103: ADDR, CMD, CNTL Overshoot and Undershoot/Specifications DDR41600 Description DDR41866 DDR42133 DDR42400 DDR42666 DDR43200 Unit Address and control pins (A[17:0], BG[1:0], BA[1:0], CS_n, RAS_n, CAS_n, WE_n, CKE, ODT, C2-0) Area A: Maximum peak amplitude above VDD absolute MAX 0.06 0.06 0.06 0.06 TBD TBD V Area B: Amplitude allowed between VDD and VDD absolute MAX 0.24 0.24 0.24 0.24 TBD TBD V Area C: Maximum peak amplitude allowed for undershoot below VSS 0.30 0.30 0.30 0.30 TBD TBD V Area A maximum overshoot area per 1tCK 0.0083 0.0071 0.0062 0.0055 TBD TBD V/ns 1tCK 0.2550 0.2185 0.1914 0.1699 TBD TBD V/ns 0.2644 0.2265 0.1984 0.1762 TBD TBD V/ns Area B maximum overshoot area per Area C maximum undershoot area per 1tCK Figure 218: ADDR, CMD, CNTL Overshoot and Undershoot Definition Absolute MAX overshoot Volts (V) VDD absolute MAX VDD A Overshoot area above VDD absolute MAX B Overshoot area below VDD absolute MAX and above VDD MAX 1tCK VSS C PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 277 Undershoot area below VSS Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – Overshoot and Undershoot Specifications Clock Overshoot and Undershoot Specifications Table 104: CK Overshoot and Undershoot/ Specifications DDR41600 DDR41866 DDR42133 DDR42400 DDR42666 DDR43200 Unit Area A: Maximum peak amplitude above VDD absolute MAX 0.06 0.06 0.06 0.06 TBD TBD V Area B: Amplitude allowed between VDD and VDD absolute MAX 0.24 0.24 0.24 0.24 TBD TBD V Area C: Maximum peak amplitude allowed for undershoot below VSS 0.30 0.30 0.30 0.30 TBD TBD V Area A maximum overshoot area per 1UI 0.0038 0.0032 0.0028 0.0025 TBD TBD V/ns Area B maximum overshoot area per 1UI 0.1125 0.0964 0.0844 0.0750 TBD TBD V/ns Area C maximum undershoot area per 1UI 0.1144 0.0980 0.0858 0.0762 TBD TBD V/ns Description CK_t, CK_c Figure 219: CK Overshoot and Undershoot Definition Absolute MAX overshoot Volts (V) VDD absolute MAX A Overshoot area above VDD absolute MAX B Overshoot area below VDD absolute MAX and above VDD MAX VDD 1UI VSS C PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 278 Undershoot area below VSS Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Output Measurement Levels Data, Strobe, and Mask Overshoot and Undershoot Specifications Table 105: Data, Strobe, and Mask Overshoot and Undershoot/ Specifications DDR41600 DDR41866 DDR42133 DDR42400 DDR42666 DDR43200 Unit Area A: Maximum peak amplitude above VDDQ absolute MAX 0.16 0.16 0.16 0.16 TBD TBD V Area B: Amplitude allowed between VDDQ and VDDQ absolute MAX 0.24 0.24 0.24 0.24 TBD TBD V Area C: Maximum peak amplitude allowed for undershoot below VSSQ 0.30 0.30 0.30 0.30 TBD TBD V Area D: Maximum peak amplitude below VSSQ absolute MIN 0.10 0.10 0.10 0.10 TBD TBD V Area A maximum overshoot area per 1UI 0.0150 0.0129 0.0113 0.0100 TBD TBD V/ns Area B maximum overshoot area per 1UI 0.1050 0.0900 0.0788 0.0700 TBD TBD V/ns Area C maximum undershoot area per 1UI 0.1050 0.0900 0.0788 0.0700 TBD TBD V/ns Area D maximum undershoot area per 1UI 0.0150 0.0129 0.0113 0.0100 TBD TBD V/ns Description Data, Strobe, and Mask Figure 220: Data, Strobe, and Mask Overshoot and Undershoot Definition Absolute MAX overshoot Volts (V) VDDQ absolute MAX A Overshoot area above VDDQ absolute MAX B Overshoot area below VDDQ absolute MAX and above VDDQ MAX VDDQ 1UI VSSQ C VSSQ absolute MIN Undershoot area below VSSQ MIN and above VSSQ absolute MIN D Undershoot area below VSSQ absolute MIN Absolute MAX undershoot Electrical Characteristics – AC and DC Output Measurement Levels Single-Ended Outputs Table 106: Single-Ended Output Levels Parameter Symbol DDR4-1600 to DDR4-3200 Unit DC output high measurement level (for IV curve linearity) VOH(DC) 1.1 × VDDQ V DC output mid measurement level (for IV curve linearity) VOM(DC) 0.8 × VDDQ V DC output low measurement level (for IV curve linearity) VOL(DC) 0.5 × VDDQ V AC output high measurement level (for output slew rate) VOH(AC) (0.7 + 0.15) × VDDQ V PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 279 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Output Measurement Levels Table 106: Single-Ended Output Levels (Continued) Parameter AC output low measurement level (for output slew rate) Symbol DDR4-1600 to DDR4-3200 Unit VOL(AC) (0.7 - 0.15) × VDDQ V 1. The swing of ±0.15 × VDDQ is based on approximately 50% of the static single-ended output peak-to-peak swing with a driver impedance of RZQ/7 and an effective test load of 50Ω to VTT = VDDQ. Note: Using the same reference load used for timing measurements, output slew rate for falling and rising edges is defined and measured between V OL(AC) and V OH(AC) for singleended signals. Table 107: Single-Ended Output Slew Rate Definition Measured Description From To Defined by Single-ended output slew rate for rising edge VOL(AC) VOH(AC) [VOH(AC) - VOL(AC)ΔTRse Single-ended output slew rate for falling edge VOH(AC) VOL(AC) [VOH(AC) - VOL(AC)ΔTFse Figure 221: Single-ended Output Slew Rate Definition TRse Single-Ended Output Voltage (DQ) VOH(AC) VOL(AC) TFse PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 280 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Output Measurement Levels Table 108: Single-Ended Output Slew Rate For RON = RZQ/7 DDR4-1333 / 1866 / 2133 / 2400 Parameter DDR4-2666 DDR4-2933 / 3200 Symbol Min Max Min Max Min Max Unit SRQse 4 9 4 9 4 9 V/ns Single-ended output slew rate 1. SR = slew rate; Q = query output; se = single-ended signals 2. In two cases a maximum slew rate of 12V/ns applies for a single DQ signal within a byte lane: Notes: • Case 1 is defined for a single DQ signal within a byte lane that is switching into a certain direction (either from HIGH-to-LOW or LOW-to-HIGH) while all remaining DQ signals in the same byte lane are static (they stay at either HIGH or LOW). • Case 2 is defined for a single DQ signal within a byte lane that is switching into a certain direction (either from HIGH-to-LOW or LOW-to-HIGH) while all remaining DQ signals in the same byte lane are switching into the opposite direction (from LOW-toHIGH or HIGH-to-LOW, respectively). For the remaining DQ signal switching into the opposite direction, the standard maximum limit of 9 V/ns applies. Differential Outputs Table 109: Differential Output Levels Parameter Symbol DDR4-1600 to DDR4-3200 Unit AC differential output high measurement level (for output slew rate) VOH,diff(AC) 0.3 × VDDQ V AC differential output low measurement level (for output slew rate) VOL,diff(AC) –0.3 × VDDQ V Note: 1. The swing of ±0.3 × VDDQ is based on approximately 50% of the static single-ended output peak-to-peak swing with a driver impedance of RZQ/7 and an effective test load of 50Ω to VTT = VDDQ at each differential output. Using the same reference load used for timing measurements, output slew rate for falling and rising edges is defined and measured between V OL,diff(AC) and V OH,diff(AC) for differential signals. Table 110: Differential Output Slew Rate Definition Measured Description From To Defined by Differential output slew rate for rising edge VOL,diff(AC) VOH,diff(AC) [VOH,diff(AC) - VOL,diff(AC)ΔTRdiff Differential output slew rate for falling edge VOH,diff(AC) VOL,diff(AC) [VOH,diff(AC) - VOL,diff(AC)ΔTFdiff PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 281 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Output Measurement Levels Figure 222: Differential Output Slew Rate Definition Differential Input Voltage (DQS_t, DQS_c) TRdiff VOH,diff(AC) VOL,diff(AC) TFdiff Table 111: Differential Output Slew Rate For RON = RZQ/7 DDR4-1333 / 1866 / 2133 / 2400 Parameter Differential output slew rate Note: DDR4-2666 DDR4-2933 / 3200 Symbol Min Max Min Max Min Max Unit SRQdiff 8 18 8 18 8 18 V/ns 1. SR = slew rate; Q = query output; diff = differential signals. Reference Load for AC Timing and Output Slew Rate The effective reference load of 50Ω to V TT = V DDQ and driver impedance of RZQ/7 for each output was used in defining the relevant AC timing parameters of the device as well as output slew rate measurements. Ron nominal of DQ, DQS_t and DQS_c drivers uses 34 ohms to specify the relevant AC timing paraeter values of the device. The maximum DC High level of Output signal = 1.0 * VDDQ, the minimum DC Low level of Output signal = { 34 /( 34 + 50 ) } *VDDQ = 0.4* VDDQ The nominal reference level of an Output signal can be approximated by the following: The center of maximum DC High and minimum DC Low = { ( 1 + 0.4 ) / 2 } * VDDQ = 0.7 * VDDQ. The actual reference level of Output signal might vary with driver Ron and reference load tolerances. Thus, the actual reference level or midpoint of an output signal is at the widest part of the output signal’s eye. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 282 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Output Measurement Levels Figure 223: Reference Load For AC Timing and Output Slew Rate VDDQ VTT = VDDQ DQ, DQS_t, DQS_c, DM, TDQS_t, TDQS_c CK_t, CK_c DUT RTT = 50ȍ VSSQ Timing reference point Connectivity Test Mode Output Levels Table 112: Connectivity Test Mode Output Levels Parameter Symbol DDR4-1600 to DDR4-3200 Unit DC output high measurement level (for IV curve linearity) VOH(DC) 1.1 × VDDQ V DC output mid measurement level (for IV curve linearity) VOM(DC) 0.8 × VDDQ V DC output low measurement level (for IV curve linearity) VOL(DC) 0.5 × VDDQ V DC output below measurement level (for IV curve linearity) VOB(DC) 0.2 × VDDQ V AC output high measurement level (for output slew rate) VOH(AC) VTT + (0.1 × VDDQ) V AC output low measurement level (for output slew rate) VOL(AC) VTT - (0.1 × VDDQ) V Note: 1. Driver impedance of RZQ/7 and an effective test load of 50Ω to VTT = VDDQ. Figure 224: Connectivity Test Mode Reference Test Load VDDQ DQ, DQS_t, DQS_c, DM, TDQS_t, TDQS_c CT_Inputs DUT RTT = 50ȍ 0.5 × VDDQ VSSQ Timing reference point PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 283 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Output Measurement Levels Figure 225: Connectivity Test Mode Output Slew Rate Definition VOH(AC) VTT 0.5 x VDD VOL(AC) TFoutput_CT TRoutput_CT Table 113: Connectivity Test Mode Output Slew Rate DDR4-1333 / 1866 / 2133 / 2400 Parameter DDR4-2666 DDR4-2933 / 3200 Symbol Min Max Min Max Min Max Unit Output signal falling time TF_output_CT – 10 – 10 – 10 ns/V Output signal rising time TR_output_CT – 10 – 10 – 10 ns/V PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 284 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Output Driver Characteristics Electrical Characteristics – AC and DC Output Driver Characteristics Output Driver Electrical Characteristics The DDR4 driver supports two RON values. These R ON values are referred to as strong mode (low RONΩ) and weak mode (high RONΩ). A functional representation of the output buffer is shown in the figure below. Figure 226: Output Driver: Definition of Voltages and Currents Chip in drive mode Output driver VDDQ IPU To other circuitry like RCV, ... RONPU DQ IOUT RONPD VOUT IPD VSSQ The output driver impedance, RON, is determined by the value of the external reference resistor RZQ as follows: RON(34) = RZQ/7, or RON(48) = RZQ/5. This provides either a nominal 34.3Ω ±10% or 48Ω ±10% with nominal RZQ Ω The individual pull-up and pull-down resistors (RONPu and RONPd) are defined as follows: RONPu when RONPd is off: RONPU = VDDQ - VOUT IOUT RONPD when RONPU is off: RONPD = PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN VOUT IOUT 285 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Output Driver Characteristics Table 114: Strong Mode (34Ω Ω) Output Driver Electrical Characteristics Assumes RZQ Ω; Entire operating temperature range after proper ZQ calibration RON,nom Resistor VOUT Min Nim Max Unit Notes VOL(DC) = 0.5 × VDDQ 0.8 1.0 1.1 RZQ/7 1, 2, 3 VOM(DC) = 0.8 × VDDQ 0.9 1.0 1.1 RZQ/7 1, 2, 3 VOH(DC) = 1.1 × VDDQ 0.9 1.0 1.25 RZQ/7 1, 2, 3 VOL(DC) = 0.5 × VDDQ 0.9 1.0 1.25 RZQ/7 1, 2, 3 VOM(DC) = 0.8 × VDDQ 0.9 1.0 1.1 RZQ/7 1, 2, 3 VOH(DC) = 1.1 × VDDQ 0.8 1.0 1.1 RZQ/7 1, 2, 3 Mismatch between DQ to DQ within byte variation pull-up, MMPUdd VOM(DC) = 0.8 × VDDQ –10 – 10 % 1, 2, 3, 4, 5 Mismatch between DQ to DQ within byte variation pull-down, MMPDdd VOM(DC) = 0.8 × VDDQ – – 10 % 1, 2, 3, 4, 6, 7 Mismatch between pull-up and pull-down, MMPUPD VOM(DC) = 0.8 × VDDQ – – 10 % 1, 2, 3, 4, 6, 7 RON34PD Ω RON34PU Notes: 1. The tolerance limits are specified after calibration with stable voltage and temperature. For the behavior of the tolerance limits if temperature or voltage changes after calibration, see following section on voltage and temperature sensitivity. 2. The tolerance limits are specified under the condition that VDDQ = VDD and that VSSQ = VSS. 3. Micron recommends calibrating pull-down and pull-up output driver impedances at 0.8 × VDDQ. Other calibration schemes may be used to achieve the linearity specification shown above; for example, calibration at 0.5 × VDDQ and 1.1 VDDQ. 4. DQ-to-DQ mismatch within byte variation for a given component including DQS_t and DQS_c (characterized). 5. Measurement definition for mismatch between pull-up and pull-down, MMPUPD: Measure both RONPU and RONPD at 0.8 × VDDQ separately; RON,nom is the nominal RON value: MMPUPD = RONPU - RONPD × 100 RON,nom 6. RON variance range ratio to RON nominal value in a given component, including DQS_t and DQS_c: MMPUDD = MMPDDD = RONPU,max - RONPU,min RON,nom RONPD,max - RONPD,min RON,nom × 100 × 100 7. The lower and upper bytes of a x16 are each treated on a per byte basis. 8. For IT and AT devices, the minimum values are derated by 9% when the device operates between –40°C and 0°C (TC). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 286 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Output Driver Characteristics Table 115: Weak Mode (48Ω Ω) Output Driver Electrical Characteristics Assumes RZQ Ω; Entire operating temperature range after proper ZQ calibration RON,nom Resistor VOUT Min Nim Ω Max Unit Notes VOL(DC) = 0.5 × VDDQ 0.8 1.0 1.1 RZQ/5 1, 2, 3 VOM(DC) = 0.8 × VDDQ 0.9 1.0 1.1 RZQ/5 1, 2, 3 VOH(DC) = 1.1 × VDDQ 0.9 1.0 1.25 RZQ/5 1, 2, 3 VOL(DC) = 0.5 × VDDQ 0.9 1.0 1.25 RZQ/5 1, 2, 3 VOM(DC) = 0.8 × VDDQ 0.9 1.0 1.1 RZQ/5 1, 2, 3 VOH(DC) = 1.1 × VDDQ 0.8 1.0 1.1 RZQ/5 1, 2, 3 Mismatch between DQ to DQ within byte variation pull-up, MMPUdd VOM(DC) = 0.8 × VDDQ -10 – 10 % 1, 2, 3, 4, 5 Mismatch between DQ to DQ within byte variation pull-down, MMPDdd VOM(DC) = 0.8 × VDDQ – – 10 % 1, 2, 3, 4, 6, 7 Mismatch between pull-up and pull-down, MMPUPD VOM(DC) = 0.8 × VDDQ – – 10 % 1, 2, 3, 4, 6, 7 RON34PD RON34PU Notes: 1. The tolerance limits are specified after calibration with stable voltage and temperature. For the behavior of the tolerance limits if temperature or voltage changes after calibration, see following section on voltage and temperature sensitivity. 2. The tolerance limits are specified under the condition that VDDQ = VDD and that VSSQ = VSS. 3. Micron recommends calibrating pull-down and pull-up output driver impedances at 0.8 × VDDQ. Other calibration schemes may be used to achieve the linearity specification shown above; for example, calibration at 0.5 × VDDQ and 1.1 VDDQ. 4. DQ-to-DQ mismatch within byte variation for a given component including DQS_t and DQS_c (characterized). 5. Measurement definition for mismatch between pull-up and pull-down, MMPUPD: Measure both RONPU and RONPD at 0.8 × VDDQ separately; RON,nom is the nominal RON value: MMPUPD = RONPU - RONPD × 100 RON,nom 6. RON variance range ratio to RON nominal value in a given component, including DQS_t and DQS_c: MMPUDD = MMPDDD = RONPU,max - RONPU,min RON,nom RONPD,max - RONPD,min RON,nom × 100 × 100 7. The lower and upper bytes of a x16 are each treated on a per byte basis. 8. For IT and AT devices, the minimum values are derated by 9% when the device operates between –40°C and 0°C (TC). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 287 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – AC and DC Output Driver Characteristics Output Driver Temperature and Voltage Sensitivity If temperature and/or voltage change after calibration, the tolerance limits widen according to the equations and tables below. ΔT = T - T(@calibration); ΔV = V DDQ - V DDQ(@ calibration); V DD = V DDQ Table 116: Output Driver Sensitivity Definitions Symbol Min Max Unit RONPU@ VOH(DC) 0.6 - dRONdTH × |ΔT| - dRONdVH × |ΔV| 1.1 _ dRONdTH × |ΔT| + dRONdVH × |ΔV| RZQ/6 RON@ VOM(DC) 0.9 - dRONdTM × |ΔT| - dRONdVM × |ΔV| 1.1 + dRONdTM × |ΔT| + dRONdVM × |ΔV| RZQ/6 RONPD@ VOL(DC) 0.6 - dRONdTL × |ΔT| - dRONdVL × |ΔV| 1.1 + dRONdTL × |ΔT| + dRONdVL × |ΔV| RZQ/6 Table 117: Output Driver Voltage and Temperature Sensitivity Voltage and Temperature Range Symbol Min Max Unit dRONdTM 0 1.5 %/°C dRONdVM 0 0.15 %/mV dRONdTL 0 1.5 %/°C dRONdVL 0 0.15 %/mV dRONdTH 0 1.5 %/°C dRONdVM 0 0.15 %/mV Alert Driver A functional representation of the alert output buffer is shown in the figure below. Output driver impedance, RON, is defined as follows. Figure 227: Alert Driver Alert driver '5$0 Alert RONPD IOUT IPD VOUT VSSQ RONPD when RONPU is off: RONPD = PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN VOUT IOUT 288 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – On-Die Termination Characteristics Table 118: Alert Driver Voltage RON,nom Register VOUT Min Nom Max Unit N/A RONPD VOL(DC) = 0.1 × VDDQ 0.3 N/A 1.2 RZQ/7 VOM(DC) = 0.8 × VDDQ 0.4 N/A 1.12 RZQ/7 VOH(DC) = 1.1 × VDDQ 0.4 N/A 1.4 RZQ/7 Note: 1. VDDQ voltage is at VDDQ(DC). Electrical Characteristics – On-Die Termination Characteristics ODT Levels and I-V Characteristics On-die termination (ODT) effective resistance settings are defined and can be selected by any or all of the following options: • MR1[10:8] (RTT(NOM)): Disable, 240 ohms, 120 ohms, 80 ohms, 60 ohms, 48 ohms, 40 ohms, and 34 ohms. • MR2[11:9] (RTT(WR)): Disable, 240 ohms,120 ohms, and 80 ohms. • MR5[8:6] (RTT(Park)): Disable, 240 ohms, 120 ohms, 80 ohms, 60 ohms, 48 ohms, 40 ohms, and 34 ohms. ODT is applied to the following inputs: • x4: DQ, DM_n, DQS_t, and DQS_c inputs. • x8: DQ, DM_n, DQS_t, DQS_c, TDQS_t, and TDQS_c inputs. • x16: DQ, LDM_n, UDM_n, LDQS_t, LDQS_c, UDQS_t, and UDQS_c inputs. A functional representation of ODT is shown in the figure below. Figure 228: ODT Definition of Voltages and Currents Chip in termination mode ODT To other circuitry like RCV, ... VDDQ RTT DQ IOUT VOUT VSSQ PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 289 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – On-Die Termination Characteristics Table 119: ODT DC Characteristics RTT VOUT Min Nom Max Unit Notes 240 ohm VOL(DC) = 0.5 × VDDQ 0.9 1 1.25 RZQ 1, 2, 3 VOM(DC) = 0.8 × VDDQ 0.9 1 1.1 RZQ 1, 2, 3 VOH(DC) = 1.1 × VDDQ 0.8 1 1.1 RZQ 1, 2, 3 120 ohm 80 ohm 60 ohm 48 ohm 40 ohm 34 ohm DQ-to-DQ mismatch within byte VOL(DC) = 0.5 × VDDQ 0.9 1 1.25 RZQ/2 1, 2, 3 VOM(DC) = 0.8 × VDDQ 0.9 1 1.1 RZQ/2 1, 2, 3 VOH(DC) = 1.1 × VDDQ 0.8 1 1.1 RZQ/2 1, 2, 3 VOL(DC) = 0.5 × VDDQ 0.9 1 1.25 RZQ/3 1, 2, 3 VOM(DC) = 0.8 × VDDQ 0.9 1 1.1 RZQ/3 1, 2, 3 VOH(DC) = 1.1 × VDDQ 0.8 1 1.1 RZQ/3 1, 2, 3 VOL(DC) = 0.5 × VDDQ 0.9 1 1.25 RZQ/4 1, 2, 3 VOM(DC) = 0.8 × VDDQ 0.9 1 1.1 RZQ/4 1, 2, 3 VOH(DC) = 1.1 × VDDQ 0.8 1 1.1 RZQ/4 1, 2, 3 VOL(DC) = 0.5 × VDDQ 0.9 1 1.25 RZQ/5 1, 2, 3 VOM(DC) = 0.8 × VDDQ 0.9 1 1.1 RZQ/5 1, 2, 3 VOH(DC) = 1.1 × VDDQ 0.8 1 1.1 RZQ/5 1, 2, 3 VOL(DC) = 0.5 × VDDQ 0.9 1 1.25 RZQ/6 1, 2, 3 VOM(DC) = 0.8 × VDDQ 0.9 1 1.1 RZQ/6 1, 2, 3 VOH(DC) = 1.1 × VDDQ 0.8 1 1.1 RZQ/6 1, 2, 3 VOL(DC) = 0.5 × VDDQ 0.9 1 1.25 RZQ/7 1, 2, 3 VOM(DC) = 0.8 × VDDQ 0.9 1 1.1 RZQ/7 1, 2, 3 VOH(DC) = 1.1 × VDDQ 0.8 1 1.1 RZQ/7 1, 2, 3 VOM(DC) = 0.8 × VDDQ 0 – 10 % 1, 2, 4, 5, 6 Notes: 1. The tolerance limits are specified after calibration to 240 ohm ±1% resistor with stable voltage and temperature. For the behavior of the tolerance limits if temperature or voltage changes after calibration, see ODT Temperature and Voltage Sensitivity. 2. Micron recommends calibrating pull-up ODT resistors at 0.8 × VDDQ. Other calibration schemes may be used to achieve the linearity specification shown here. 3. The tolerance limits are specified under the condition that VDDQ = VDD and VSSQ = VSS. 4. The DQ-to-DQ mismatch within byte variation for a given component including DQS_t and DQS_c. 5. RTT variance range ratio to RTT nominal value in a given component, including DQS_t and DQS_c. DQ-to-DQ mismatch = RTT(MAX) - RTT(MIN) RTT(NOM) × 100 6. DQ-to-DQ mismatch for a x16 device is treated as two separate bytes. 7. For IT and AT devices, the minimum values are derated by 9% when the device operates between –40°C and 0°C (TC). PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 290 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – On-Die Termination Characteristics ODT Temperature and Voltage Sensitivity If temperature and/or voltage change after calibration, the tolerance limits widen according to the following equations and tables. ΔT = T - T(@ calibration); ΔV = V DDQ - V DDQ(@ calibration); V DD = V DDQ Table 120: ODT Sensitivity Definitions Parameter Min Max Unit RTT@ 0.9 - dRTTdT × |ΔT| - dRTTdV × |ΔV| 1.6 + dRTTdTH × |ΔT| + dRTTdVH × |ΔV| RZQ/n Table 121: ODT Voltage and Temperature Sensitivity Parameter Min Max Unit dRTTdT 0 1.5 %/°C dRTTdV 0 0.15 %/mV ODT Timing Definitions The reference load for ODT timings is different than the reference load used for timing measurements. Figure 229: ODT Timing Reference Load VDDQ DQ, DQS_t, DQS_c, DM, TDQS_t, TDQS_c CK_t, CK_c DUT VSSQ RTT = 50ȍ VTT = VSSQ Timing reference point ODT Timing Definitions and Waveforms Definitions for tADC, tAONAS, and tAOFAS are provided in the Table 122 (page 292) and shown in Figure 230 (page 293) and Figure 232 (page 294). Measurement reference settings are provided in the subsequent Table 123 (page 292). The tADC for the dynamic ODT case and read disable ODT cases are represented by tADC of Direct ODT Control case. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 291 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – On-Die Termination Characteristics Table 122: ODT Timing Definitions Parameter tADC Begin Point Definition End Point Definition Figure Rising edge of CK_t, CK_c defined by the end point of DODTLoff Extrapolated point at VRTT,nom Figure 230 (page 293) Rising edge of CK_t, CK_c defined by the end point of DODTLon Extrapolated point at VSSQ Figure 230 (page 293) Rising edge of CK_t, CK_c defined by the end point of ODTLcnw Extrapolated point at VRTT,nom Figure 231 (page 293) Rising edge of CK_t, CK_c defined by the end point of ODTLcwn4 or ODTLcwn8 Extrapolated point at VSSQ Figure 231 (page 293) tAONAS Rising edge of CK_t, CK_c with ODT being first registered HIGH Extrapolated point at VSSQ Figure 232 (page 294) tAOFAS Rising edge of CK_t, CK_c with ODT being first registered LOW Extrapolated point at VRTT,nom Figure 232 (page 294) Table 123: Reference Settings for ODT Timing Measurements Measure Parameter RTT(Park) RTT(NOM) RTT(WR) VSW1 VSW2 Note tADC Disable RZQΩ – 0.20V 0.40V 1, 2, 4 – RZQΩ High-Z 0.20V 0.40V 1, 3, 5 tAONAS Disable RZQΩ – 0.20V 0.40V 1, 2, 6 tAOFAS Disable RZQΩ – 0.20V 0.40V 1, 2, 6 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. MR settings are as follows: MR1 has A10 = 1, A9 = 1, A8 = 1 for RTT(NOM) setting; MR5 has A8 = 0, A7 = 0, A6 = 0 for RTT(Park) setting; and MR2 has A11 = 0, A10 = 1, A9 = 1 for RTT(WR) setting. 2. ODT state change is controlled by ODT pin. 3. ODT state change is controlled by a WRITE command. 4. Refer to Figure 230 (page 293). 5. Refer to Figure 231 (page 293). 6. Refer to Figure 232 (page 294). 292 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – On-Die Termination Characteristics Figure 230: tADC Definition with Direct ODT Control DODTLoff Begin point: Rising edge of CK_t, CK_c defined by the end point of DODTLoff DODTLon Begin point: Rising edge of CK_t, CK_c defined by the end point of DODTLon CK_c CK_t tADC VRTT,nom tADC End point: Extrapolated point at VRTT,nom VRTT,nom Vsw2 DQ, DM DQS_t, DQS_c TDQS_t, TDQS_c Vsw1 VSSQ VSSQ End point: Extrapolated point at VSSQ Figure 231: tADC Definition with Dynamic ODT Control ODTLcnw Begin point: Rising edge of CK_t, CK_c defined by the end point of ODTLcnw ODTLcnw4/8 Begin point: Rising edge of CK_t, CK_c defined by the end point of ODTLcnw4 or ODTLcnw8 CK_c CK_t tADC VRTT,nom tADC End point: Extrapolated point at VRTT,nom Vsw2 DQ, DM DQS_t, DQS_c TDQS_t, TDQS_c PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN VRTT,nom Vsw1 VSSQ 293 VSSQ End point: Extrapolated point at VSSQ Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Electrical Characteristics – On-Die Termination Characteristics Figure 232: tAOFAS and tAONAS Definitions Rising edge of CK_t, CK_c with ODT being first registered LOW Rising edge of CK_t, CK_c with ODT being first registered HIGH CK_c CK_t tAOFAS VRTT,nom tAONAS End point: Extrapolated point at VRTT_NOM Vsw2 DQ, DM DQS_t, DQS_c TDQS_t, TDQS_c PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN VRTT,nom Vsw1 VSSQ 294 VSSQ End point: Extrapolated point at VSSQ Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM DRAM Package Electrical Specifications DRAM Package Electrical Specifications Table 124: DRAM Package Electrical Specifications for x4 and x8 Devices 1600, 1866 Parameter Input/ output DQS_t, DQS_c Input CTRL pins Input CMD ADD pins CK_t, CK_c 2133, 2400 2666, 3200 Symbol Min Max Min Max Min Max Unit Notes ZIO 45 85 45 85 TBD TBD ohm 1, 2, 4 TdIO 14 42 14 42 TBD TBD ps 1, 3, 4 Lpkg LIO – 3.3 – 3.3 TBD TBD nH Cpkg CIO – 0.78 – 0.78 TBD TBD pF Zpkg Package delay ZIO DQS 45 85 45 85 TBD TBD ohm 1, 2 Package delay TdIO DQS 14 42 14 42 TBD TBD ps 1, 3 Delta Zpkg DZIO DQS – 10 – 10 TBD TBD ohm 1, 2, 6 Delta delay DTdIO DQS – 5 – 5 TBD TBD ps 1, 3, 6 Zpkg Lpkg LIO DQS – 3.3 – 3.3 TBD TBD nH Cpkg CIO DQS – 0.78 – 0.78 TBD TBD pF Zpkg ZI CTRL 50 90 50 90 TBD TBD ohm 1, 2, 8 TdI CTRL 14 42 14 42 TBD TBD ps 1, 3, 8 Package delay Lpkg LI CTRL – 3.4 – 3.4 TBD TBD nH Cpkg CI CTRL – 0.7 – 0.7 TBD TBD pF Zpkg ZI ADD CMD 50 90 50 90 TBD TBD ohm 1, 2, 7 TdI ADD CMD 14 45 14 45 TBD TBD ps 1, 3, 7 Package delay Lpkg LI ADD CMD – 3.6 – 3.6 TBD TBD nH Cpkg CI ADD CMD – 0.74 – 0.74 TBD TBD pF Zpkg ZCK 50 90 50 90 TBD TBD ohm 1, 2 TdCK 14 42 14 42 TBD TBD ps 1, 3 Delta Zpkg DZDCK – 10 – 10 TBD TBD ohm 1, 2, 5 Delta delay DTdDCK – 5 – 5 TBD TBD ps 1, 3, 5 Lpkg LI CLK – 3.4 – 3.4 TBD TBD nH Cpkg CI CLK – 0.7 – 0.7 TBD TBD pF Package delay ZQ Zpkg ZO ZQ 40 100 40 100 TBD TBD ohm 1, 2 ZQ delay TdO ZQ 20 55 20 55 TBD TBD ps 1, 3 ALERT Zpkg ZO ALERT 40 100 40 100 TBD TBD ohm 1, 2 ALERT delay TdO ALERT 20 55 20 55 TBD TBD ps 1, 3 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. The package parasitic (L and C) are validated using package only samples. The capacitance is measured with VDD, VDDQ, VSS, and VSSQ shorted with all other signal pins floating. The inductance is measured with VDD, VDDQ, VSS, and VSSQ shorted and all other signal pins shorted at the die, not pin, side. 2. Package-only impedance (Zpkg) is calculated based on the Lpkg and Cpkg total for a given pin where: Zpkg (total per pin) = SQRT (Lpkg/Cpkg). 3. Package-only delay (Tpkg) is calculated based on Lpkg and Cpkg total for a given pin where: Tdpkg (total per pin) = SQRT (Lpkg × Cpkg). 4. ZIO and TdIO apply to DQ, DM, DQS_c, DQS_t, TDQS_t, and TDQS_c. 295 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM DRAM Package Electrical Specifications 5. Absolute value of ZCK_t, ZCK_c for impedance (Z) or absolute value of TdCK_t, TdCK_c for delay (Td). 6. Absolute value of ZIO (DQS_t), ZIO (DQS_c) for impedance (Z) or absolute value of TdIO (DQS_t), TdIO (DQS_c) for delay (Td). 7. ZI ADD CMD and TdI ADD CMD apply to A[17:0], BA[1:0], BG[1:0], RAS_n CAS_n, and WE_n. 8. ZI CTRL and TdI CTRL apply to ODT, CS_n, and CKE. 9. Package implementations will meet specification if the Zpkg and package delay fall within the ranges shown, and the maximum Lpkg and Cpkg do not exceed the maximum values shown. 10. It is assumed that Lpkg can be approximated as Lpkg = ZO × Td. 11. It is assumed that Cpkg can be approximated as Cpkg = Td/ZO. Table 125: DRAM Package Electrical Specifications for x16 Devices 1600, 1866 Parameter Input/ output DQSL_t/ DQSL_c/ DQSU_t/ DQSU_c 2133, 2400 2666, 3200 Symbol Min Max Min Max Min Max Unit Notes ZIO 45 85 45 85 TBD TBD ohm 1, 2, 4 TdIO 14 45 14 45 TBD TBD ps 1, 3, 4 Lpkg LIO – 3.4 – 3.4 TBD TBD nH Cpkg CIO – 0.82 – 0.82 TBD TBD pF Zpkg ZIO DQS 45 85 45 85 TBD TBD ohm 1, 2 TdIO DQS 14 45 14 45 TBD TBD ps 1, 3 Zpkg Package delay Package delay Lpkg LIO DQS – 3.4 – 3.4 TBD TBD nH Cpkg CIO DQS – 0.82 – 0.82 TBD TBD pF DQSL_t/ DQSL_c, DQSU_t/ DQSU_c, Delta Zpkg DZIO DQS – 10 – 10 TBD TBD ohm 1, 2, 6 Delta delay DTdIO DQS – 5 – 5 TBD TBD ps 1, 3, 6 Input CTRL pins Zpkg ZI CTRL 50 90 50 90 TBD TBD ohm 1, 2, 8 1, 3, 8 Input CMD ADD pins CK_t, CK_c TdI CTRL 14 42 14 42 TBD TBD ps Lpkg LI CTRL – 3.4 – 3.4 TBD TBD nH Cpkg CI CTRL – 0.7 – 0.7 TBD TBD pF Zpkg ZI ADD CMD 50 90 50 90 TBD TBD ohm 1, 2, 7 1, 3, 7 Package delay TdI ADD CMD 14 52 14 52 TBD TBD ps Lpkg LI ADD CMD – 3.9 – 3.9 TBD TBD nH Cpkg CI ADD CMD – 0.86 – 0.86 TBD TBD pF Zpkg ZCK 50 90 50 90 TBD TBD ohm Package delay TdCK 14 42 14 42 TBD TBD ps 1, 3 Delta Zpkg DZDCK – 10 – 10 TBD TBD ohm 1, 2, 5 Delta delay DTdDCK – 5 – 5 TBD TBD ps 1, 3, 5 Lpkg LI CLK – 3.4 – 3.4 TBD TBD nH Cpkg Package delay Input CLK 1, 2 CI CLK – 0.7 – 0.7 TBD TBD pF ZQ Zpkg ZO ZQ 40 100 40 100 TBD TBD ohm 1, 2 ZQ delay TdO ZQ 20 90 20 90 TBD TBD ps 1, 3 ALERT Zpkg ZO ALERT 40 100 40 100 TBD TBD ohm 1, 2 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 296 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM DRAM Package Electrical Specifications Table 125: DRAM Package Electrical Specifications for x16 Devices (Continued) 1600, 1866 2133, 2400 2666, 3200 Parameter Symbol Min Max Min Max Min Max Unit Notes ALERT delay TdO ALERT 20 55 20 55 TBD TBD ps 1, 3 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. The package parasitic (L and C) are validated using package only samples. The capacitance is measured with VDD, VDDQ, VSS, and VSSQ shorted with all other signal pins floating. The inductance is measured with VDD, VDDQ, VSS, and VSSQ shorted and all other signal pins shorted at the die, not pin, side. 2. Package-only impedance (Zpkg) is calculated based on the Lpkg and Cpkg total for a given pin where: Zpkg (total per pin) = SQRT (Lpkg/Cpkg). 3. Package-only delay (Tpkg) is calculated based on Lpkg and Cpkg total for a given pin where: Tdpkg (total per pin) = SQRT (Lpkg × Cpkg). 4. ZIO and TdIO apply to DQ, DM, DQS_c, DQS_t, TDQS_t, and TDQS_c. 5. Absolute value of ZCK_t, ZCK_c for impedance (Z) or absolute value of TdCK_t, TdCK_c for delay (Td). 6. Absolute value of ZIO (DQS_t), ZIO (DQS_c) for impedance (Z) or absolute value of TdIO (DQS_t), TdIO (DQS_c) for delay (Td). 7. ZI ADD CMD and TdI ADD CMD apply to A[17:0], BA[1:0], BG[1:0], RAS_n CAS_n, and WE_n. 8. ZI CTRL and TdI CTRL apply to ODT, CS_n, and CKE. 9. Package implementations will meet specification if the Zpkg and package delay fall within the ranges shown, and the maximum Lpkg and Cpkg do not exceed the maximum values shown. 10. It is assumed that Lpkg can be approximated as Lpkg = ZO × Td. 11. It is assumed that Cpkg can be approximated as Cpkg = Td/ZO. 297 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM DRAM Package Electrical Specifications Table 126: Pad Input/Output Capacitance DDR4-1600, 1866, 2133 Parameter DDR4-2400, 2666 DDR4-3200 Symbol Min Max Min Max Min Max Unit Notes Input/output capacitance: DQ, DM, DQS_t, DQS_c, TDQS_t, TDQS_c CIO 0.55 1.4 0.55 1.15 0.55 1.15 pF 1, 2, 3 Input capacitance: CK_t and CK_c CCK 0.2 0.8 0.2 0.7 0.2 0.7 pF 1, 2, 3, 4 Input capacitance delta: CK_t and CK_c CDCK 0 0.05 0 0.05 0 0.05 pF 1, 2, 3, 5 Input/output capacitance delta: DQS_t and DQS_c CDDQS 0 0.05 0 0.05 0 0.05 pF 1, 3 CI 0.2 0.8 0.2 0.7 0.2 0.7 pF 1, 3, 6 Input capacitance delta: All CTRL input-only pins CDI_CTRL –0.1 0.1 –0.1 0.1 –0.1 0.1 pF 1, 3, 7 Input capacitance delta: All ADD/CMD input-only pins CDI_ADD_CMD –0.1 0.1 –0.1 0.1 –0.1 0.1 pF 1, 3, 8, 9 CDIO –0.1 0.1 –0.1 0.1 –0.1 0.1 pF 1, 2, 10, 11 CALERT 0.5 1.5 0.5 1.5 0.5 1.5 pF 1, 3 Input/output capacitance: ZQ pin CZQ 0.5 2.3 0.5 2.3 0.5 2.3 pF 1, 3, 12 Input/output capacitance: TEN pin CTEN 0.2 2.3 0.2 2.3 0.2 2.3 pF 1, 3, 13 Input capacitance: CTRL, ADD, CMD input-only pins Input/output capacitance delta: DQ, DM, DQS_t, DQS_c, TDQS_t, TDQS_c Input/output capacitance: ALERT pin Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Although the DM, TDQS_t, and TDQS_c pins have different functions, the loading matches DQ and DQS. 2. This parameter is not subject to a production test; it is verified by design and characterization. The capacitance is measured according to the JEP147 specification, “Procedure for Measuring Input Capacitance Using a Vector Network Analyzer (VNA),” with VDD, VDDQ, VSS, and VSSQ applied and all other pins floating (except the pin under test, CKE, RESET_n and ODT, as necessary). VDD = VDDQ = 1.5V, VBIAS = VDD/2 and on-die termination off. 3. This parameter applies to monolithic die, obtained by de-embedding the package L and C parasitics. 4. CDIO = CIO(DQ, DM) - 0.5 × (CIO(DQS_t) + CIO(DQS_c)). 5. Absolute value of CIO (DQS_t), CIO (DQS_c) 6. Absolute value of CCK_t, CCK_c 7. CI applies to ODT, CS_n, CKE, A[15:0], BA[1:0], RAS_n, CAS_n, and WE_n. 8. CDI_CTRL applies to ODT, CS_n, and CKE. 9. CDI_CTRL = CI(CTRL) - 0.5 × (CI(CLK_t) + CI(CLK_c)). 10. CDI_ADD_CMD applies to A[15:0], BA1:0], RAS_n, CAS_n and WE_n. 11. CDI_ADD_CMD = CI(ADD_CMD) - 0.5 × (CI(CLK_t) + CI(CLK_c)). 298 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Thermal Characteristics 12. Maximum external load capacitance on ZQ pin: 5pF. 13. Only applicable if TEN pin does not have an internal pull-up. Thermal Characteristics Table 127: Thermal Characteristics Parameter/Condition Value Operating case temperature: Commercial 0 to 85 °C TC 1, 2, 3 0 to 95 °C TC 1, 2, 3, 4 Operating case temperature: Industrial –40 to 85 °C TC 1, 2, 3 –40 to 95 °C TC 1, 2, 3, 4 –40 to 85 °C TC 1, 2, 3 –40 to 105 °C TC 1, 2, 3, 4 °C/W ΘJC 5 °C/W ΘJC 5 Operating case temperature: Automotive Junction-to-case (TOP) Die Rev A Junction-to-case (TOP) Die Rev B 78-ball “HX” 4.4 96-ball “HA” 3.6 78-ball “RH” TBD 96-ball “GE” TBD Units Symbol Notes 1. MAX operating case temperature. TC is measured in the center of the package. 2. A thermal solution must be designed to ensure the DRAM device does not exceed the maximum TC during operation. 3. Device functionality is not guaranteed if the DRAM device exceeds the maximum TC during operation. 4. If TC exceeds 85°C, the DRAM must be refreshed externally at 2x refresh, which is a 3.9μs interval refresh rate. 5. The thermal resistance data is based off of a number of samples from multiple lots and should be viewed as a typical number. Notes: Figure 233: Thermal Measurement Point TC test point (L/2) L (W/2) W PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 299 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Measurement Conditions Current Specifications – Measurement Conditions IDD, IPP, and IDDQ Measurement Conditions IDD, IPP, and IDDQ measurement conditions, such as test load and patterns, are defined in this section. • IDD currents (IDD0, IDD1, IDD2N, IDD2NT, IDD2P, IDD2Q, IDD3N, IDD3P, IDD4R, IDD4W, IDD5B, IDD6N, IDD6E, IDD6R, IDD7, and IDD8) are measured as time-averaged currents with all VDD balls of the device under test grouped together. IPP and IDDQ currents are not included in IDD currents. • IPP currents are IPPSB for standby cases (IDD2N, IDD2NT, IDD2P, IDD2Q, IDD3N, IDD3P, IDD8); IPP0 for active cases (IDD0,IDD1, IDD4R, IDD4W); IPP5B and IPP6N for self refresh cases (IDD6N, IDD6E, IDD6R), and IPP7. These have the same definitions as the I DD currents referenced but are measured on the V PP supply. • IDDQ currents (IDDQ2NT and IDDQ4R) are measured as time-averaged currents with VDDQ balls of the device under test grouped together. IDD current is not included in IDDQ currents. Note: IDDQ values cannot be directly used to calculate the I/O power of the device. They can be used to support correlation of simulated I/O power to actual I/O power. In DRAM module application, IDDQ cannot be measured separately because V DD and V DDQ are using a merged-power layer in the module PCB. The following definitions apply for IDD, IDDP and IDDQ measurements. • • • • • • • • • “0” and “LOW” are defined as V IN ≤VIL(AC)max “1” and “HIGH” are defined as V IN ≥VIH(AC)min “Midlevel” is defined as inputs V REF = V DD/2 Timings used for IDD, IDDP and IDDQ measurement-loop patterns are provided in the Current Test Definition and Patterns section. Basic IDD, IPP, and IDDQ measurement conditions are described in the Current Test Definition and Patterns section. Detailed IDD, IPP, and IDDQ measurement-loop patterns are described in the Current Test Definition and Patterns section. Current measurements are done after properly initializing the device. This includes, but is not limited to, setting: RON = RZQ/7 (34 ohm in MR1); Qoff = 0B (output buffer enabled in MR1); RTT(NOM) = RZQ/6 (40 ohm in MR1); RTT(WR) = RZQ/2 (120 ohm in MR2); RTT(Park) = disabled; TDQS feature disabled in MR1; CRC disabled in MR2; CA parity feature disabled in MR3; Gear-down mode disabled in MR3; Read/Write DBI disabled in MR5; DM disabled in MR5 Define D = {CS_n, RAS_n, CAS_n, WE_n}: = {HIGH, LOW, LOW, LOW}; apply BG/BA changes when directed. Define D_n = {CS_n, RAS_n, CAS_n, WE_n}: = {HIGH, HIGH, HIGH, HIGH}; apply invert of BG/BA changes when directed above. Note: The measurement-loop patterns must be executed at least once before actual current measurements can be taken. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 300 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Measurement Conditions Figure 234: Measurement Setup and Test Load for IDDx, IDDPx, and IDDQx IDD VDD RESET_n CK_t/CK_c IPP IDDQ VPP VDDQ DDR4 SDRAM CKE CS_n C ACT_n, RAS_n, CAS_n, WE_n A, BG, BA ODT ZQ V DQS_t, DQS_c DQ DM_n VSSQ SS Figure 235: Correlation: Simulated Channel I/O Power to Actual Channel I/O Power Applic ation-s pe c ific memory c ha nne l env ironmen t C hanne l I/O pow er simulation I DD Q tes t loa d I DD Q simulation IDD Q meas ure ment C or relation C orre c tion C hanne l I/O pow er n umber Note: 1. Supported by IDDQ measurement. IDD Definitions Table 128: Basic IDD, IPP, and IDDQ Measurement Conditions Symbol Description IDD0 Operating One Bank Active-Precharge Current (AL = 0) CKE: HIGH; External clock: On; tCK, nRC, nRAS, CL: see the previous table; BL: 8;1 AL: 0; CS_n: HIGH between ACT and PRE; Command, address, bank group address, bank address inputs: partially toggling according to the next table; Data I/O: VDDQ; DM_n: stable at 0; Bank activity: cycling with one bank active at a time: 0, 0, 1, 1, 2, 2, ... (see the IDD0 Measurement-Loop Pattern table); Output buffer and RTT: enabled in mode registers;2 ODT signal: stable at 0; Pattern details: see the IDD0 Measurement-Loop Pattern table PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 301 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Measurement Conditions Table 128: Basic IDD, IPP, and IDDQ Measurement Conditions (Continued) Symbol Description IPP0 Operating One Bank Active-Precharge IPP Current (AL = 0) Same conditions as IDD0 above IDD1 Operating One Bank Active-Read-Precharge Current (AL = 0) CKE: HIGH; External clock: on; tCK, nRC, nRAS, nRCD, CL: see the previous table; BL: 8;1, 5 AL: 0; CS_n: HIGH between ACT, RD, and PRE; Command, address, bank group address, bank address inputs, Data I/O: partially toggling according to the IDD1 Measurement-Loop Pattern table; DM_n: stable at 0; Bank activity: cycling with one bank active at a time: 0, 0, 1, 1, 2, 2, ... (see the following table); Output buffer and RTT: enabled in mode registers;2 ODT Signal: stable at 0; Pattern details: see the IDD1 Measurement-Loop Pattern table IDD2N Precharge Standby Current (AL = 0) CKE: HIGH; External clock: On; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command, address, bank group address, bank address Inputs: partially toggling according to the IDD2N and IDD3N Measurement-Loop Pattern table; Data I/O: VDDQ; DM_n: stable at 1; Bank activity: all banks closed; Output buffer and RTT: enabled in mode registers;2 ODT signal: stable at 0; Pattern details: see the IDD2N and IDD3N MeasurementLoop Pattern table IDD2NT Precharge Standby ODT Current CKE: HIGH; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command, address, bank gropup address, bank address inputs: partially toggling according to the IDD2NT and IDDQ2NT Measurement-Loop Pattern table; Data I/O: VSSQ; DM_n: stable at 1; Bank activity: all banks closed; Output buffer and RTT: enabled in mode registers;2 ODT signal: toggling according to the IDD2NT and IDDQ2NT MeasurementLoop Pattern table; Pattern details: see the IDD2NT and IDDQ2NT Measurement-Loop Pattern table IDDQ2NT Precharge Standby ODT IDDQ Current Has the same definition as IDD2NT above, with the exception of measuring IDDQ current instead of IDD current IDD2P Precharge Power-Down Current CKE: LOW; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command, address, bank group address, bank address inputs: stable at 0; Data I/O: VDDQ; DM_n: stable at 1; Bank activity: all banks closed; Output buffer and RTT: Enabled in mode registers;2 ODT signal: stable at 0 IDD2Q Precharge Quiet Standby Current CKE: HIGH; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command, address, bank group address, bank address inputs: stable at 0; Data I/O: VDDQ; DM_n: stable at 1; Bank activity: all banks closed; Output buffer and RTT: Enabled in mode registers;2 ODT signal: stable at 0 IDD3N Active Standby Current (AL = 0) CKE: HIGH; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command, address, bank group address, bank address inputs: partially toggling according to the IDD2N and IDD3N Measurement-Loop Pattern table; Data I/O: VDDQ; DM_n: stable at 1; Bank activity: all banks open; Output buffer and RTT: Enabled in mode registers;2 ODT signal: stable at 0; Pattern details: see the IDD2N and IDD3N MeasurementLoop Pattern table IPPSB Active Standby IPPSB Current (AL = 0) Same conditions as IDD3N above IDD3P Active Power-Down Current (AL = 0) CKE: LOW; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command, address, bank group address, bank address inputs: stable at 1; Data I/O: VDDQ; DM_n: stable at 1; Bank activity: all banks open; Output buffer and RTT: Enabled in mode registers;2 ODT signal: stable at 0 PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 302 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Measurement Conditions Table 128: Basic IDD, IPP, and IDDQ Measurement Conditions (Continued) Symbol Description IDD4R Operating Burst Read Current (AL = 0) CKE: HIGH; External clock: on; tCK, CL: see the previous table; BL: 8;15 AL: 0; CS_n: HIGH between RD; Command, address, bank group address, bank address inputs: partially toggling according to the IDD4R and IDDQ4R Measurement-Loop Pattern table; Data I/O: seamless read data burst with different data between one burst and the next one according to the IDD4R and IDDQ4R Measurement-Loop Pattern table; DM_n: stable at 1; Bank activity: all banks open, RD commands cycling through banks: 0, 0, 1, 1, 2, 2, ... (see the IDD4R and IDDQ4R Measurement-Loop Pattern table); Output buffer and RTT: Enabled in mode registers;2 ODT signal: stable at 0; Pattern details: see the IDD4R and IDDQ4R Measurement-Loop Pattern table IDDQ4R Operating Burst Read IDDQ Current Has the same definition as IDD4R, with the exception of measuring IDDQ current instead of IDD current IDD4W Operating Burst Write Current (AL = 0) CKE: HIGH; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: HIGH between WR; Command, address, bank group address, bank address inputs: partially toggling according to the IDD4W Measurement-Loop Pattern table; Data I/O: seamless write data burst with different data between one burst and the next one according to the IDD4W Measurement-Loop Pattern table; DM: stable at 0; Bank activity: all banks open, WR commands cycling through banks: 0, 0, 1, 1, 2, 2, ... (see IDD4W Measurement-Loop Pattern table); Output buffer and RTT: enabled in mode registers (see note2); ODT signal: stable at HIGH; Pattern details: see the IDD4W Measurement-Loop Pattern table IDD5B Burst Refresh Current (1X REF) CKE: HIGH; External clock: on; tCK, CL, nRFC: see the previous table; BL: 8;1 AL: 0; CS_n: HIGH between REF; Command, address, bank group address, bank address inputs: partially toggling according to the IDD5B Measurement-Loop Pattern table; Data I/O: VDDQ; DM_n: stable at 1; Bank activity: REF command every nRFC (see the IDD5B Measurement-Loop Pattern table); Output buffer and RTT: enabled in mode registers2; ODT signal: stable at 0; Pattern details: see the IDD5B Measurement-Loop Pattern table IPP5B Burst Refresh Current (1X REF) Same conditions as IDD5B above IDD6N Self Refresh Current: Normal Temperature Range TC: 0–85°C; Auto self refresh (ASR): disabled;3 Self refresh temperature range (SRT): normal;4 CKE: LOW; External clock: off; CK_t and CK_c: LOW; CL: see the table above; BL: 8;1 AL: 0; CS_n, command, address, bank group address, bank address, data I/O: VDDQ; DM_n: stable at 1; Bank activity: SELF REFRESH operation; Output buffer and RTT: enabled in mode registers;2 ODT signal: midlevel IPP6N Self Refresh IPP Current: Normal Temperature Range Same conditions as IDD6N above IDD6E Self Refresh Current: Extended Temperature Range 4 TC: 0–95°C; Auto self refresh (ASR): disabled4; Self refresh temperature range (SRT): extended;4 CKE: LOW; External clock: off; CK_t and CK_c: LOW; CL: see the previous table; BL: 8;1 AL: 0; CS_n, command, address, group bank address, bank address, data I/O: VDDQ; DM_n: stable at 1; Bank activity: EXTENDED TEMPERATURE SELF REFRESH operation; Output buffer and RTT: enabled in mode registers;2 ODT signal: midlevel IDD6R Self Refresh Current: Reduced Temperature Range TC: 0–45°C; Auto self refresh (ASR): disabled; Self refresh temperature range (SRT): reduced;4 CKE: LOW; External clock: off; CK_t and CK_c: LOW; CL: see the previous table; BL: 8;1 AL: 0; CS_n, command, address, bank group address, bank address, data I/O: VDDQ; DM_n: stable at 1; Bank activity: EXTENDED TEMPERATURE SELF REFRESH operation; Output buffer and RTT: enabled in mode registers;2 ODT signal: midlevel PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 303 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Measurement Conditions Table 128: Basic IDD, IPP, and IDDQ Measurement Conditions (Continued) Symbol Description IDD7 Operating Bank Interleave Read Current CKE: HIGH; External clock: on; tCK, nRC, nRAS, nRCD, nRRD, nFAW, CL: see the previous table; BL: 8;15 AL: CL 1; CS_n: HIGH between ACT and RDA; Command, address, group bank adress, bank address inputs: partially toggling according to the IDD7 Measurement-Loop Pattern table; Data I/O: read data bursts with different data between one burst and the next one according to the IDD7 Measurement-Loop Pattern table; DM: stable at 1; Bank activity: two times interleaved cycling through banks (0, 1, ...7) with different addressing, see the IDD7 Measurement-Loop Pattern table; Output buffer and RTT: enabled in mode registers;2 ODT signal: stable at 0; Pattern details: see the IDD7 Measurement-Loop Pattern table IPP7 Operating Bank Interleave Read IPP Current Same conditions as IDD7 above IDD8 Maximum Power Down Current Place DRAM in MPSM then CKE: HIGH; External clock: on; tCK, CL: see the previous table; BL: 8;1 AL: 0; CS_n: stable at 1; Command, address, bank group address, bank address inputs: stable at 0; Data I/O: VDDQ; DM_n: stable at 1; Bank activity: all banks closed; Output buffer and RTT: Enabled in mode registers;2 ODT signal: stable at 0 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Burst length: BL8 fixed by MRS: set MR0[1:0] 00. 2. Output buffer enable: set MR1[12] 0 (output buffer enabled); set MR1[2:1] 00 (RON = RZQ/7); RTT(NOM) enable: set MR1[10:8] 011 (RZQ/6); RTT(WR) enable: set MR2[11:9] 001 (RZQ/2), and RTT(Park) enable: set MR5[8:6] 000 (disabled). 3. Auto self refresh (ASR): set MR2[6] 0 to disable or MR2[6] 1 to enable feature. 4. Self refresh temperature range (SRT): set MR2[7] 0 for normal or MR2[7] 1 for extended temperature range. 5. READ burst type: Nibble sequential, set MR0[3] 0. 304 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Patterns and Test Conditions Current Specifications – Patterns and Test Conditions Current Test Definitions and Patterns Sub-Loop Cycle Number Command CS_n ACT_n RAS_n/A16 CAS_n/A15 WE_n/A14 ODT BG[1:0]2 BA[1:0] A12/BC_n A[17,13,11]] A[10]/AP A[9:7] A[6:3] A[2:0] CKE CK_t, CK_c Table 129: IDD0 and IPP0 Measurement-Loop Pattern1 Data3 0 0 ACT 0 0 0 0 0 0 0 0 0 0 0 0 0 0 – 1, 2 D, D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 – 3, 4 D_n, D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 – PRE 0 1 0 ... Repeat pattern 1...4 until nRAS - 1; truncate if necessary Static High Toggling nRAS 1 0 0 0 0 0 0 0 0 0 0 ... Repeat pattern 1...4 until nRC - 1; truncate if necessary 1 1 × nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 1 instead 2 2 × nRC Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead 3 3 × nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 3 instead 4 4 × nRC Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead 5 5 × nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 2 instead 6 6 × nRC Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead 7 7 × nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 0 instead 8 8 × nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4 9 9 × nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 1 instead4 10 10 × nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4 11 11 × nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 3 instead4 12 12 × nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4 13 13 × nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 2 instead4 14 14 × nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4 15 15 × nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 0 instead4 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. 2. 3. 4. – DQS_t, DQS_c are VDDQ. BG1 is a "Don't Care" for x16 devices. DQ signals are VDDQ. For x4 and x8 only. 305 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Patterns and Test Conditions Sub-Loop Cycle Number Command CS_n ACT_n RAS_n/A16 CAS_n/A15 WE_n/A14 ODT BG[1:0]2 BA[1:0] A12/BC_n A[17,13,11]] A[10]/AP A[9:7] A[6:3] A[2:0] CKE CK_c, CK_t, Table 130: IDD1 Measurement-Loop Pattern1 Data3 0 0 ACT 0 0 0 0 0 0 0 0 0 0 0 0 0 0 – 1, 2 D, D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 – 3, 4 D_n, D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 – RD 0 ... Repeat pattern 1...4 until nRCD - AL - 1; truncate if necessary nRCD - AL ... PRE ... 1 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 D0 = 00, D1 = FF, D2 = FF, D3 = 00, D4 = FF, D5 = 00, D5 = 00, D7 = FF 1 × nRC + 0 ACT 0 0 0 1 1 0 1 1 0 0 0 0 0 0 – 1 × nRC + 1, 2 D, D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 – 1 1 1 1 1 0 3 3 0 0 0 7 F 0 – ... Repeat pattern nRC + 1...4 until 1 × nRC + nRAS - 1; truncate if necessary 1 × nRC +nRCD - AL Static High 0 Repeat pattern 1...4 until nRC - 1; truncate if necessary 1 × nRC + 3, D_n, D_n 4 Toggling 1 Repeat pattern 1...4 until nRAS - 1; truncate if necessary nRAS 1 1 RD ... 0 1 1 0 1 0 1 1 0 0 0 0 0 0 0 0 Repeat pattern 1...4 until nRAS - 1; truncate if necessary 1 × nRC + nRAS ... PRE 0 1 0 1 0 0 1 1 0 0 0 0 Repeat pattern nRC + 1...4 until 2 × nRC - 1; truncate if necessary 2 2 × nRC Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead 3 3 × nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 3 instead 4 4 × nRC Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead 5 5 × nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 2 instead 6 6 × nRC Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead 7 7 × nRC Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 0 instead 8 9 × nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4 9 10 × nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 1 instead4 10 11 × nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4 11 12 × nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 3 instead4 12 13 × nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4 13 14 × nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 2 instead4 14 15 × nRC Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4 15 16 × nRC Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 0 instead4 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN D0 = FF, D1 = 00, D2 = 00, D3 = FF, D4 = 00, D5 = FF, D5 = FF, D7 = 00 1. DQS_t, DQS_c are VDDQ when not toggling. 306 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Patterns and Test Conditions 2. BG1 is a "Don't Care" for x16 devices. 3. DQ signals are VDDQ except when burst sequence drives each DQ signal by a READ command. 4. For x4 and x8 only. Static High Toggling 0 A[2:0] A[6:3] A[9:7] A[10]/AP A[17,13,11]] A12/BC_n BA[1:0] BG[1:0]2 ODT WE_n/A14 CAS_n/A15 RAS_n/A16 ACT_n CS_n Command Cycle Number Sub-Loop CKE CK_c, CK_t, Table 131: IDD2N, IDD3N, and IPP3P Measurement-Loop Pattern1 Data3 0 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 – 1 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 – 2 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 – 3 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 – 1 4–7 Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 1 instead 2 8–11 Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead 3 12–15 Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 3 instead 4 16–19 Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead 5 20–23 Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 2 instead 6 24–27 Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead 7 28–31 Repeat sub-loop 0, use BG[1:0] = 1, use BA[1:0] = 0 instead 8 32–35 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4 9 36–39 Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 1 instead4 10 40–43 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4 11 44–47 Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 3 instead4 12 48–51 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4 13 52–55 Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 2 instead4 14 56–59 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4 15 60–63 Repeat sub-loop 0, use BG[1:0] = 3, use BA[1:0] = 0 instead4 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. 2. 3. 4. DQS_t, DQS_c are VDDQ. BG1 is a "Don't Care" for x16 devices. DQ signals are VDDQ. For x4 and x8 only. 307 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Patterns and Test Conditions Sub-Loop Cycle Number Command CS_n ACT_n RAS_n/A16 CAS_n/A15 WE_n/A14 ODT BG[1:0]2 BA[1:0] A12/BC_n A[17,13,11]] A[10]/AP A[9:7] A[6:3] A[2:0] CKE Static High Toggling CK_c, CK_t, Table 132: IDD2NT and IDDQ2NT Measurement-Loop Pattern1 Data3 0 0 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 – 1 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 – 2 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 – 3 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 – 1 4–7 Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 1, use BA[1:0] = 1 instead 2 8–11 Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 0, use BA[1:0] = 2 instead 3 12–15 Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 1, use BA[1:0] = 3 instead 4 16–19 Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 0, use BA[1:0] = 1 instead 5 20–23 Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 1, use BA[1:0] = 2 instead 6 24–27 Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 0, use BA[1:0] = 3 instead 7 28–31 Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 1, use BA[1:0] = 0 instead 8 32–35 Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4 9 36–39 Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 3, use BA[1:0] = 1 instead4 10 40–43 Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4 11 44–47 Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 3, use BA[1:0] = 3 instead4 12 48–51 Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4 13 52–55 Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 3, use BA[1:0] = 2 instead4 14 56–59 Repeat sub-loop 0 with ODT = 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4 15 60–63 Repeat sub-loop 0 with ODT = 1, use BG[1:0] = 3, use BA[1:0] = 0 instead4 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. 2. 3. 4. DQS_t, DQS_c are VSSQ. BG1 is a "Don't Care" for x16 devices. DQ signals are VSSQ. For x4 and x8 only. 308 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Patterns and Test Conditions Sub-Loop Cycle Number Command CS_n ACT_n RAS_n/A16 CAS_n/A15 WE_n/A14 ODT BG[1:0]2 BA[1:0] A12/BC_n A[17,13,11]] A[10]/AP A[9:7] A[6:3] A[2:0] CKE CK_c, CK_t, Table 133: IDD4R and IDDQ4R Measurement-Loop Pattern1 0 0 RD 0 1 1 0 1 0 0 0 0 0 0 0 0 0 1 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 2, 3 D_n, D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 4 RD 0 1 1 0 1 0 1 1 0 0 0 7 F 0 5 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 6, 7 D_n, D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 Static High Toggling 1 2 8–11 Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead 3 12–15 Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 3 instead 4 16–19 Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead 5 20–23 Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 2 instead 6 24–27 Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead 7 28–31 Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 0 instead 8 32–35 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4 9 36–39 Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 1 instead4 10 40–43 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4 11 44–47 Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 3 instead4 12 48–51 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4 13 52–55 Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 2 instead4 14 56–59 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4 15 60–63 Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 0 instead4 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Data3 D0 = 00, D1 = FF, D2 = FF, D3 = 00, D4 = FF, D5 = 00, D5 = 00, D7 = FF D0 = FF, D1 = 00 D2 = 00, D3 = FF D4 = 00, D5 = FF D5 = FF, D7 = 00 1. DQS_t, DQS_c are VDDQ when not toggling. 2. BG1 is a "Don't Care" for x16 devices. 3. Burst sequence driven on each DQ signal by a READ command. Outside burst operation, DQ signals are VDDQ. 4. For x4 and x8 only. 309 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Patterns and Test Conditions Cycle Number Command CS_n ACT_n WE_n/A14 ODT BG[1:0]2 BA[1:0] A12/BC_n A[17,13,1 1]] A[10]/AP A[9:7] A[6:3] A[2:0] 0 0 WR 0 1 1 0 0 1 0 0 0 0 0 0 0 0 1 D 1 0 0 0 0 1 0 0 0 0 0 0 0 0 2, 3 D_n, D_n 1 1 1 1 0 1 3 3 0 0 0 7 F 0 4 WR 0 1 1 0 0 1 1 1 0 0 0 7 F 0 5 D 1 0 0 0 0 1 0 0 0 0 0 0 0 0 6, 7 D_n, D_n 1 1 1 1 0 1 3 3 0 0 0 7 F 0 Static High Toggling 1 RAS_n/A1 6 CAS_n/A1 5 Sub-Loop CKE CK_c, CK_t, Table 134: IDD4W Measurement-Loop Pattern1 2 8–11 Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead 3 12–15 Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 3 instead 4 16–19 Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead 5 20–23 Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 2 instead 6 24–27 Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead 7 28–31 Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 0 instead 8 32–35 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4 9 36–39 Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 1 instead4 10 40–43 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4 11 44–47 Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 3 instead4 12 48–51 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4 13 52–55 Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 2 instead4 14 56–59 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4 15 60–63 Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 0 instead4 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Data3 D0 = 00, D1 = FF, D2 = FF, D3 = 00, D4 = FF, D5 = 00, D5 = 00, D7 = FF D0 = FF, D1 = 00 D2 = 00, D3 = FF D4 = 00, D5 = FF D5 = FF, D7 = 00 1. DQS_t, DQS_c are VDDQ when not toggling. 2. BG1 is a "Don't Care" for x16 devices. 3. Burst sequence driven on each DQ signal by WRITE command. Outside burst operation, DQ signals are VDDQ. 4. For x4 and x8 only. 310 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Patterns and Test Conditions Sub-Loop Cycle Number Command CS_n ACT_n RAS_n/A16 CAS_n/A15 WE_n/A14 ODT BG[1:0]3 BA[1:0] A12/BC_n A[17,13,11]] A[10]/AP A[9:7] A[6:3] A[2:0] CKE CK_c, CK_t, Table 135: IDD4Wc Measurement-Loop Pattern1 0 0 WR 0 1 1 0 0 1 0 0 0 0 0 0 0 0 1, 2 D, D 1 0 0 0 0 1 0 0 0 0 0 0 0 0 3, 4 D_n, D_n 1 1 1 1 0 1 3 3 0 0 0 7 F 0 Static High Toggling 1 5 WR 0 1 1 0 0 1 1 1 0 0 0 7 F 0 6, 7 D, D 1 0 0 0 0 1 0 0 0 0 0 0 0 0 8, 9 D_n, D_n 1 1 1 1 0 1 3 3 0 0 0 7 F 0 2 10–14 Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead 3 15–19 Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 3 instead 4 20–24 Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead 5 25–29 Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 2 instead 6 30–34 Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead 7 35–39 Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 0 instead 8 40–44 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead4 9 45–49 Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 1 instead4 10 50–54 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead4 11 55–59 Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 3 instead4 12 60–64 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead4 13 65–69 Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 2 instead4 14 70–74 Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead4 15 75–79 Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 0 instead4 Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN Data4 D0 = 00, D1 = FF, D2 = FF, D3 = 00, D4 = FF, D5 = 00, D8 = CRC D0 = FF, D1 = 00, D2 = 00, D3 = FF, D4 = 00, D5 = FF, D5 = FF, D7 = 00 D8 = CRC 1. 2. 3. 4. Pattern provided for reference only. DQS_t, DQS_c are VDDQ when not toggling. BG1 is a "Don't Care" for x16 devices. Burst sequence driven on each DQ signal by WRITE command. Outside burst operation, DQ signals are VDDQ. 5. For x4 and x8 only. 311 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Patterns and Test Conditions Sub-Loop Cycle Number Command CS_n ACT_n RAS_n/A16 CAS_n/A15 WE_n/A14 ODT BG[1:0]2 BA[1:0] A12/BC_n A[17,13,11]] A[10]/AP A[9:7] A[6:3] A[2:0] CKE Data3 0 0 REF 0 1 0 0 1 0 0 0 0 0 0 0 0 0 – 1 1 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 – 2 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 – 3 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 – 4 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 – Static High Toggling CK_c, CK_t, Table 136: IDD5b Measurement-Loop Pattern1 2 5–8 Repeat pattern 1...4, use BG[1:0] = 1, use BA[1:0] = 1 instead 9–12 Repeat pattern 1...4, use BG[1:0] = 0, use BA[1:0] = 2 instead 13–16 Repeat pattern 1...4, use BG[1:0] = 1, use BA[1:0] = 3 instead 17–20 Repeat pattern 1...4, use BG[1:0] = 0, use BA[1:0] = 1 instead 21–24 Repeat pattern 1...4, use BG[1:0] = 1, use BA[1:0] = 2 instead 25–28 Repeat pattern 1...4, use BG[1:0] = 0, use BA[1:0] = 3 instead 29–32 Repeat pattern 1...4, use BG[1:0] = 1, use BA[1:0] = 0 instead 33–36 Repeat pattern 1...4, use BG[1:0] = 2, use BA[1:0] = 0 instead4 37–40 Repeat pattern 1...4, use BG[1:0] = 3, use BA[1:0] = 1 instead4 41–44 Repeat pattern 1...4, use BG[1:0] = 2, use BA[1:0] = 2 instead4 45–48 Repeat pattern 1...4, use BG[1:0] = 3, use BA[1:0] = 3 instead4 49–52 Repeat pattern 1...4, use BG[1:0] = 2, use BA[1:0] = 1 instead4 53–56 Repeat pattern 1...4, use BG[1:0] = 3, use BA[1:0] = 2 instead4 57–60 Repeat pattern 1...4, use BG[1:0] = 2, use BA[1:0] = 3 instead4 61–64 Repeat pattern 1...4, use BG[1:0] = 3, use BA[1:0] = 0 instead4 65...nRFC 1 Repeat sub-loop 1; truncate if necessary Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. 2. 3. 4. DQS_t, DQS_c are VDDQ. BG1 is a "Don't Care" for x16 devices. DQ signals are VDDQ. For x4 and x8 only. 312 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Patterns and Test Conditions Sub-Loop Cycle Number Command CS_n ACT_n RAS_n/A16 CAS_n/A15 WE_n/A14 ODT BG[1:0]2 BA[1:0] A12/BC_n A[17,13,11]] A[10]/AP A[9:7] A[6:3] A[2:0] CKE CK_t, CK_c Table 137: IDD7 Measurement-Loop Pattern1 Data3 0 0 ACT 0 0 0 0 0 0 0 0 0 0 0 0 0 0 – 1 RDA 0 1 1 0 1 0 0 0 0 0 1 0 0 0 2 D 1 0 0 0 0 0 0 0 0 0 0 0 0 0 – 3 D_n 1 1 1 1 1 0 3 3 0 0 0 7 F 0 – ... Static High Toggling 1 Repeat pattern 2...3 until nRRD - 1, if nRRD > 4. Truncate if necessary nRRD ACT 0 0 0 0 0 0 1 1 0 0 0 0 0 0 nRRD+1 RDA 0 1 1 0 1 0 1 1 0 0 1 0 0 0 – ... Repeat pattern 2...3 until 2 × nRRD - 1, if nRRD > 4. Truncate if necessary 2 2 × nRRD Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 2 instead 3 3 × nRRD Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 3 instead 4 4 × nRRD Repeat pattern 2...3 until nFAW - 1, if nFAW > 4 × nRRD. Truncate if necessary 5 nFAW Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 1 instead 6 nFAW + nRRD Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 2 instead 7 nFAW + 2 × nRRD Repeat sub-loop 0, use BG[1:0] = 0, use BA[1:0] = 3 instead 8 nFAW + 3 × nRRD Repeat sub-loop 1, use BG[1:0] = 1, use BA[1:0] = 0 instead 9 nFAW + 4 × nRRD Repeat sub-loop 4 10 2 × nFAW Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 0 instead 11 2 × nFAW + nRRD Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 1 instead 12 2 × nFAW + 2 × nRRD Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 2 instead 13 2 × nFAW + 3 × nRRD Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 3 instead 14 2 × nFAW + 4 × nRRD Repeat sub-loop 4 15 3 × nFAW Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 1 instead 16 3 × nFAW + nRRD Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 2 instead 17 3 × nFAW + 2 × nRRD Repeat sub-loop 0, use BG[1:0] = 2, use BA[1:0] = 3 instead 18 3 × nFAW + 3 × nRRD Repeat sub-loop 1, use BG[1:0] = 3, use BA[1:0] = 0 instead 19 3 × nFAW + 4 × nRRD Repeat sub-loop 4 20 4 × nFAW Repeat pattern 2...3 until nRC - 1, if nRC > 4 × nFAW. Truncate if necessary Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. DQS_t, DQS_c are VDDQ. 2. BG1 is a "Don't Care" for x16 devices. 3. DQ signals are VDDQ except when burst sequence drives each DQ signal by a READ command. 313 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Patterns and Test Conditions 4. For x4 and x8 only. IDD Specifications Table 138: Timings used for IDD, IPP, and IDDQ Measurement-Loop Patterns 17-17-17 17-17-17 19-19-19 20-20-20 24-24-24 13 14 14 15 16 15 16 17 17 18 19 20 22 24 CK CWL 9 11 11 10 12 12 11 14 14 12 16 16 14 18 18 16 20 20 CK nRCD 10 11 12 12 13 14 14 15 16 15 16 17 17 18 19 20 22 24 CK nRC 38 39 40 44 45 46 50 51 52 54 55 57 60 61 62 72 74 76 CK nRP 10 11 12 12 13 14 14 15 16 15 16 17 17 18 19 20 22 24 CK nRAS nFAW 0.75 22-22-22 15-15-15 12 0.833 18-18-18 16-16-16 12 0.937 16-16-16 14-14-14 11 1.071 15-15-15 14-14-14 DDR4-3200 10 1.25 13-13-13 DDR4-2666 12-12-12 DDR4-2400 12-12-12 DDR4-2133 CL tCK 11-11-11 DDR4-1866 Uni t Symbol 10-10-10 DDR4-1600 0.625 ns 28 32 36 39 43 52 CK x41 16 16 16 16 16 16 CK x8 20 22 23 26 28 34 CK x16 28 28 32 36 40 48 CK nRRD_ x4 S x8 4 4 4 4 4 4 CK 4 4 4 4 4 4 CK x16 5 5 6 7 7 9 CK nRRD_ x4 L x8 5 5 6 6 7 8 CK 5 5 6 6 7 8 CK x16 6 6 7 8 9 11 CK nCCD_S 4 4 4 4 4 4 CK nCCD_L 5 5 6 6 7 8 CK nWTR_S 2 3 3 3 4 4 CK nWTR_L 6 7 8 9 10 12 CK nRFC 2Gb 128 150 171 193 214 256 CK nRFC 4Gb 208 243 278 313 347 416 CK nRFC 8Gb 280 327 374 421 467 560 CK nRFC 16Gb 440 514 587 660 733 880 CK Note: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. 1KB based x4 use same numbers of clocks for nFAW as the x8. 314 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Limits Current Specifications – Limits Table 139: IDD, IPP, and IDDQ Current Limits – Rev. A Symbol Width DDR4-1600 DDR4-1866 DDR4-2133 DDR4-2400 Unit IDD0: One bank ACTIVATE-to-PRECHARGE current x4, x8 58 58 60 64 mA x16 66 66 68 70 mA IPP0: One bank ACTIVATE-to-PRECHARGE IPP current x4, x8 4 4 4 4 mA x16 4.6 4.6 4.6 4.6 mA IDD1: One bank ACTIVATE-to-READ-toPRECHARGE current x4, x8 63 63 65 68 mA IDD2N: Precharge standby current IDD2NT: Precharge standby ODT current x16 78 78 80 83 mA ALL 44 44 46 50 mA x4, x8 50 50 54 58 mA x16 60 60 64 68 mA IDD2P: Precharge power-down current ALL 30 30 30 32 mA IDD2Q: Precharge quiet standby current ALL 39 39 39 41 mA IDD3N: Active standby current ALL 61 61 63 67 mA IPP3N: Active standby IPP current ALL 3 3 3 3 mA IDD3P: Active power-down current ALL 44 44 44 44 mA x4, x8 140 140 150 160 mA x16 200 200 215 230 mA IDD4W: Burst write current x4, x8 156 156 176 196 mA x16 246 246 276 314 mA IDD5B: Burst refresh current (1X REF) x4, x8 190 190 190 192 mA x16 190 190 190 192 mA x4, x8 22 22 22 22 mA IDD4R: Burst read current IPP5B: Burst refresh IPP current (1X REF) x16 22 22 22 22 mA IDD6N: Self refresh current; 0–85°C1 ALL 20 20 20 20 mA IDD6E: Self refresh current; 0–95°C2 ALL 27 27 27 27 mA IDD6R: Self refresh current; 0–45C3, 4 ALL 10 10 10 10 mA (25°C)4 ALL 9 9 9 9 mA IDD6A: Auto self refresh current (45°C)4 ALL 10 10 10 10 mA IDD6A: Auto self refresh current (75°C)4 ALL 16 16 16 16 mA IDD7: Bank interleave read current x4, x8 160 160 185 210 mA x16 230 230 240 250 mA IPP7: Bank interleave read IPP current x4, x8 10 10 12 14 mA x16 12 12 14 16 mA ALL 18 18 18 18 mA IDD6A: Auto self refresh current IDD8: Maximum power-down current Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Applicable for MR2 settings A7 = 0 and A6 = 0; manual mode with normal temperature range of operation (0–85°C). 2. Applicable for MR2 settings A7 = 1 and A7 = 0; manual mode with extended temperature range of operation (0–95°C). 315 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Limits 3. Applicable for MR2 settings A7 = 0 and A7 = 1; manual mode with reduced temperature range of operation (0–45°C). 4. IDD6R and IDD6A values are typical. 5. When additive latency is enabled for IDD0, current changes by approximately 0%. 6. When additive latency is enabled for IDD1 , current changes by approximately +5% (x4/ x8), +4% (x16). 7. When additive latency is enabled for IDD2N , current changes by approximately +0.6%. 8. When DLL is disabled for IDD2N, current changes by approximately 0%. 9. When CAL is enabled for IDD2N, current changes by approximately –44%. 10. When gear-down is enabled for IDD2N, current changes by approximately 0%. 11. When CA parity is enabled for IDD2N, current changes by approximately +14%. 12. When additive latency is enabled for IDD3N, current changes by approximately +0.6%. 13. When additive latency is enabled for IDD4R, current changes by approximately +5%. 14. When read DBI is enabled for IDD4R, current changes by approximately 0%. 15. When read DBI is enabled for IDDQ4R, current changes by approximately –48% (x4/8), – 35% (x16). 16. When additive latency is enabled for IDD4W, current changes by approximately +1.6% (x4/8), +1% (x16). 17. When write DBI is enabled for IDD4W, current changes by approximately 0%. 18. When write CRC is enabled for IDD4W, current changes by approximately –8% (2133/2400), –5% (1600/1866). 19. When CA parity is enabled for IDD4W, current changes by approximately +14% (x8), +8% (x16). 20. When 2X REF is enabled for IDD5B, current changes by approximately –14%. 21. When 4X REF is enabled for IDD5B, current changes by approximately –33%. 22. IPP0 test and limit is applicable for IDD0 and IDD1 conditions. 23. IPP3N test and limit is applicable for all IDD2x, IDD3x, IDD4x, IDD6, and IDD8 conditions; that is, testing IPP3N should satisfy the IPPs for the noted IDD tests. Table 140: IDD, IPP, and IDDQ Current Limits – Rev. B Width DDR4-1866 DDR4-2133 DDR4-2400 DDR4-2666 Uni t IDD0: One bank ACTIVATE-to-PRECHARGE current x4, x8 50 55 60 65 mA x16 60 65 65 70 mA IPP0: One bank ACTIVATE-to-PRECHARGE IPP current x4, x8 3 3 3 3 mA x16 3.6 3.6 3.6 3.6 mA IDD1: One bank ACTIVATE-to-READ-toPRECHARGE current x4, x8 55 60 65 70 mA x16 70 75 75 80 mA ALL 40 42 45 50 mA Symbol IDD2N: Precharge standby current IDD2NT: Precharge standby ODT current x4, x8 45 50 50 55 mA x16 55 60 60 70 mA IDD2P: Precharge power-down current ALL 27 27 29 34 mA IDD2Q: Precharge quiet standby current ALL 35 35 37 40 mA IDD3N: Active standby current ALL 55 55 60 65 mA IPP3N: Active standby IPP current ALL 3 3 3 3 mA IDD3P: Active power-down current ALL 40 40 40 40 mA PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 316 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Limits Table 140: IDD, IPP, and IDDQ Current Limits – Rev. B (Continued) Width DDR4-1866 DDR4-2133 DDR4-2400 DDR4-2666 Uni t x4, x8 125 135 145 170 mA x16 180 195 205 225 mA IDD4W: Burst write current x4, x8 140 155 175 195 mA x16 220 250 285 310 mA IDD5B: Burst refresh current (1X REF) x4, x8 170 170 175 175 mA x16 170 170 175 175 mA x4, x8 22 22 22 22 mA Symbol IDD4R: Burst read current IPP5B: Burst refresh IPP current (1X REF) x16 25 25 25 25 mA IDD6N: Self refresh current; 0–85°C1 ALL 18 18 18 18 mA IDD6E: Self refresh current; 0–95°C2 ALL 24 24 24 24 mA IDD6R: Self refresh current; 0–45C3, 4 ALL 12 12 12 12 mA (25°C)4 ALL 9 9 9 9 mA IDD6A: Auto self refresh current (45°C)4 ALL 12 12 12 12 mA IDD6A: Auto self refresh current (75°C)4 ALL 18 18 18 18 mA IDD7: Bank interleave read current x4, x8 145 165 190 200 mA x16 205 215 225 235 mA IPP7: Bank interleave read IPP current x4, x8 10 12 14 16 mA x16 12 14 16 16 mA ALL 16 16 16 16 mA IDD6A: Auto self refresh current IDD8: Maximum power-down current Notes: PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 1. Applicable for MR2 settings A7 = 0 and A6 = 0; manual mode with normal temperature range of operation (0–85°C). 2. Applicable for MR2 settings A7 = 1 and A7 = 0; manual mode with extended temperature range of operation (0–95°C). 3. Applicable for MR2 settings A7 = 0 and A7 = 1; manual mode with reduced temperature range of operation (0–45°C). 4. IDD6R and IDD6A values are typical. 5. When additive latency is enabled for IDD0, current changes by approximately 0%. 6. When additive latency is enabled for IDD1 , current changes by approximately +5% (x4/ x8), +4% (x16). 7. When additive latency is enabled for IDD2N , current changes by approximately +0.6%. 8. When DLL is disabled for IDD2N, current changes by approximately 0%. 9. When CAL is enabled for IDD2N, current changes by approximately –44%. 10. When gear-down is enabled for IDD2N, current changes by approximately 0%. 11. When CA parity is enabled for IDD2N, current changes by approximately +14%. 12. When additive latency is enabled for IDD3N, current changes by approximately +0.6%. 13. When additive latency is enabled for IDD4R, current changes by approximately +5%. 14. When read DBI is enabled for IDD4R, current changes by approximately 0%. 15. When read DBI is enabled for IDDQ4R, current changes by approximately –48% (x4/8), – 35% (x16). 16. When additive latency is enabled for IDD4W, current changes by approximately +1.6% (x4/8), +1% (x16). 317 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Current Specifications – Limits 17. When write DBI is enabled for IDD4W, current changes by approximately 0%. 18. When write CRC is enabled for IDD4W, current changes by approximately –8% (2133/2400), –5% (1600/1866). 19. When CA parity is enabled for IDD4W, current changes by approximately +14% (x8), +8% (x16). 20. When 2X REF is enabled for IDD5B, current changes by approximately –14%. 21. When 4X REF is enabled for IDD5B, current changes by approximately –33%. 22. IPP0 test and limit is applicable for IDD0 and IDD1 conditions. 23. IPP3N test and limit is applicable for all IDD2x, IDD3x, IDD4x, IDD6, and IDD8 conditions; that is, testing IPP3N should satisfy the IPPs for the noted IDD tests. PDF: 09005aef84af6dd0 4gb_ddr4_dram.pdf - Rev. E 11/15 EN 318 Micron Technology, Inc. reserves the right to change products or specifications without notice. © 2014 Micron Technology, Inc. All rights reserved. 4Gb: x4, x8, x16 DDR4 SDRAM Speed Bin Tables Speed Bin Tables Table 141: DDR4-1600 Speed Bins and Operating Conditions DDR4-1600 Speed Bin CL-nRCD-nRP Parameter -125F -125E -125 10-10-10 11-11-11 12-12-12 Symbol Min Max Min Max Min Max Unit Internal READ command to first data tAA 12.50 18.00 13.755 18.00 15.00 18.00 ns Internal READ command to first data with read DBI enabled tAA_DBI tAA – tAA – tAA ns ACTIVATE to internal READ or WRITE delay time tRCD 12.50 – 13.755 tRP 12.50 – ACTIVATE-to-PRECHARGE command period tRAS 35 9 × tREFI ACTIVATE-to-ACTIVATE or REFRESH command period tRC PRECHARGE command period READ: nonDBI READ: DBI WRITE (MIN) + 2nCK tRAS – (MIN) + 2nCK + – tRP (MAX) + 2nCK – 15.00 13.755 – 15.00 – ns 35 9 × tREFI 35 9 × tREFI ns – ns Max Unit tRAS + – tRP Symbol Min Max Min Max 1.5 1.9 CL = 9 CL = 11 CWL = 9 1.5 1.9 CL = 10 CL = 12 CWL = 9 tCK4 1.5 1.6 Reserved CWL = 9, 11 tCK4 1.25