IS43LD32320C-25BLI

IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality 1Gb (x16, x32) Mobile LPDDR2 S4 SDRAM JULY 2021 FEATURES DESCRIPTION • Low-voltage Core and I/O Power Supplies VDD2 = 1.14-1.30V, VDDCA/VDDQ = 1.14-1.30V, VDD1 = 1.70-1.95V • High Speed Un-terminated Logic(HSUL_12) I/O Interface • Clock Frequency Range : 10MHz to 533MHz (data rate range : 20Mbps to 1066Mbps per I/O) • Four-bit Pre-fetch DDR Architecture • Multiplexed, double data rate, command/address inputs • Eight internal banks for concurrent operation • Bidirectional/differential data strobe per byte of data (DQS/DQS#) • Programmable Read/Write latencies(RL/WL) and burst lengths(4,8 or 16) • ZQ Calibration • On-chip temperature sensor to control self refresh rate • Partial –array self refresh(PASR) • Deep power-down mode(DPD) • Operation Temperature The IS43/46LD16640C/32320C is 1Gbit CMOS LPDDR2 DRAM. The device is organized as 8 banks of 8Meg words of 16bits or 4Meg words of 32bits. This product uses a double-data-rate architecture to achieve high-speed operation. The double data rate architecture is essentially a 4N prefetch architecture with an interface designed to transfer two data words per clock cycle at the I/O pins. This product offers fully synchronous operations referenced to both rising and falling edges of the clock. The data paths are internally pipelined and 4n bits prefetched to achieve very high bandwidth. Commercial (TC = 0°C to 85°C) Industrial (TC = -40°C to 85°C) Automotive, A1 (TC = -40°C to 85°C) Automotive, A2 (TC = -40°C to 105°C) OPTIONS • Configuration: − 64Mx16 (8M x 16 x 8 banks) − 32Mx32 (4M x 32 x 8 banks) Package: − 134-ball BGA for x16 / x32 ADDRESS TABLE Parameter Row Addresses Column Addresses Bank Addresses Refresh Count 32Mx32 R0-R12 C0-C8 BA0-BA2 4096 64Mx16 R0-R12 C0-C9 BA0-BA2 4096 KEY TIMING PARAMETERS1 Speed Grade -18 -25 -3 Data Rate (Mb/s) 1066 800 667 Write Read tRCD/ Latency Latency tRP2 4 3 2 8 6 5 Typical Typical Typical Note: 1. Other clock frequencies/data rates supported; please refer to AC timing tables. 2. Please contact ISSI for fast tRCD/tRP Copyright © 2021 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its products at any time without notice. ISSI assumes no liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and before placing orders for products. Integrated Silicon Solution, Inc. does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless Integrated Silicon Solution, Inc. receives written assurance to its satisfaction, that: a.) the risk of injury or damage has been minimized; b.) the user assume all such risks; and c.) potential liability of Integrated Silicon Solution, Inc is adequately protected under the circumstances Integrated Silicon Solution, Inc. — www.issi.com 1 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C BALL ASSIGNMENTS AND DESCRIPTIONS 134-ball FBGA (x32), 0.65mm pitch A B C D E F G H J K L M N P R T U 1 2 3 DNU DNU DNU NC NC VDD1 VSS RFU VSS VDD2 ZQ VSSCA CA9 CA8 VDDCA CA6 VDD2 4 5 7 8 10 DNU DNU DQ26 DNU DQ31 VSS VSSQ VDDQ DQ25 VSSQ VDDQ VDDQ DQ30 DQ27 DQS3 DQS3# VSSQ DQ28 DQ24 DM3 DQ15 VDDQ VSSQ CA7 VSSQ DQ11 DQ13 DQ14 DQ12 VDDQ CA5 Vref(CA) DQS1# DQS1 DQ10 DQ9 DQ8 VSSQ VDDCA VSS CK# DM1 VDDQ VSSCA NC CK VSSQ VDDQ VDD2 VSS Vref(DQ) CKE RFU RFU DM0 VDDQ CS# RFU RFU DQS0# DQS0 DQ5 DQ6 DQ7 VSSQ CA4 CA3 CA2 VSSQ DQ4 DQ2 DQ1 DQ3 VDDQ VSSCA VDDCA CA1 DQ19 DQ23 DM2 DQ0 VDDQ VSSQ VSS VDD2 CA0 VDDQ DQ17 DQ20 DQS2 DQS2# VSSQ VDD1 VSS NC VSS VSSQ VDDQ DQ22 VSSQ VDDQ DNU NC NC VDD2 VDD1 DQ16 DQ18 DQ21 DNU DNU DNU DNU DNU 1 2 9 10 4 5 6 7 DQ29 9 VDD1 3 VDD2 6 8 A B C D E F G H J K L M N P R T U DQ CA Power Ground No ball ZQ Clock NC, DNU, RFU Top View (ball down) Integrated Silicon Solution, Inc. — www.issi.com 2 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C BALL ASSIGNMENTS AND DESCRIPTIONS 134-ball FBGA (x16), 0.65mm pitch A B C D E F G H J K L M N P R T U 1 2 3 9 10 DNU DNU DNU DNU DNU NC NC VDD2 VDD1 NC NC NC DNU VDD1 VSS RFU VSS VSSQ VDDQ NC VSSQ VDDQ VSS VDD2 ZQ VDDQ NC NC NC NC VSSQ VSSCA CA9 CA8 NC NC NC DQ15 VDDQ VSSQ VDDCA CA6 CA7 VSSQ DQ11 DQ13 DQ14 DQ12 VDDQ VDD2 CA5 Vref(CA) DQS1# DQS1 DQ10 DQ9 DQ8 VSSQ VDDCA VSS CK# DM1 VDDQ VSSCA NC CK VSSQ VDDQ CKE RFU RFU DM0 VDDQ CS# RFU RFU DQS0# DQS0 DQ5 DQ6 DQ7 VSSQ CA4 CA3 CA2 VSSQ DQ4 DQ2 DQ1 DQ3 VDDQ VSSCA VDDCA CA1 NC NC NC DQ0 VDDQ VSSQ VSS VDD2 CA0 VDDQ NC NC NC NC VSSQ VDD1 VSS NC VSS VSSQ VDDQ NC VSSQ VDDQ DNU NC NC VDD2 VDD1 NC NC NC DNU DNU DNU DNU DNU 1 2 9 10 3 4 4 5 5 6 6 7 VDD2 7 8 VSS 8 Vref(DQ) A B C D E F G H J K L M N P R T U DQ CA Power Ground No ball ZQ Clock NC, DNU, RFU Top View (ball down) Integrated Silicon Solution, Inc. — www.issi.com 3 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality INPUT/OUTPUT FUNCTIONAL DESCRIPTION Pad Definition and Description Name Type Description CK, CK# Input Clock: CK and CK# are differential clock inputs. All Double Data Rate (DDR) CA inputs are sampled on both positive and negative edge of CK. Single Data Rate (SDR) inputs, CS# and CKE, are sampled at the positive Clock edge. Clock is defined as the differential pair, CK and CK#. The positive Clock edge is defined by the crosspoint of a rising CK and a falling CK#. The negative Clock edge is defined by the crosspoint of a falling CK and a rising CK#. CKE Input Clock Enable: CKE HIGH activates and CKE LOW deactivates internal clock signals and therefore device input buffers and output drivers. Power savings modes are entered and exited through CKE transitions. CKE is considered part of the command code. See Command Truth Table for command code descriptions. CKE is sampled at the positive Clock edge. CS# Input Chip Select: CS# is considered part of the command code. See Command Truth Table for command code descriptions. CS# is sampled at the positive Clock edge. CA0 - CA9 Input DDR Command/Address Inputs: Uni-directional command/address bus inputs. CA is considered part of the command code. See Command Truth Table for command code descriptions. I/O Data Inputs/Output: Bi-directional data bus I/O Data Strobe (Bi-directional, Differential): The data strobe is bi-directional (used for read and write data) and differential (DQS and DQS#). It is output with read data and input with write data. DQS is edge-aligned to read data and centered with write data. DQ0 - DQ15 (x16) DQ0 - DQ31 (x32) DQS0, DQS0#, DQS1, DQS1# (x16) DQS0 DQS3, DQS0# DQS3# (x32) For x16, DQS0 and DQS0# correspond to the data on DQ0 - DQ7; DQS1 and DQS1# to the data on DQ8 - DQ15. For x32 DQS0 and DQS0# correspond to the data on DQ0 - DQ7, DQS1 and DQS1# to the data on DQ8 - DQ15, DQS2 and DQS2# to the data on DQ16 - DQ23, DQS3 and DQS3# to the data on DQ24 - DQ31. Input DM0-DM1 (x16) DM0 - DM3 (x32) Input Data Mask: For LPDDR2 devices that do not support the DNV feature, DM is the input mask signal for write data. Input data is masked when DM is sampled HIGH coincident with that input data during a Write access. DM is sampled on both edges of DQS. Although DM is for input only, the DM loading shall match the DQ and DQS (or DQS#). DM0 is the input data mask signal for the data on DQ0-7. For x16 and x32 devices, DM1 is the input data mask signal for the data on DQ8-15. For x32 devices, DM2 is the input data mask signal for the data on DQ16-23 and DM3 is the input data mask signal for the data on DQ24-31. Integrated Silicon Solution, Inc. — www.issi.com 4 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Name Type Description VDD1 Supply Core Power Supply 1 VDD2 Supply Core Power Supply 2 VDDCA Supply Input Receiver Power Supply: input buffers. VDDQ Supply I/O Power Supply: Power supply for Data input/output buffers. VREF(CA) Supply Reference Voltage for CA Command and Control Input Receiver: for all CA0-9, CKE, CS#, CK, and CK# input buffers. VREF(DQ) Supply Reference Voltage for DQ Input Receiver: VSS Supply Ground VSSCA Supply Ground for Input Receivers VSSQ Supply I/O Ground ZQ I/O Power supply for CA0-9, CKE, CS#, CK, and CK# Reference voltage Reference voltage for all Data input buffers. Reference Pin for Output Drive Strength Calibration NOTE 1 Data includes DQ and DM. Integrated Silicon Solution, Inc. — www.issi.com 5 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C FUNCTIONAL BLOCK DIAGRAM CS# CA0 CA1 CA2 CA3 CA4 CA5 CA6 CA7 CA8 CA9 Control logic Command / Address Multiplex and Decode CKE CK CK# Mode registers x Refresh x counter Rowaddress MUX Bank 3 Bank 2 Bank 1 Bank 0 rowaddress latch and decoder Bank 3 Bank 2 Bank 1 Bank 0 COL0 n Memory array 4n Read latch n MUX n n Sense amplifier 2 I/O gating DM mask logic Bank control logic Columnaddress counter/ latch y-1 Column decoder DRVRS DQ0–DQn-1 DQS generator DQS, DQS# Input registers 4 4 4n 2 n DATA WRITE FIFO and 4n drivers CK, CK# CK out CK in 1 8 Mask 4n Data 4 4 4 4 4 4 n n n n n n n n DQS, DQS# 4 RCVRS n DM COL0 Integrated Silicon Solution, Inc. — www.issi.com 6 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C SIMPLIFIED STATE DIAGRAM Power applied Deep power-down DPDX Power-on RE Automatic sequence SET Resetting MR reading Command sequence MRR Self refreshing Resetting DPD MRR SR EF REF Idle 1 Refreshing X M PD RW Idle MR reading X T SE RE X PD Resetting power-down SR EF PD PD Idle power-down MR writing ACT Active power-down Active MR reading PD X PD R MR Active BST PR BST RD WR RD Reading A WR RD Writing A WR PR, PRA WRA RDA Writing with auto precharge Reading with auto precharge Precharging Abbreviation ACT RD(A) WR(A) PR(A) MRW MRR Function Active Read (w/ Autoprecharge) Write (w/ Autoprecharge) Precharge (All) Mode Register Write Mode Register Read Abbreviation PD PDX DPD DPDX BST RESET Function Enter Power Down Exit Power Down Enter Deep Power Down Abbreviation REF SREF Function Refresh Enter self refresh SREFX Exit self refresh Exit Deep Power Down Burst Terminate Reset is achieved through MRW command Note: For LPDDR2-S4 SDRAM in the idle state, all banks are precharged. Integrated Silicon Solution, Inc. — www.issi.com 7 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality FUNCTIONAL DESCRIPTION LPDDR2-S4 is a high-speed SDRAM device internally configured as an 8-Bank memory. This device contains 1,073,741,824 bits (1 Gigabit) All LPDDR2 devices use a double data rate archiecture on the Command/Address (CA) bus to reduce the number of input pins in the system. The 10-bit CA bus contains command, address, and Bank/Row Buffer information. Each command uses one clock cycle, during which command information is transferred on both the positive and negative edge of the clock. This LPDDR2-S4 device also uses a double data rate architecture on the DQ pins to achieve high speed operation. The double data rate architecture is essentially a 4n prefetch architecture with an interface designed to transfer two data bits per DQ every clock cycle at the I/O pins. A single read or write access for the memory device effectively consists of a single 4n-bit wide, one clock cycle data transfer at the internal SDRAM core and four corresponding nbit wide, one-half-clock-cycle data transfers at the I/O pins. Read and write accesses to the LPDDR2 are burst oriented; accesses start at a selected location and continue for a programmed number of locations in a programmed sequence. Accesses begin with the registration of an Activate command, which is then followed by a Read or Write command. The address and BA bits registered coincident with the Activate command are used to select the row and the Bank to be accessed. The address bits registered coincident with the Read or Write command are used to select the Bank and the starting column location for the burst access. Prior to normal operation, the LPDDR2 must be initialized. The following section provides detailed information covering device initialization, register definition, command description and device operation. Integrated Silicon Solution, Inc. — www.issi.com 8 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality POWER-UP AND INITIALIZATION DDR2 SDRAMs must be powered up and initialized in a predefined manner. Operational procedures other than those specified may result in undefined operation. The following sequence is required for Power-up and Initialization. 1. Voltage ramp up sequence is required : A. While applying power, attempt to maintain CKE below 0.2 x VDDCA and all other inputs must be between VILmin and VIHmax. The device outputs remain at High-Z while CKE is held LOW. The voltage ramp time tINIT0 ( Tb-Ta) must be no greater than 20 ms from Tb which is point for all supply and reference voltage are within their defined operating ranges , to Ta which is point for any power supply first reaches 300mV. B. The following conditions apply for voltage ramp after Ta is reached, − VDD1 must be greater than VDD2-200mV AND − VDD1 and VDD2 must be greater than VDDCA-200mV AND − VDD1 and VDD2 must be greater than VDDQ-200mV AND − VREF must always be less than all other supply voltages − The voltage difference between any of VSS, VSSQ, and VSSCA pins must not exceed 100mV 2. Start clock and maintain stable condition. Beginning at Tb, CKE must remain LOW for at least tINIT1 = 100 ns, after which CKE can be asserted HIGH. The clock must be stable at least tINIT2 = 5 × tCK prior to the first CKE LOW-to-HIGH transition (Tc). CKE, CS#, and CA inputs must observe setup and hold requirements (tIS, tIH) with respect to the first rising clock edge (and to subsequent falling and rising edges). Once the ramping of the supply voltages is complete ( Tb), CKE must be maintained LOW. DQ, DM, DQS and DQS# voltage levels must be between VSSQ and VDDQ during voltage ramp to avoid latchup. CK, CK#, CS#, and CA input levels must be between VSSCA and VDDCA during voltage ramp to avoid latch-up If any Mode Register Read ( MRRs ) are issued, the clock period must be within the range defined for tCKb (18ns to 100ns). Mode Register Write (MRWs) can be issued at normal clock frequencies as long as all AC timings are met. Some AC parameters could have relaxed timings before the system is appropriately configured. While keeping CKE HIGH, NOP commands must be issued for at least tINIT3 = 200μs (Td). 3. RESET Command After tINIT3 is satisfied, the MRW RESET command must be issued (Td). An optional PRECHARGE ALL command can be issued prior to the MRW RESET command. Wait at least tINIT4 while keeping CKE asserted and issuing NOP commands 4. Mode Register Reads and Device Auto Initialization (DAI) Polling: After tINIT4 is satisfied (Te), only MRR commands and power-down entry/exit commands are supported. After Te, CKE can go LOW in alignment with power-down entry and exit specifications. Use the MRR command to poll the DAI bit and report when device auto initialization is complete; otherwise, the controller must wait a minimum of tINIT5, or until the DAI bit is set before proceeding. As the memory output buffers are not properly configured by Te, some AC parameters must have relaxed timings before the system is appropriately configured. After the DAI bit (MR0, DAI) is set to zero by the memory device (DAI complete), the device is in the idle state (Tf ). DAI status can be determined by issuing the MRR command to MR0. The device sets the DAI bit no later than tINIT5 after the RESET command. The controller must wait at least tINIT5 or until the DAI bit is set before proceeding Integrated Silicon Solution, Inc. — www.issi.com 9 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C 5. ZQ Calibration After tINIT5 (Tf ), the MRR initialization calibration (ZQ_CAL) command can be issued to the memory (MR10). This command is used to calibrate output impedance over process, voltage, and temperature. In systems where more than one LPDDR2 device exists on the same bus, the controller must not overlap MRR ZQ_CAL commands. The device is ready for normal operation after tZQINIT. 6. Normal Operation After tZQINIT (Tg), MRW commands must be used to properly configure the memory . Specifically, MR1, MR2, and MR3 must be set to configure the memory for the target frequency and memory configuration After the initialization sequence is complete, the device is ready for any valid command. After Tg, the clock frequency can be changed using the procedure described in Input Clock Frequency Changes and Clock Stop Events‖. INITIALIZATION TIMING Symbol Parameter tINIT0 Value Maximum Power Ramp Time Unit min max - 20 ms tINIT1 Minimum CKE low time after completion of power ramp 100 - ns tINIT2 Minimum stable clock before first CKE high 5 - tCK tINIT3 Minimum idle time after first CKE assertion 200 - us tINIT4 Minimum idle time after Reset command, this time will be about 2 x tRFCab + tRPab 1 - us tINIT5 Maximum duration of Device Auto-Initialization - 10 us tCKb Clock cycle time during boot 18 100 ns ZQ initial calibration 1 - us tZQINIT Figure - Power Ramp and Initialization Sequence Ta Tb t INIT2 Tc Td Te Tf Tg CK/CK# t INIT0 Supplies t INIT1 t INIT3 CKE t ISCKE CA t INIT4 RESET t INIT5 MRR t ZQINIT MRW ZQ_CAL Valid R TT DQ Initialization After RESET (without voltage ramp): If the RESET command is issued before or after the power-up initialization sequence, the re-initialization procedure must begin at Td Integrated Silicon Solution, Inc. — www.issi.com 10 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Power-Off Sequence Use the following sequence to power off the device. Unless specified otherwise, this procedure is mandatory and applies to S4 devices. While powering off, CKE must be held LOW (≤ 0.2 × VDDCA); all other inputs must be between VILmin and VIHmax. The device outputs remain at High-Z while CKE is held LOW. DQ, DM, DQS, and DQS# voltage levels must be between VSSQ and VDDQ during the power-off sequence to avoid latch-up. CK, CK#, CS#, and CA input levels must be between VSSCA and VDDCA during the power-off sequence to avoid latch-up. Tx is the point where any power supply drops below the minimum value specified in the DC operating condition table. Tz is the point where all power supplies are below 300mV. After Tz, the device is powered off Required Power Supply Conditions Between Tx and Tz: • VDD1 must be greater than VDD2 - 200mV • VDD1 must be greater than VDDCA - 200mV • VDD1 must be greater than VDDQ - 200mV • VREF must always be less than all other supply voltages The voltage difference between VSS, VSSQ, and VSSCA must not exceed 100mV. For supply and reference voltage operating conditions, see Recommended DC Operating Conditions table. Uncontrolled Power-Off Sequence When an uncontrolled power-off occurs, the following conditions must be met: 1. At Tx, when the power supply drops below the minimum values specified, all power supplies must be turned off and all power-supply current capacity must be at zero, except for any static charge remaining in the system. 2. After Tz , the device must power off. The time between Tx and Tz must not exceed 20ms. During this period, the relative voltage between power supplies is uncontrolled. VDD1 and VDD2 must decrease with a slope lower than 0.5 V/μs between Tx and Tz. An uncontrolled power-off sequence can occur a maximum of 400 times over the life of the device Mode Register Definition LPDDR2 devices contain a set of mode registers used for programming device operating parameters, reading device information and status, and for initiating special operations such as DQ calibration, ZQ calibration, and device reset. Integrated Silicon Solution, Inc. — www.issi.com 11 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Mode Register Assignment The MRR command is used to read from a register. The MRW command is used to write to a register. Mode Register Assignment MR# MA Function Access OP7 OP6 0 00H Device Info. R (RFU) 1 01H Device Feature1 W nWR (for AP) 2 02H Device Feature2 W (RFU) RL & WL 3 03H I/O Config-1 W (RFU) DS 4 04H Refresh Rate R 5 05H Basic Config-1 R LPDDR2 Manufacturer ID 6 06H Basic Config-2 R Revision ID1 7 07H Basic Config-3 R Revision ID2 8 08H Basic Config-4 R 9 09H Test Mode W Vendor-Specific Test Mode 10 0AH IO Calibration W Calibration Code 11~15 0BH~0FH (reserved) TUF OP5 OP4 OP3 RZQI WC OP2 OP1 OP0 (RFU) DI DAI BT BL (RFU) I/O width Refresh Rate Density Type (RFU) Mode Register Assignment MR# MA Function Access OP7 OP6 OP5 OP4 OP3 16 10H PASR_BANK W Bank Mask 17 11H PASR_Seg W Segment Mask 18-19 12H-13H (Reserved) OP2 OP1 OP0 (RFU) Integrated Silicon Solution, Inc. — www.issi.com 12 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Mode Register Assignment MR# MA 20-31 18H-1FH Function Access OP7 OP6 OP5 OP4 OP3 OP2 OP1 OP0 Reserved Mode Register Assignment (Reset Command & RFU part) MR# MA Function Access OP7 OP6 OP5 OP4 OP3 OP2 OP1 32 20H DQ calibration pattern A R See “Data Calibration Pattern Description” 33-39 21H-27H (Do Not Use) 40 28H DQ calibration pattern B R See “Data Calibration Pattern Description” 41-47 29H-2FH (Do Not Use) 48-62 30H-3EH (Reserved) 63 3FH Reset 64-126 40H-7EH (Reserved) 127 7FH (Do Not Use) 128-190 80H-BEH (Reserved for Vendor Use) 191 BFH (Do Not Use) 192-254 C0H-FEH (Reserved for Vendor Use) 255 FFH (Do Not Use) OP0 (RFU) W X (RFU) (RFU) (RFU) Notes: 1. RFU bits shall be set to ‘0’ during Mode Register writes. 2.RFU bits shall be read as ‘0’ during Mode Register reads. 3.All Mode Registers that are specified as RFU or write-only shall return undefined data when read and DQS shall be toggled. 4.All Mode Registers that are specified as RFU shall not be written. 5.See Vendor Device Datasheets for details on Vendor Specific Mode Registers. 6.Writes to read-only registers shall have no impact on the functionality of the device. MR0_Device Information (MA = 00H): OP7 OP6 (RFU) OP OP5 OP4 OP3 RZQI OP2 OP1 OP0 (RFU) DI DAI RZQI Read-only 00B: RZQ self test not supported 01B: ZQ pin might be connected to VDDCA or left floating 10B: ZQ pin might be shorted to ground 11B: ZQ pin self test compelte; no error condition detected OP1 DI (Device Information) Read-only 0 B: SDRAM 1 B: Do Not Use OP0 DAI (Device Auto-Initialization Status) Read-only 0 B: DAI complete 1 B: DAI still in progress Notes: 1. If RZQI is supported, it will be set upon completion of the MRW ZQ initialization calibration. 2. If ZQ is connected to VDDCA, to set default calibration, OP[4:3] must be set to 01. If ZQ is not connected to VDDCA, either OP[4:3] = 01 or OP[4:3] = 10 could indicate a ZQ-pin assembly error. It is recommended that the assembly error be corrected. 3. In the case of a possible assembly error (either OP[4:3] = 01 or OP[4:3] = 10, as defined above), the device will default to factory trim settings for RON and ignore ZQ calibration commands. In either case, the system might not function as intended. 4. If a ZQ self test returns a value of 11b, this indicates that the device has detected a resistor connection to the ZQ pin. Note that this result cannot be used to validate the ZQ resistor value, nor does it indicate that the ZQ resistor tolerance meets the specified limits (240 ohm ±1%). Integrated Silicon Solution, Inc. — www.issi.com 13 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C MR1_Devcie Feature 1 (MA = 01H): OP7 OP6 OP5 nWR (for AP) OP4 OP3 WC BT OP2 OP1 OP0 BL 010B: BL4 (default) OP BL (Burst Length) 011B: BL8 Write-only 100B: BL16 All others: reserved *1 OP3 BT (Burst Type) Write-only OP4 WC (Wrap) Write-only 0B: Sequential (default) 1B: Interleaved 0B: Wrap (default) 1B: No wrap (allowed for SDRAM BL4 only) 001B: nWR=3 (default) 010B: nWR=4 011B: nWR=5 OP *2 nWR Write-only 100B: nWR=6 101B: nWR=7 110B: nWR=8 All others: reserved Notes: 1. BL16, interleaved is not an official combination to be supported. 2. Programmed value in nWR register is the number of clock cycles which determines when to start internal precharge operation for a write burst with AP enabled. It is determined by RU(tWR/tCK) Burst Sequence by BL, BT, and WC C3 C2 C1 C0 x x 0B 0B x x 1B 0B x x x 0B WC BT BL wrap any nw any 4 Burst Cycle Number and Burst Address Sequence 1 2 3 4 0 1 2 3 2 3 0 1 y 5 6 7 8 9 10 11 12 13 14 15 16 y+1 y+2 y+3 Integrated Silicon Solution, Inc. — www.issi.com 14 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C C1 C0 WC Burst Cycle Number and Burst Address Sequence C3 C2 BT BL x 0B 0B 0B x 0B 1B 0B x 1B 0B 0B x 1B 1B 0B x 0B 0B 0B x 0B 1B 0B x 1B 0B 0B x 1B 1B 0B x x x 0B 0B 0B 0B 0B 0 1 2 3 4 5 6 7 8 0B 0B 1B 0B 2 3 4 5 6 7 8 9 0B 1B 0B 0B 4 5 6 7 8 9 A 0B 1B 1B 0B 6 7 8 9 A B 1B 0B 0B 0B wrap 8 9 A B C 1B 0B 1B 0B A B C D 1B 1B 0B 0B C D E 1B 1B 1B 0B E F 0 x x x 0B int illegal (not allowed) x x x 0B nw any illegal (not allowed) seq 8 wrap int 1 2 3 4 5 6 7 8 0 1 2 3 4 5 6 7 2 3 4 5 6 7 0 1 4 5 6 7 0 1 2 3 6 7 0 1 2 3 4 5 0 1 2 3 4 5 6 7 2 3 0 1 6 7 4 5 4 5 6 7 0 1 2 3 6 7 4 5 2 3 0 1 11 12 13 14 15 16 9 A B C D E F A B C D E F 0 1 B C D E F 0 1 2 3 C D E F 0 1 2 3 4 5 D E F 0 1 2 3 4 5 6 7 E F 0 1 2 3 4 5 6 7 8 9 F 0 1 2 3 4 5 6 7 8 9 A B 1 2 3 4 5 6 7 8 9 A B C D nw any 9 10 illegal (not allowed) seq 16 Notes: 1. C0 input is not present on CA bus. It is implied zero. 2. For BL=4, the burst address represents C1~C0. 3. For BL=8, the burst address represents C2~C0. 4. For BL=16, the burst address represents C3~C0. 5. For no-wrap, BL4, the burst must not cross the page boundary or the sub-page boundary.The variabley can start at any address with C0 equal to 0, but must not start at any address shown below Non-Wrap Restrictions Width 64Mb 128Mb/256Mb 512Mb/1Gb/2Gb 4Gb/8Gb Cannot cross full page boundary X16 FE, FF, 00, 01 1FE, 1FF, 000, 001 3FE, 3FF, 000, 001 7FE, 7FF, 000, 001 X32 7E, 7F, 00, 01 FE, FF, 00, 01 1FE, 1FF, 000, 001 3FE, 3FF, 000, 001 Cannot cross sub-page boundary X16 7E, 7F, 80, 81 0FE, 0FF, 100, 101 1FE, 1FF, 200, 201 3FE, 3FF, 400, 401 X32 none none None none Note: Non-wrap BL=4 data orders shown are prohibited. . Integrated Silicon Solution, Inc. — www.issi.com 15 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C MR2_Device Feature 2 (MA = 02H): OP7 OP6 OP5 OP4 OP3 (RFU) OP2 OP1 OP0 RL & WL 0001B: RL3 / WL1 (default) 0010B: RL4 / WL2 0011B: RL5 / WL2 RL & WL (Read Latency & Write OP Write-only Latency) 0100B: RL6 / WL3 0101B: RL7 / WL4 0110B: RL8 / WL4 All others: reserved MR3_I/O Configuration 1 (MA = 03H): OP7 OP6 OP5 OP4 OP3 OP2 (RFU) OP1 OP0 DS 0000B: reserved 0001B: 34.3 ohm typical 0010B: 40.0 ohm typical (default) OP DS (Drive Strength) Write-only 0011B: 48.0 ohm typical 0100B: 60.0 ohm typical 0101B: reserved 0110B: 80.0 ohm typical 0111B: 120.0 ohm typical All others: reserved MR4_Device Temperature (MA = 04H): OP7 OP6 TUF OP5 OP4 OP3 (RFU) OP2 OP1 OP0 SDRAM Refresh Rate 000B: 4 x tREFI, SDRAM Low Temp. operating limit exceeded 001B: 4 × tREFI, 4 × tREFIpb, 4 × tREFW OP SDRAM Refresh Rate Read-only 010B: 2 × tREFI, 2 × tREFIpb, 2 × tREFW , 011B: 1 × tREFI, 1 × tREFIpb, 1 × tREFW ( tCK Burst Read: RL=5, BL=4, tDQSCK > tCK Integrated Silicon Solution, Inc. — www.issi.com 34 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Burst READ – RL = 3, BL = 8, tDQSCK < tCK t t Burst Read: RL=3, BL=8, DQSCK < CK Integrated Silicon Solution, Inc. — www.issi.com 35 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality tDQSCKDL Timing Notes: 1. tDQSCKDL = (tDQSCKn - tDQSCKm). 2. tDQSCKDL (MAX) is defined as the maximum of ABS (tDQSCKn - tDQSCKm) for any (tDQSCKn, tDQSCKm) pair within any 32ms rolling window. Integrated Silicon Solution, Inc. — www.issi.com 36 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality tDQSCKDM Timing t DQSCKDM timing Notes: 1. tDQSCKDM = (tDQSCKn - tDQSCKm). 2. tDQSCKDM (MAX) is defined as the maximum of ABS (tDQSCKn - tDQSCKm) for any (tDQSCKn, tDQSCKm) pair within any 1.6μs rolling window. Integrated Silicon Solution, Inc. — www.issi.com 37 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C DQSCKDS timing tDQSCKDS t ® Long-term Support World Class Quality Timing Notes: 1. tDQSCKDS = (tDQSCKn - tDQSCKm). 2. tDQSCKDS (MAX) is defined as the maximum of ABS (tDQSCKn - tDQSCKm) for any (tDQSCKn, tDQSCKm) pair for READs within a consecutive burst, within any 160ns rolling window. Integrated Silicon Solution, Inc. — www.issi.com 38 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Burst READ Followed by Burst WRITE – RL = 3, WL = 1, BL = 4 The minimum time from the burst READ command to the burst WRITE command is defined by the read latency (RL) and the burst length (BL). Minimum READ-to-WRITE latency is RL + RU(tDQSCK(MAX)/tCK) + BL/2 + 1 - WL clock cycles. Note that if a READ burst is truncated with a burst TERMINATE (BST) command, the effective burst length of the truncated READ burst should be used for BL when calculating the minimum READ-to-WRITE delay. Seamless Burst READ – RL = 3, BL = 4, tCCD = 2 A seamless burst READ operation is supported by enabling a READ command at every other clock cycle for BL = 4 operation, every fourth clock cycle for BL = 8 operation, and every eighth clock cycle for BL = 16 operation. This operation is supported as long as the banks are activated, whether the accesses read the same or different banks. Integrated Silicon Solution, Inc. — www.issi.com 39 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality READs Interrupted by a READ For LP-DDR2-S4 devices, burst READ can be interrupted by another READ with a 4-bit burst boundary, provided that tCCD is met. A burst READ can be interrupted by other READs on any subsequent clock, provided that tCCD is met. READ Burst Interrupt Example – RL = 3, BL = 8, tCCD = 2 Note: READs can only be interrupted by other READs or the BST command. Integrated Silicon Solution, Inc. — www.issi.com 40 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Burst WRITE The burst WRITE command is initiated with CS# LOW, CA0 HIGH, CA1 LOW, and CA2 LOW at the rising edge of the clock. The command address bus inputs, CA5r–CA6r and CA1f–CA9f, determine the starting column address for the burst. Write latency (WL) is defined from the rising edge of the clock on which the WRITE command is issued to the rising edge of the clock from which the tDQSS delay is measured. The first valid data must be driven WL × tCK + tDQSS from the rising edge of the clock from which the WRITE command is issued. The data strobe signal (DQS) must be driven LOW tWPRE prior to data input. The burst cycle data bits must be applied to the DQ pins tDS prior to the associated edge of the DQS and held valid until tDH after that edge. Burst data is sampled on successive edges of the DQS until the 4-, 8-, or 16-bit burst length is completed. After a burst WRITE operation, tWR must be satisfied before a PRECHARGE command to the same bank can be issued. Pin input timings are measured relative to the crosspoint of DQS and its complement, DQS#. Data Input (WRITE) Timing Data input (Write) timing Integrated Silicon Solution, Inc. — www.issi.com 41 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Burst WRITE – WL = 1, BL = 4 NT6TL64M32AQ Burst Burst WRITE Followed by Burst READ – write: RL =WL=1, 3, WLBL=4 = 1, BL = 4 Burst write followed by burst read: RL=3, WL=1, BL=4 Notes: 1. The minimum number of clock cycles from the burst WRITE command to the burst READ command for any bank is [WL + 1 + BL/2 + RU(tWTR/tCK)]. 2. tWTR starts at the rising edge of the clock after the last valid input data. 3. If a WRITE burst is truncated with a BST command, the effective burst length of the truncated WRITE burst should be used as BL to calculate the minimum WRITE-to-READ delay. Integrated Silicon Solution, Inc. — www.issi.com 42 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Seamless Burst WRITE – WL = 1, BL = 4, tCCD = 2 Note: The seamless burst WRITE operation is supported by enabling a WRITE command every other clock for BL = 4 operation, every four clocks for BL = 8 operation, or every eight clocks for BL = 16 operation. This operation is supported for any activated bank. WRITEs Interrupted by a WRITE For LPDDR2-S4 devices, a burst WRITE can only be interrupted by another WRITE with a 4-bit burst boundary, provided that tCCD (MIN) is met. A WRITE burst interrupt can occur on any clock after the initial WRITE command, provided that tCCD (MIN) is met. WRITE Burst Interrupt Timing – WL = 1, BL = 8, tCCD = 2 Notes: 1. WRITEs can only be interrupted by other WRITEs or the BST command. 2. The effective burst length of the first WRITE equals two times the number of clock cycles between the first WRITE and the interrupting WRITE Integrated Silicon Solution, Inc. — www.issi.com 43 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality BURST TERMINATE (BST) The BURST TERMINATE (BST) command is initiated with CS# LOW, CA0 HIGH, CA1 HIGH, CA2 LOW, and CA3 LOW at the rising edge of the clock. A BST command can only be issued to terminate an active READ or WRITE burst. Therefore, a BST command can only be issued up to and including BL/2 - 1 clock cycles after a READ or WRITE command. The effective burst length of a READ or WRITE command truncated by a BST command is as follows: • Effective burst length = 2 × (number of clock cycles from the READ or WRITE command to the BST command). • If a READ or WRITE burst is truncated with a BST command, the effective burst length of the truncated burst should be used for BL when calculating the minimum READ to-WRITE or WRITEto-READ delay. • The BST command only affects the most recent READ or WRITE command. The BST command truncates an ongoing READ burst RL × tCK + tDQSCK + tDQSQ after the rising edge of the clock where the BST command is issued. The BST command truncates an ongoing WRITE burst WL × tCK + tDQSS after the rising edge of the clock where the BST command is issued. • The 4-bit prefetch architecture enables BST command assertion on even clock cycles following a WRITE or READ command. The effective burst length of a READ or WRITE command truncated by a BST command is thus an integer multiple of four. Burst WRITE Truncated by BST – WL = 1, BL = 16 Burst Write truncated by BST: WL=1, BL=16 Notes: 1. The BST command truncates an ongoing WRITE burst WL × tCK + tDQSS after the rising edge of the clock where the BST command is issued. 2. BST can only be issued an even number of clock cycles after the WRITE command. 3. Additional BST commands are not supported after T4 and must not be issued until after the next READ or WRITE command. Integrated Silicon Solution, Inc. — www.issi.com 44 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Burst READ Truncated by BST – RL = 3, BL = 16 Notes: 1. The BST command truncates an ongoing READ burst (RL × tCK + tDQSCK + tDQSQ) after the rising edge of the clock where the BST command is issued. 2. BST can only be issued an even number of clock cycles after the READ command. 3. Additional BST commands are not supported after T4 and must not be issued until after the next READ or WRITE command Write Data Mask On LPDDR2 devices, one write data mask (DM) pin for each data byte (DQ) is supported, consistent with the implementation on LPDDR SDRAM. Each DM can mask its respective DQ for any given cycle of the burst. Data mask timings match data bit timing, but are inputs only. Internal data mask loading is identical to data bit loading to ensure matched system timing. Data Mask Timing Data Mask Timing Integrated Silicon Solution, Inc. — www.issi.com 45 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Write Data Mask – Second Data Bit Masked Integrated Silicon Solution, Inc. — www.issi.com 46 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C PRECHARGE The PRECHARGE command is used to precharge or close a bank that has been activated. The PRECHARGE command is initiated with CS# LOW, CA0 HIGH, CA1 HIGH, CA2 LOW, and CA3 HIGH at the rising edge of the clock. The PRECHARGE command can be used to precharge each bank independently or all banks simultaneously. This is an 8-bank device, such that the AB flag and the bank address bits BA0, BA1, and BA2 are used to determine which bank(s) to precharge. The precharged bank(s) will be available for subsequent row access tRPab after an all bank PRECHARGE command is issued, or tRPpb after a single-bank PRECHARGE command is issued. In order to ensure that 8-bank devices can meet the instantaneous current demand required to operate, the row precharge time (tRP) for an all bank PRECHARGE in 8-bank devices (tRPab) will be longer than the row precharge time for a single-bank PRECHARGE (tRPpb). Bank Selection for PRECHARGE by Address Bits AB (CA4r) BA2 (CA9r) BA1 (CA8r) BA0 (CA7r) Precharged Bank(s) 8-bank device 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 1 Don't care 0 0 1 1 0 0 1 1 Don't care 0 1 0 1 0 1 0 1 Don't care Bank 0 only Bank 1 only Bank 2 only Bank 3 only Bank 4 only Bank 5 only Bank 6 only Bank 7 only All Banks Bank selection for Precharge by address bits Integrated Silicon Solution, Inc. — www.issi.com 47 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C READ Burst operation Followed by PRECHARGE For the earliest possible precharge, the PRECHARGE command can be issued BL/2 clock cycles after a READ command. A new bank ACTIVATE command can be issued to the same bank after the row precharge time (tRP) has elapsed. A PRECHARGE command cannot be issued until after tRAS is satisfied. The minimum READ-to-PRECHARGE time (tRTP) must also satisfy a minimum analog time from the rising clock edge that initiates the last 4-bit prefetch of a READ command. tRTP begins BL/2 2 clock cycles after the READ command. If the burst is truncated by a BST command, the effective BL value is used to calculate when tRTP begins. READ Burst Followed by PRECHARGE – RL = 3, BL = 8, RU(tRTP(MIN)/tCK) = 2 t t Burst Read followed by Precharge: RL=3, BL=8, RU( RTP(min)/ CK)=2 Integrated Silicon Solution, Inc. — www.issi.com 48 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality READ Burst Followed by PRECHARGE – RL = 3, BL = 4, RU(tRTP(MIN)/tCK) = 3 Burst Read followed by Precharge: RL=3, BL=4, RU( tRTP(min)/tCK) = 3 Integrated Silicon Solution, Inc. — www.issi.com 49 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C WRITE Burst operation Followed by PRECHARGE For WRITE cycles, a WRITE recovery time ( tWR) must be provided before a PRECHARGE command can be issued. This delay is referenced from the last valid burst input data to the completion of the burst WRITE. The PRECHARGE command must not be issued prior to the tWR delay. These devices write data to the array in prefetch quadruples (prefetch = 4). An internal WRITE operation can only begin after a prefetch group has been completely latched. The minimum WRITE-to-PRECHARGE time for commands to the same bank is WL + BL/2 + 1 + RU(tWR/tCK) clock cycles. For untruncated bursts, BL is the value set in the mode register. For truncated bursts, BL is the effective burst length. WRITE Burst Followed by PRECHARGE – WL = 1, BL = 4 Burst Write followed by Precharge: WL=1, BL=4 Integrated Silicon Solution, Inc. — www.issi.com 50 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Auto Precharge Before a new row can be opened in an active bank, the active bank must be precharged using either the PRECHARGE command or the auto precharge function. When a READ or WRITE command is issued to the device, the auto precharge bit (AP) can be set to enable the active bank to automatically begin precharge at the earliest possible moment during the burst READ or WRITE cycle. If AP is LOW when the READ or WRITE command is issued, then normal READ or WRITE burst operation is executed and the bank remains active at the completion of the burst. If AP is HIGH when the READ or WRITE command is issued, the auto precharge function is engaged. This feature enables the PRECHARGE operation to be partially or completely hidden during burst READ cycles (dependent upon READ or WRITE latency), thus improving system performance for random data access. READ Burst with Auto Precharge If AP (CA0f) is HIGH when a READ command is issued, the READ with auto precharge function is engaged. These devices start an auto precharge on the rising edge of the clock BL/2 or BL/2 - 2 + RU(tRTP/ tCK) clock cycles later than the READ with auto precharge command, whichever is greater. For auto precharge calculations see following table. Integrated Silicon Solution, Inc. — www.issi.com 51 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C LPDDR2-S4: PRECHARGE and Auto Precharge Clarification LPDDR2-S4: Precharge & Auto Precharge clarification From Command To Command Precharge (to same Bank as Read) Precharge All Precharge (to same Bank as Read) BST (for Reads) Precharge All Precharge (to same Bank as Read w/AP) Precharge All Read Minimum Delay between "From Command" to Note Unit "To Command" s BL/2 + max(2, RU(tRTP/tCK)) - 2 BL/2 + max(2, RU(tRTP/tCK)) - 2 1 1 BL/2 + max(2, RU(tRTP/tCK)) - 2 BL/2 + max(2, RU(tRTP/tCK)) - 2 BL/2 + max(2, RU( RTP/ CK)) - 2 + Activate (to same Bank as Read w/AP) RU(tRP /tCK) Read w/AP Write or Write w/AP (same bank) illegal t Write or Write w/AP (different bank) RL + BL/2 + RU( DQSCKmax/tCK) - WL + 1 Read or Read w/AP (same bank) illegal Read or Read w/AP (different bank) BL/2 Precharge (to same Bank as Write) WL + BL/2 + RU(tWR/tCK) + 1 Write Precharge All WL + BL/2 + RU(tWR/tCK) + 1 Precharge (to same Bank as Write) BST WL + RU(tWR/tCK) + 1 (for Writes) Precharge All WL + RU(tWR/tCK) + 1 Precharge (to same Bank as Write w/AP) WL + BL/2 + RU(tWR/tCK) + 1 Precharge All WL + BL/2 + RU(tWR/tCK) + 1 Activate (to same Bank as Write w/AP) WL + BL/2 + RU(tWR/tCK) + 1 + RU(tRPpb/tCK) Write w/AP Write or Write w/AP (same bank) illegal Write or Write w/AP (different bank) BL/2 Read or Read w/AP (same bank) illegal Read or Read w/AP (different bank) WL + BL/2 + RU(tWTR/tCK) + 1 Precharge (to same Bank as Precharge) 1 Precharge Precharge All 1 Precharge Precharge 1 All Precharge All 1 clks clks clks clks clks clks 1 1 1 1 1,2 1 clks clks clks clks clks clks clks clks clks clks clks clks clks clks clks clks clks clks clks clks 1 3 3 3 3 1 1 1 1 1 1 1 3 3 3 3 1 1 1 1 Notes: 1. For a given bank, the PRECHARGE period should be counted from the latest PRECHARGE command—either a one-bank PRECHARGE or PRECHARGE ALL—issued to that bank. The PRECHARGE period is satisfied after tRP, depending on the latest PRECHARGE command issued to that bank. 2. Any command issued during the specified minimum delay time is illegal. 3. After READ with auto precharge, seamless READ operations to different banks are supported. After WRITE with auto precharge, seamless WRITE operations to different banks are supported. READ with auto precharge and WRITE with auto precharge must not be interrupted or truncated. Following an auto precharge operation, an ACTIVATE command can be issued to the same bank if the following two conditions are satisfied simultaneously: • The RAS precharge time (tRP) has been satisfied from the clock at which the auto precharge begins. • The RAS cycle time (tRC) from the previous bank activation has been satisfied. Integrated Silicon Solution, Inc. — www.issi.com 52 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C READ Burst with Auto Precharge – RL = 3, BL = 4, RU(tRTP(MIN)/tCK) = 2 - Integrated Silicon Solution, Inc. — www.issi.com 53 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C WRITE Burst operation Followed by PRECHARGE For WRITE cycles, a WRITE recovery time ( tWR) must be provided before a PRECHARGE command can be issued. This delay is referenced from the last valid burst input data to the completion of the burst WRITE. The PRECHARGE command must not be issued prior to the tWR delay. These devices write data to the array in prefetch quadruples (prefetch = 4). An internal WRITE operation can only begin after a prefetch group has been completely latched. The minimum WRITE-to-PRECHARGE time for commands to the same bank is WL + BL/2 + 1 + RU(tWR/tCK) clock cycles. For untruncated bursts, BL is the value set in the mode register. For truncated bursts, BL is the effective burst length. WRITE Burst Followed by PRECHARGE – WL = 1, BL = 4 T0 CK# CK T1 T2 T3 T4 T5 T6 T7 T8 BL/2 RL = 3 CA[9:0] Bankm Col addr a col addr a Bankm row addr ≥ t RPpb t RTP CMD READ w/AP NOP Row addr NOP NOP NOP ACTIVATE NOP NOP NOP DQS# DQS DQ DOUT A0 DOUT A1 DOUT A2 DOUT A3 Transitioning data Integrated Silicon Solution, Inc. — www.issi.com 54 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality REFRESH The REFRESH command is initiated with CS# LOW, CA0 LOW, CA1 LOW, and CA2 HIGH at the rising edge of the clock. Per-bank REFRESH is initiated with CA3 LOW at the rising edge of the clock. All-bank REFRESH is initiated with CA3 HIGH at the rising edge of the clock. Per-bank REFRESH is only supported in devices with eight banks. A per-bank REFRESH command (REFpb) performs a per-bank REFRESH operation to the bank scheduled by the bank counter in the memory device. The bank sequence for per-bank REFRESH is fixed to be a sequential round-robin: 0-1-2-3-4-5-6-7-0-1-.... The bank count is synchronized between the controller and the SDRAM by resetting the bank count to zero. Synchronization can occur upon issuing a RESET command or at every exit from self refresh. Bank addressing for the per-bank REFRESH count is the same as established for the single-bank PRECHARGE command. A bank must be idle before it can be refreshed. The controller must track the bank being refreshed by the per-bank REFRESH command. The REFpb command must not be issued to the device until the following conditions have been met: • tRFCab has been satisfied after the prior REFab command • tRFCpb has been satisfied after the prior REFpb command • tRP has been satisfied after the prior PRECHARGE command to that bank • tRRD has been satisfied after the prior ACTIVATE command (if applicable, for example after activating a row in a different bank than the one affected by the REFpb command) The target bank is inaccessible during per-bank REFRESH cycle time (tRFCpb), however, other banks within the device are accessible and can be addressed during the cycle. During the REFpb operation, any of the banks other than the one being refreshed can be maintained in an active state or accessed by a READ or WRITE command. When the per-bank REFRESH cycle has completed, the affected bank will be in the idle state. After issuing REFpb, the following conditions must be met: • tRFCpb must be satisfied before issuing a REFab command • tRFCpb must be satisfied before issuing an ACTIVATE command to the same bank • tRRD must be satisfied before issuing an ACTIVATE command to a different bank • tRFCpb must be satisfied before issuing another REFpb command Integrated Silicon Solution, Inc. — www.issi.com 55 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C An all-bank REFRESH command (REFab) issues a REFRESH command to all banks. All banks must be idle when REFab is issued (for instance, by issuing a PRECHARGE ALL command prior to issuing an all-bank REFRESH command). REFab also synchronizes the bank count between the controller and the SDRAM to zero. The REFab command must not be issued to the device until the following conditions have been met: • tRFCab has been satisfied following the prior REFab command • tRFCpb has been satisfied following the prior REFpb command • tRP has been satisfied following the prior PRECHARGE commands After an all-bank REFRESH cycle has completed, all banks will be idle. After issuing REFab: • tRFCab latency must be satisfied before issuing an ACTIVATE command • tRFCab latency must be satisfied before issuing a REFab or REFpb command REFRESH Command Scheduling Separation Requirements Command Scheduling Separations related to Refresh Symbol minimum delay from to Activate cmd to any bank . REFpb REFab Activate cmd to same bank as REFpb REFpb Activate cmd to different bank than REFpb REFpb affecting an idle bank (different bank than Activate) t RFCab REFab t RFCpb REFpb REFpb t RRD Activate Notes REFab 1 Activate cmd to different bank than prior Activate Note: A bank must be in the idle state before it is refreshed, so REFab is prohibited following an ACTIVATE command. REFpb is supported only if it affects a bank that is in the idle state. Integrated Silicon Solution, Inc. — www.issi.com 56 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality The LPDDR2 devices provide significant flexibility in scheduling REFRESH commands as long as the required boundary conditions are met (see figure of tSRF Definition). In the most straightforward implementations, a REFRESH command should be scheduled every tREFI. In this case, self refresh can be entered at any time. Users may choose to deviate from this regular refresh pattern, for instance, to enable a period in which no refresh is required. As an example, using a 1Gb LPDDR2 device, the user can choose to issue a refresh burst of 4096 REFRESH commands at the maximum supported rate (limited by tREFBW), followed by an extended period without issuing any REFRESH commands, until the refresh window is complete. The maximum supported time without REFRESH commands is calculated as follows: tREFW - (R/8) × tREFBW= tREFW - R × 4 × tRFCab. For example, a 1Gb device at TC ≤ 85˚C can be operated without a refresh for up to 32ms - 4096 × 4 × 130ns ≈ 30ms. Both the regular and the burst/pause patterns can satisfy refresh requirements if they are repeated in every 32ms window. It is critical to satisfy the refresh requirement in every rolling refresh window during refresh pattern transitions. The supported transition from a burst pattern to a regular distributed pattern is shown in figure of Supported Transition from Repetitive REFRESH Burst . If this transition occurs immediately after the burst refresh phase, all rolling tREFW intervals will meet the minimum required number of REFRESH commands. A nonsupported transition is shown in Figure of Nonsupported Transition from Repetitive REFRESH Burst . In this example, the regular refresh pattern starts after the completion of the pause phase of the burst/pause refresh pattern. For several rolling tREFW intervals, the minimum number of REFRESH commands is not satisfied. Understanding this pattern transition is extremely important, even when only one pattern is employed. In self refresh mode, a regular distributed refresh pattern must be assumed. ISSI recommends entering self refresh mode immediately following the burst phase of a burst/ pause refresh pattern; upon exiting self refresh, begin with the burst phase (see Figure of Recommended Self Refresh Entry and Exit ). Integrated Silicon Solution, Inc. — www.issi.com 57 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Regular Distributed Refresh Pattern Notes: 1. Compared to repetitive burst REFRESH with subsequent REFRESH pause. 2. As an example, in a 1Gb LPDDR2 device at TC ≤ 85˚C, the distributed refresh pattern has one REFRESH command per 7.8μs; the burst refresh pattern has one REFRESH command per 0.52μs, followed by ≈ 30ms without any REFRESH command. Integrated Silicon Solution, Inc. — www.issi.com 58 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Supported Transition from Repetitive REFRESH Burst Notes: 1. Shown with subsequent REFRESH pause to regular distributed refresh pattern. 2. As an example, in a 1Gb LPDDR2 device at TC ≤ 85˚C, the distributed refresh pattern has one REFRESH command per 7.8μs; the burst refresh pattern has one REFRESH command per 0.52μs, followed by ≈ 30ms without any REFRESH command Integrated Silicon Solution, Inc. — www.issi.com 59 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Nonsupported Transition from Repetitive REFRESH Burst Notes: 1. Shown with subsequent REFRESH pause to regular distributed refresh pattern. 2. There are only ≈ 2048 REFRESH commands in the indicated tREFW window. This does not provide the required minimum number of REFRESH commands (R). Integrated Silicon Solution, Inc. — www.issi.com 60 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Recommended Self Refresh Entry and Exit Note: In conjunction with a burst/pause refresh pattern REFRESH Requirements 1. Minimum Number of REFRESH Commands Mobile LPDDR2 requires a minimum number, R, of REFRESH (REFab) commands within any rolling refresh window (tREFW = 32 ms @ MR4[2:0] = 011 or TC ≤ 85˚C). For actual values per density and the resulting average refresh interval (tREFI). For tREFW and tREFI refresh multipliers at different MR4 settings, see the MR4 Device Temperature (MA[7:0] = 04h) table. For devices supporting per-bank REFRESH, a REFab command can be replaced by a full cycle of eight REFpb commands. 2. Burst REFRESH Limitation To limit current consumption, a maximum of eight REFab commands can be issued in any rolling tREFBW (tREFBW = 4 × 8 × tRFCab). This condition does not apply if REFpb commands are used. 3. REFRESH Requirements and Self Refresh If any time within a refresh window is spent in self refresh mode, the number of required REFRESH commands in that window is reduced to the following: R’ = RU〔tSRF / tREFI〕= R - RU ×〔R x tSRF / tREFW〕 Where RU represents the round-up function. Integrated Silicon Solution, Inc. — www.issi.com 61 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality tSRF Definition Notes: 1. Time in self refresh mode is fully enclosed in the refresh window (tREFW). 2. At self refresh entry. 3. At self refresh exit. 4. Several intervals in self refresh during one tREFW interval. In this example, tSRF = tSRF1 +tSRF2. Integrated Silicon Solution, Inc. — www.issi.com 62 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality All-Bank REFRESH Operation Per-Bank REFRESH Operation Notes: 1. Prior to T0, the REFpb bank counter points to bank 0. 2. Operations to banks other than the bank being refreshed are supported during the tRFCpb period Integrated Silicon Solution, Inc. — www.issi.com 63 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality SELF REFRESH Operation The SELF REFRESH command can be used to retain data in the array, even if the rest of the system is powered down. When in the 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 executed by taking CKE LOW, CS# LOW, CA0 LOW, CA1 LOW, and CA2 HIGH at the rising edge of the clock. CKE must be HIGH during the clock cycle preceding a SELF REFRESH command. A NOP command must be driven in the clock cycle following the SELF REFRESH command. After the power-down command is registered, CKE must be held LOW to keep the device in self refresh mode. LPDDR2-S4 devices can operate in self refresh mode in both the standard and extended temperature ranges. These devices also manage self refresh power consumption when the operating temperature changes, resulting in the lowest possible power consumption across the operating temperature range. After the device has entered self refresh mode, all external signals other than CKE are“Don’t Care.” For proper self refresh operation, power supply pins (VDD1, VDD2, VDDQ, and VDDCA) must be at valid levels. VDDQ can be turned off during self refresh. If VDDQ is turned off, VREFDQ must also be turned off. Prior to exiting self refresh, both VDDQ and VREFDQ must be within their respective minimum/maximum operating ranges . VREFDQ can be at any level between 0 and VDDQ; VREFCA can be at any level between 0 and VDDCA during self refresh. Before exiting self refresh, VREFDQ and VREFCA must be within specified limits (see AC and DC Logic Input Measurement Levels for Single-Ended Signals . After entering self refresh mode, the device initiates at least one all-bank REFRESH command internally during tCKESR. The clock is internally disabled during SELF REFRESH operation to save power. The device must remain in self refresh mode for at least tCKESR. The user can change the external clock frequency or halt the external clock one clock after self refresh entry is registered; however, the clock must be restarted and stable before the device can exit SELF REFRESH operation. Exiting self refresh requires a series of commands. First, the clock must be stable prior to CKE returning HIGH. After the self refresh exit is registered, a minimum delay, at least equal to the self refresh exit interval (tXSR), must be satisfied before a valid command can be issued to the device. This provides completion time for any internal refresh in progress. For proper operation, CKE must remain HIGH throughout tXSR, except during self refresh re-entry. NOP commands must be registered on each rising clock edge during tXSR. Using self refresh mode introduces the possibility that an internally timed refresh event could be missed when CKE is driven HIGH for exit from self refresh mode. Upon exiting self refresh, at least one REFRESH command (one all-bank command or eight per-bank commands) must be issued before issuing a subsequent SELF REFRESH command. Integrated Silicon Solution, Inc. — www.issi.com 64 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality SELF REFRESH Operation Notes: 1. Input clock frequency can be changed or stopped during self refresh, provided that upon exiting self-refresh, a minimum of two cycles of stable clocks (tINIT2) are provided, and the clock frequency is between the minimum and maximum frequencies for the particular speed grade. 2. The device must be in the all banks idle state prior to entering self refresh mode. 3. tXSR begins at the rising edge of the clock after CKE is driven HIGH. 4. A valid command can be issued only after tXSR is satisfied. NOPs must be issued during tXSR. Integrated Silicon Solution, Inc. — www.issi.com 65 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Partial-Array Self Refresh – Bank Masking Devices in densities of 64Mb–512Mb are comprised of four banks; densities of 1Gb and higher are comprised of eight banks. Each bank can be configured independently whether or not a SELF REFRESH operation will occur in that bank. One 8-bit mode register (accessible via the MRW command) is assigned to program the bank-masking status of each bank up to eight banks. For bank masking bit assignments, see the MR16 PASR Bank Mask (MA[7:0] = 010h) and MR16 Op-Code Bit Definitions tables. The mask bit to the bank enables or disables a refresh operation of the entire memory space within the bank. If a bank is masked using the bank mask register, a REFRESH operation to the entire bank is blocked and bank data retention is not guaranteed in self refresh mode. To enable a REFRESH operation to a bank, the corresponding bank mask bit must be programmed as “unmasked.” When a bank mask bit is unmasked, the array space being refreshed within that bank is determined by the programmed status of the segment mask bits. Partial-Array Self Refresh – Segment Masking Programming segment mask bits is similar to programming bank mask bits. For densities 1Gb and higher, eight segments are used for masking (see the MR17 PASR Segment Mask (MA[7:0] = 011h) and MR17 PASR Segment Mask Definitions tables). A mode register is used for programming segment mask bits up to eight bits. For densities less than 1Gb, segment masking is not supported. When the mask bit to an address range (represented as a segment) is programmed as“masked,” a REFRESH operation to that segment is blocked. Conversely, when a segment mask bit to an address range is unmasked, refresh to that segment is enabled. A segment masking scheme can be used in place of or in combination with a bank masking scheme. Each segment mask bit setting is applied across all banks. For segment masking bit assignments, see the tables noted above. Bank and Segment Masking Example Segment Mask (MR17) Bank Mask (MR16) Bank 0 Bank 1 Bank 2 Bank 3 Bank 4 Bank 5 Bank 6 Bank 7 0 1 0 0 0 0 0 1 Segment 0 0 – M – – – – – M Segment 1 0 – M – – – – – M Segment 2 1 M M M M M M M M Segment 3 0 – M – – – – – M Segment 4 0 – M – – – – – M Segment 5 0 – M – – – – – M Segment 6 0 – M – – – – – M Segment 7 1 M M M M M M M M Note: This table provides values for an 8-bank device with REFRESH operations masked to banks 1 and 7, and segments 2 and 7. Integrated Silicon Solution, Inc. — www.issi.com 66 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality MODE REGISTER READ The MODE REGISTER READ (MRR) command is used to read configuration and status data from SDRAM mode registers. The MRR command is initiated with CS# LOW, CA0 LOW, CA1 LOW, CA2 LOW, and CA3 HIGH at the rising edge of the clock. The mode register is selected by CA1f–CA0f and CA9r–CA4r. The mode register contents are available on the first data beat of DQ[7:0] after RL × tCK + tDQSCK + tDQSQ and following the rising edge of the clock where MRR is issued. Subsequent data beats contain valid but undefined content, except in the case of the DQ calibration function, where subsequent data beats contain valid content as described in Data Calibration Pattern Description. All DQS are toggled for the duration of the mode register READ burst. The MRR command has a burst length of four. MRR operation (consisting of the MRR command and the corresponding data traffic) must not be interrupted. The MRR command period (tMRR) is two clock cycles. MRR Timing – RL = 3, tMRR = 2 Notes: 1. MRRs to DQ calibration registers MR32 and MR40 are described in DQ Calibration . 2. Only the NOP command is supported during tMRR. 3. Mode register data is valid only on DQ[7:0] on the first beat. Subsequent beats contain valid but undefined data. DQ[MAX:8] contain valid but undefined data for the duration of the MRR burst. 4. Minimum MRR to write latency is RL + RU(tDQSCKmax/tCK) + 4/2 + 1 - WL clock cycles. 5. Minimum MRR to MRW latency is RL + RU(tDQSCKmax/tCK) + 4/2 + 1 clock cycles. Integrated Silicon Solution, Inc. — www.issi.com 67 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality READ bursts and WRITE bursts cannot be truncated by MRR. Following a READ command, the MRR command must not be issued before BL/2 clock cycles have completed. Following a WRITE command, the MRR command must not be issued before WL + 1 + BL/2 + RU(tWTR/tCK) clock cycles have completed. If a READ or WRITE burst is truncated with a BST command, the effective burst length of the truncated burst should be used for the BL value. READ to MRR Timing – RL = 3, tMRR = 2 Notes: 1. The minimum number of clock cycles from the burst READ command to the MRR command is BL/2. 2. Only the NOP command is supported during tMRR. Burst WRITE Followed by MRR – RL = 3, WL = 1, BL = 4 Notes: 1. The minimum number of clock cycles from the burst WRITE command to the MRR command is [WL + 1 + BL/2 + RU(tWTR/ tCK)]. 2. Only the NOP command is supported during tMRR. Integrated Silicon Solution, Inc. — www.issi.com 68 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Temperature Sensor LPDDR2 devices feature a temperature sensor whose status can be read from MR4. This sensor can be used to determine an appropriate refresh rate, determine whether AC timing derating is required in the extended temperature range, and/or monitor the operating temperature. Either the temperature sensor or the device operating temperature can be used to determine whether operating temperature requirements are being met (see Operating Temperature Range table). Temperature sensor data can be read from MR4 using the mode register read protocol. Upon exiting self-refresh or power-down, the device temperature status bits will be no older than tTSI. When using the temperature sensor, the actual device case temperature may be higher than the operating temperature specification that applies for the standard or extended temperature ranges (see table noted above). For example, TCASE could be above 85˚C when MR4[2:0] equals 011b. To ensure proper operation using the temperature sensor, applications must accommodate the parameters in the temperature sensor definitions table. Temperature Sensor Definitions and Operating Conditions Parameter Symbol Max/Min System Temperature Gradient TempGradient Max MR4 Read Interval Max ReadInterval Temperature Sensor Interval tTSI Max System Response Delay SysRespDela y Max Device Temperature Margin TempMargin Max Value Unit Notes Maximum temperature gradient System Dependent C/s experienced by the memory device at the temperature of interest over a range of 2°C. Time period between MR4 READs from the System Dependent ms system. Maximum delay between internal updates 16 ms of MR4. Maximum response time from an MR4 System Dependent ms READ to the system response. Margin above maximum temperature to 2 C support controller response. LPDDR2 devices accommodate the temperature margin between the point at which the device temperature enters the extended temperature range and the point at which the controller reconfigures the system accordingly. To determine the required MR4 polling frequency, the system must use the maximum TempGradient and the maximum response time of the system according to the following equation: TempGradient × (ReadInterval + tTSI + SysRespDelay) ≤ 2°C For example, if TempGradient is 10˚C/s and the SysRespDelay is 1ms: 10°C / s × (ReadInterval + 32ms + 1ms) ≤ 2°C In this case, ReadInterval must not exceed 167ms Integrated Silicon Solution, Inc. — www.issi.com 69 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Temperature Sensor Timing DQ Calibration Mobile LPDDR2 devices feature a DQ calibration function that outputs one of two predefined system timing calibration patterns. For x16 devices, pattern A (MRR to MRR32), and pattern B (MRR to MRR40), will return the specified pattern on DQ0 and DQ8; x32 devices return the specified pattern on DQ0, DQ8, DQ16, and DQ24. For x16 devices, DQ[7:1] and DQ[15:9] drive the same information as DQ0 during the MRR burst. For x32 devices, DQ[7:1], DQ[15:9], DQ[23:17], and DQ[31:25] drive the same information as DQ0 during the MRR burst. MRR DQ calibration commands can occur only in the idle state. Integrated Silicon Solution, Inc. — www.issi.com 70 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality MR32 and MR40 DQ Calibration Timing – RL = 3, tMRR = 2 Note: Only the NOP command is supported during Tmrr Integrated Silicon Solution, Inc. — www.issi.com 71 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Data Calibration Pattern Description Pattern MR# Bit Time 0 Bit Time 1 Bit Time 2 Bit Time 3 Notes Pattern A MR32 1 0 1 0 Reads to MR32 return DQ callibration pattern A Pattern B MR40 0 0 1 1 Reads to MR32 return DQ callibration pattern B MODE REGISTER WRITE Command The MODE REGISTER WRITE (MRW) command is used to write configuration data to the mode registers. The MRW command is initiated with CS# LOW, CA0 LOW, CA1 LOW, CA2 LOW, and CA3 LOW at the rising edge of the clock. The mode register is selected by CA1f–CA0f, CA9r–CA4r. The data to be written to the mode register is contained in CA9f–CA2f. The MRW command period is defined by tMRW. MRWs to read-only registers have no impact on the functionality of the device. MRW can only be issued when all banks are in the idle precharge state. One method of ensuring that the banks are in this state is to issue a PRECHARGE ALL command. MODE REGISTER WRITE Timing – RL = 3, tMRW = 5 T0 CK# CK T1 T2 Tx Tx + 1 t MRW CA[9:0] MR addr CMD MR addr NOP 2 Ty 1 Ty + 1 Ty + 2 t MRW MR data MRW Tx + 2 NOP 2 MR data MRW NOP 2 NOP 2 Valid Truth Table for MRR and MRW Current State All Banks idle Bank(s) Active Command Intermediate State Next State MRR Mode Register Reading (All Banks idle) All Banks idle MRW Mode Register Writing (All Banks idle) All Banks idle MRW (Reset) Restting (Device Auto-Init) All Banks idle MRR Mode Register Reading (Bank(s) idle) Bank(s) Active MRW Not Allowed Not Allowed MRW (Reset) Not Allowed Not Allowed Notes: 1. At time Ty, the device is in the idle state. 2. Only the NOP command is supported during tMRW. Integrated Silicon Solution, Inc. — www.issi.com 72 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality MRW RESET Command The MRW RESET command brings the device to the device auto initialization (resetting) state in the power-on initialization sequence (see RESET Command under Power-Up ). The MRW RESET command can be issued from the idle state. This command resets all mode registers to their default values. Only the NOP command is supported during tINIT4. After MRW RESET, boot timings must be observed until the device initialization sequence is complete and the device is in the idle state. Array data is undefined after the MRW RESET command has completed. For MRW RESET timing, see Figure of Voltage Ramp and Initialization Sequence. MRW ZQ Calibration Commands The MRW command is used to initiate a ZQ calibration command that calibrates output driver impedance across process, temperature, and voltage. LPDDR2-S4 devices support ZQ calibration. To achieve tighter tolerances, proper ZQ calibration must be performed. There are four ZQ calibration commands and related timings: tZQINIT, tZQRESET, tZQCL, and tZQCS. tZQINIT is used for initialization calibration; tZQRESET is used for resetting ZQ to the default output impedance; tZQCL is used for long calibration(s); and tZQCS is used for short calibration(s). See the MR10 Calibration (MA[7:0] = 0Ah) table for ZQ calibration command code definitions. ZQINIT must be performed for LPDDR2 devices. ZQINIT provides an output impedance accuracy of ±15%. After initialization, the ZQ calibration long (ZQCL) can be used to recalibrate the system to an output impedance accuracy of ±15%. A ZQ calibration short (ZQCS) can be used periodically to compensate for temperature and voltage drift in the system. ZQRESET resets the output impedance calibration to a default accuracy of ±30% across process, voltage, and temperature. This command is used to ensure output impedance accuracy to ±30% when ZQCS and ZQCL commands are not used. One ZQCS command can effectively correct at least 1.5% (ZQ correction) of output impedance errors within tZQCS for all speed bins, assuming the maximum sensitivities specified in the tables "output Driver Sensitivity Definition" and "Output Driver Temperature and Voltage Sensitivity" (page 133) are met. The appropriate interval between ZQCS commands can be determined using these tables and system-specific parameters. LPDDR2 devices are subject to temperature drift rate (Tdriftrate) and voltage drift rate (Vdriftrate) in various applications. To accommodate drift rates and calculate the necessary interval between ZQCS commands, apply the following formula. ZQcorrection / 〔(Tsens × Tdriftrate) + (Vsens × Vdriftrate)〕 Where Tsens = MAX (dRONdT) and Vsens = MAX (dRONdV) define temperature and voltage Integrated Silicon Solution, Inc. — www.issi.com 73 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality sensitivities. For example, if Tsens = 0.75%/˚C, Vsens = 0.20%/mV, Tdriftrate = 1˚C/sec, and Vdriftrate =15 mV/ sec, then the interval between ZQCS commands is calculated as: 1.5 / 〔(0.75 × 1) + (0.20 × 15)〕= 0.4s A ZQ calibration command can only be issued when the device is in the idle state with all banks precharged. No other activities can be performed on the data bus during calibration periods (tZQINIT, tZQCL, or tZQCS). The quiet time on the data bus helps to accurately calibrate output impedance. There is no required quiet time after the ZQRESET command. If multiple devices share a single ZQ resistor, only one device can be calibrating at any given time. After calibration is complete, the ZQ ball circuitry is disabled to reduce power consumption. In systems sharing a ZQ resistor between devices, the controller must prevent tZQINIT, tZQCS, and tZQCL overlap between the devices. ZQRESET overlap is acceptable. If the ZQ resistor is absent from the system, ZQ must be connected to VDDCA. In this situation, the device must ignore ZQ calibration commands and the device will use the default calibration settings. ZQ Timings Notes: 1. Only the NOP command is supported during ZQ calibrations. 2. CKE must be registered HIGH continuously during the calibration period. 3. All devices connected to the DQ bus should be High-Z during the calibration process. Integrated Silicon Solution, Inc. — www.issi.com 74 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality ZQ External Resistor Value, Tolerance, and Capacitive Loading To use the ZQ calibration function, a 240 ohm (±1% tolerance) external resistor must be connected between the ZQ pin and ground. A single resistor can be used for each device or one resistor can be shared between multiple devices if the ZQ calibration timings for each device do not overlap. The total capacitive loading on the ZQ pin must be limited. Power-Down Power-down is entered synchronously when CKE is registered LOW and CS# is HIGH at the rising edge of clock. A NOP command must be driven in the clock cycle following power-down entry. CKE must not go LOW while MRR, MRW, READ, or WRITE operations are in progress. CKE can go LOW while any other operations such as ACTIVATE, PRECHARGE, auto precharge, or REFRESH are in progress, but the power-down IDD specification will not be applied until such operations are complete. If power-down occurs when all banks are idle, this mode is referred to as idle power-down; if power-down occurs when there is a row active in any bank, this mode is referred to as active power-down. Entering power-down deactivates the input and output buffers, excluding CK, CK#, and CKE. In power-down mode, CKE must be held LOW; all other input signals are “Don’t Care.” CKE LOW must be maintained until tCKE is satisfied. VREFCA must be maintained at a valid level during power-down. VDDQ can be turned off during power-down. If VDDQ is turned off, VREFDQ must also be turned off. Prior to exiting power-down, both VDDQ and VREFDQ must be within their respective minimum/maximum operating ranges (see AC and DC Operating Conditions). No refresh operations are performed in power-down mode. The maximum duration in power-down mode is only limited by the refresh requirements outlined in REFRESH Command. The power-down state is exited when CKE is registered HIGH. The controller must drive CS# HIGH in conjunction with CKE HIGH when exiting the power-down state. CKE HIGH must be maintained until tCKE is satisfied. A valid, executable command can be applied with power-down exit latency tXP after CKE goes HIGH. Power-down exit latency is defined in the AC Timing section. Integrated Silicon Solution, Inc. — www.issi.com 75 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Power-Down Entry and Exit Timing Note: Input clock frequency can be changed or the input clock stopped during power-down, provided that the clock frequency is between the minimum and maximum specified frequencies for the speed grade in use, and that prior to power-down exit, a minimum of two stable clocks complete. CKE Intensive Environment REFRESH-to-REFRESH Timing in CKE Intensive Environments CK# CK t CKE CKE CMD t CKE t XP t CKE t REFI REFRESH t CKE t XP REFRESH Note: The pattern shown can repeat over an extended period of time. With this pattern, all AC and DC timing and voltage specifications with temperature and voltage drift are ensured. Integrated Silicon Solution, Inc. — www.issi.com 76 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C READ to Power-Down Entry Read to Power-Down entry Notes: 1. CKE must be held HIGH until the end of the burst operation. 2. CKE can be registered LOW at (RL + RU(tDQSCK(MAX)/tCK) + BL/2 + 1) clock cycles after the clock on which the READ command is registered Integrated Silicon Solution, Inc. — www.issi.com 77 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality READ with Auto Precharge to Power-Down Entry Notes: 1. CKE must be held HIGH until the end of the burst operation. 2. CKE can be registered LOW at (RL + RU(tDQSCK/tCK)+ BL/2 + 1) clock cycles after the clock on which the READ command is registered. 3. BL/2 with tRTP = 7.5ns and tRAS (MIN) is satisfied. 4. Start internal PRECHARGE Integrated Silicon Solution, Inc. — www.issi.com 78 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality WRITE to Power-Down Entry Note: CKE can be registered LOW at (WL + 1 + BL/2 + RU(tWR/tCK)) clock cycles after the clock on which the WRITE command is registered. Integrated Silicon Solution, Inc. — www.issi.com 79 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C WRITE with Auto Precharge to Power-Down Entry Write with Auto-precharge to Power-Down entry Notes: 1. CKE can be registered LOW at (WL + 1 + BL/2 + RU(tWR/tCK + 1) clock cycles after the WRITE command is registered. 2. Start internal PRECHARGE Integrated Silicon Solution, Inc. — www.issi.com 80 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality REFRESH Command to Power-Down Entry Note: CKE can go LOW tIHCKE after the clock on which the REFRESH command is registered. ACTIVATE Command to Power-Down Entry Note: CKE can go LOW at tIHCKE after the clock on which the ACTIVATE command is registered PRECHARGE Command to Power-Down Entry Note: CKE can go LOW tIHCKE after the clock on which the PRECHARGE command is registered. Integrated Silicon Solution, Inc. — www.issi.com 81 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality MRR Command to Power-Down Entry Note: CKE can be registered LOW at (RL + RU(tDQSCK/tCK)+ BL/2 + 1) clock cycles after the clock on which the MRR command is registered. MRW Command to Power-Down Entry Note: CKE can be registered LOW tMRW after the clock on which the MRW command is registered Integrated Silicon Solution, Inc. — www.issi.com 82 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Deep Power-Down Deep power-down (DPD) is entered when CKE is registered LOW with CS# LOW, CA0 HIGH, CA1 HIGH, and CA2 LOW at the rising edge of the clock. The NOP command must be driven in the clock cycle following power-down entry. CKE must not go LOW while MRR or MRW operations are in progress. CKE can go LOW while other operations such as ACTIVATE, auto precharge, PRECHARGE, or REFRESH are in progress, however, deep power-down IDD specifications will not be applied until those operations complete. The contents of the array will be lost upon entering DPD mode. In DPD mode, all input buffers except CKE, all output buffers, and the power supply to internal circuitry are disabled within the device. VREFDQ can be at any level between 0 and VDDQ, and VREFCA can be at any level between 0 and VDDCA during DPD. All power supplies (including VREF) must be within the specified limits prior to exiting DPD (see AC and DC Operating Conditions). To exit DPD, CKE must be HIGH, tISCKE must be complete, and the clock must be stable. To resume operation, the device must be fully reinitialized using the power-up initialization sequence. Deep Power-Down Entry and Exit Timing Notes: 1. The initialization sequence can start at any time after Tx + 1. 2. tINIT3 and Tx + 1 refer to timings in the initialization sequence. For details, see Mode Register Definition Integrated Silicon Solution, Inc. — www.issi.com 83 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Input Clock Frequency Changes and Stop Events LPDDR2 support Clock frequency changes and clock stop under the conditions detailed in this section Input Clock Frequency Changes and Clock Stop with CKE LOW During CKE LOW, Mobile LPDDR2 devices support input clock frequency changes and clock stop under the following conditions: • Refresh requirements are met • Only REFab or REFpb commands can be in process • Any ACTIVATE or PRECHARGE commands have completed prior to changing the frequency • Related timing conditions,tRCD and tRP, have been met prior to changing the frequency • The initial clock frequency must be maintained for a minimum of two clock cycles after CKE goes LOW • The clock satisfies tCH(abs) and tCL(abs) for a minimum of two clock cycles prior to CKE going HIGH For input clock frequency changes, tCK(MIN) and tCK(MAX) must be met for each clock cycle. After the input clock frequency is changed and CKE is held HIGH, additional MRW commands may be required to set the WR, RL, etc. These settings may require adjustment to meet minimum timing requirements at the target clock frequency. For clock stop, CK is held LOW and CK# is held HIGH. NO OPERATION Command The NO OPERATION (NOP) command prevents the device from registering any unwanted commands issued between operations. A NOP command can only be issued at clock cycle N when the CKE level is constant for clock cycle N-1 and clock cycle N. The NOP command has two possible encodings: CS# HIGH at the clock rising edge N; and CS# LOW with CA0, CA1, CA2 HIGH at the clock rising edge N. The NOP command will not terminate a previous operation that is still in process, such as a READ burst or WRITE burst cycle Integrated Silicon Solution, Inc. — www.issi.com 84 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Electrical Specifications Absolute Maximum DC 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 above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability. Parameter Symbol Min Max Units Notes VDD1 supply voltage relative to VSS VDD1 -0.4 2.3 V 2 VDD2 supply voltage relative to VSS VDD2 -0.4 1.6 V 2 VDDCA -0.4 1.6 V 2,4 VDDQ -0.4 1.6 V 2,3 VIN, VOUT -0.4 1.6 V 125 °C VDDCA supply voltage relative to VSSCA VDDQ supply voltage relative to VSSQ Voltage on any ball relative to VSS Storage Temperature TSTG -55 5 Notes: 1. Stresses greater than those listed under “Absolute Maximum Ratings” 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 above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability 2. See “Power-Ramp” section in “Power-up, Initialization, and Power-Off” for relationships between power supplies. 3. VREFDQ 0.6 x VDDQ; however, VREFDQ may be VDDQ provided that VREFDQ 300mV. 4. VREFCA 0.6 x VDDCA; however, VREFCA may be VDDCA provided that VREFCA 300mV. 5. Storage Temperature is the case surface temperature on the center/top side of the LPDDR2 device. For the measurement conditions, please refer to JESD51-2 standard. Thermal Resistance Package Theta-ja (Airflow = 0m/s) Theta-jc Units 134-ball 43.3 5.6 °C/W Integrated Silicon Solution, Inc. — www.issi.com 85 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Input/Output Capacitance LPDDR2 1066-466 Parameter MIN MAX MIN MAX Unit Notes Input capacitance, CK and CK# C CK 1.0 2.0 1.0 2.0 pF 2, 3 Input capacitance delta, CK and CK# C DCK 0 0.20 0 0.25 pF 2, 3, 4 Input capacitance, all other inputonly pins CI 1.0 2.0 1.0 2.0 pF 2, 3, 5 Input capacitance delta, all other inputonly pins C DI –0.40 +0.40 –0.50 +0.50 pF 2, 3, 6 Input/output capacitance, DQ, DM, DQS, DQS# C IO 1.25 2.5 1.25 2.5 pF 2, 3, 7, 8 C DDQS 0 0.25 0 0.30 pF 2, 3, 8, 9 C DIO –0.5 +0.5 –0.6 +0.6 pF 2, 3, 8, 10 Input/output capacitance delta, DQS, DQS# Input/output capacitance delta, DQ, DM Symbol LPDDR2 400-200 Notes: 1. TC –25˚C to +105˚C; VDDQ = 1.14–1.3V; VDDCA = 1.14–1.3V; VDD1 = 1.7–1.95V; VDD2 = 1.14–1.3V). 2. This parameter applies to die devices only (does not include package capacitance). 3. This parameter is not subject to production testing. It is verified by design and characterization. The capacitance is measured according to JEP147 (procedure for measuring input capacitance using a vector network analyzer), with VDD1, VDD2, VDDQ, VSS, VSSCA, and VSSQ applied; all other pins are left floating. 4. Absolute value of CCK - CCK#. 5. CI applies to CS#, CKE, and CA[9:0]. 6. CDI = CI - 0.5 × (CCK + CCK#). 7. DM loading matches DQ and DQS. 8. MR3 I/O configuration drive strength OP[3:0] = 0001b (34.3 ohm typical). 9. Absolute value of CDQS and CDQS#. 10. CDIO = CIO - 0.5 × (CDQS + CDQS#) in byte-lane. 11. Maximum external load capacitance on ZQ pin: 5pF. Integrated Silicon Solution, Inc. — www.issi.com 86 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Operation or timing that is not specified is illegal, and after such an event, in order to guarantee proper operation, the LPDDR2 Device must be powered down and then restarted through the specialized initialization sequence before normal operation can continue. Recommended DC Operating Conditions Recommended LPDDR2-S4 DC Operating Conditions Symbol VDD1 LPDDR2-S4B Min Typ Max 1.70 1.80 1.95 DRAM Unit Core Power1 V VDD2 1.14 1.20 1.3 Core Power2 V VDDCA 1.14 1.20 1.3 Input Buffer Power V VDDQ 1.14 1.20 1.3 I/O Buffer Power V NOTE 1 VDD1 uses significantly less power than VDD2 Integrated Silicon Solution, Inc. — www.issi.com 87 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Input Leakage Current Parameter/Condition Symbol Min Max Unit Notes IL -2 2 uA 2 IVREF -1 1 uA 1 Input Leakage current For CA, CKE, CS#, CK, CK# Any input 0V ≤ VIN ≤ VDDCA (All other pins not under test = 0V) VREF supply leakage current VREFDQ = VDDQ/2 or VREFCA = VDDCA/2 (All other pins not under test = 0V) Notes: 1. The minimum limit requirement is for testing purposes. The leakage current on VREFCA and VREFDQ pins should be minimal. 2. Although DM is for input only, the DM leakage shall match the DQ and DQS/DQS# output leakage specification. Operating Temperature Range Parameter/Condition Symbol Commercial Industrial Automotive, A1 Automotive, A2 Toper Min Max Unit 0 85 °C -40 85 -40 85 -40 105 Notes: 1. Operating Temperature is the case surface temperature on the center/top side of the LPDDR2 device. For the measurement conditions, please refer to JESD51-2 standard. Operation outside the range is not permitted. 2. Some applications require operation of LPDDR2 in the maximum temperature conditons in the Extended Temperature Range between 85°C and 105°C case temperature. For LPDDR2 devices, some derating is neccessary to operate in this range. See MR4 and section on Temperature Sensor. 3. Either the device case temperature rating or the temperature sensor (See “Temperature Sensor”) may be used to set an appropriate refresh rate, determine the need for AC timing de-rating and/or monitor the operating temperature. 4. Operation below 85°C is in the Standard Temperature Range. Integrated Silicon Solution, Inc. — www.issi.com 88 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C AC and DC Input Levels for Single-Ended CA and CS# Signals Single-Ended AC and DC Input Levels for CA and CS# Inputs Symbol Parameter LPDDR2-1066 to LPDDR2-466 LPDDR2-400 to LPDDR2-200 Max Single-Ended AC and DC Input Levels for CA and CS# Inputs V (AC) AC input logic high Vref + 0.220 Note IHCA Single-Ended AC and DC Input Levels for CA and CS# Inputs 2 Min Min Max Unit Notes Vref + 0.300 Note 2 V 1, 2 LPDDR2-1066 to LPDDR2-466 to LPDDR2-200 Note 2 Vref - 0.220 LPDDR2-400 Note 2 Vref - 0.300 V 1, 2 VILCA(AC) AC input logic low Symbol Parameter Unit LPDDR2-1066 LPDDR2-400 VIHCA (DC) DC input logic high Vref + 0.130 to LPDDR2-466 VDDCA Vref + 0.200 to LPDDR2-200 VDDCA V Notes 1 Max Min Max Min Symbol Parameter Unit Notes VSSCA Vref 0.130 VSSCA Vref 0.200 V 1 VILCA(DC) DC input logic low Max Min Max Min VIHCA(AC) AC input logic high Vref + 0.220 Note 2 Vref + 0.300 Note 2 V 1, 2 (DC) Reference Voltage for CA and 0.49 * VDDCA 0.51 * VDDCA 0.49 * VDDCA 0.51 * VDDCA V 3, 4 V VRefCA (AC) AC AC input input logic logic low high Vref + 0.220 Note 2 Vref + 0.300 Note 2 V 1, IHCA Note 2 Vref - 0.220 Note 2 Vref - 0.300 V 1, 2 2 V ILCA(AC) CS# inputs (AC) AC input logic low Note 2 Vref - 0.220 Note 2 Vref - 0.300 V 1,12 V VILCA (DC) DC input logic high Vref + 0.130 VDDCA Vref + 0.200 VDDCA V IHCA V (DC) DC DC input input logic logic low high Vref + 0.130 VDDCA Vref + 0.200 VDDCA V 1 Notes: VSSCA Vref - 0.130 VSSCA Vref - 0.200 V 1 VIHCA ILCA(DC) 1. VFor CA and CS# input only pins. Vref = VrefCA(DC). (DC) DC input logic low VSSCA Vref 0.130 VSSCA Vref 0.200 V 0.49 * VDDCA 0.51 * VDDCA 0.49 * VDDCA 0.51 * VDDCA V 3,14 VILCA RefCA(DC) Reference Voltage for CA and 2. VSee “Overshoot and Undershoot Specifications” 0.49 * VDDCA 0.51 * VDDCA 0.49 * VDDCA 0.51 * VDDCA V 3, 4 CS# inputsVoltage for CA and RefCA(DC) Reference 3. The ac peakCS# noise on VRefCA may not allow VRefCA to deviate from VRefCA(DC) by more than +/-1% inputs VDDCA (forInput reference: approx. +/- 12 mV). AC and DC Levels for CKE 4. For reference: approx. VDDCA/2 +/- 12 mV. Single-Ended AC and DC Input Levels for CKE Symbol Parameter Min AC and DC Input Levels for CKE VIHCKE Input High for Level 0.8 * VDDCA AC and DCCKE Input Levels CKE CKE Input Low Level Note 1 V Single-Ended AC and DC Input Levels for CKE ILCKE Single-Ended AC and DC Input Levels for CKE Symbol Parameter Min Symbol Parameter Min VIHCKE CKE Input High Level 0.8 * VDDCA Max Note 1 0.2 * VDDCA Max Max Note 1 V High Level * VDDCA 1 AC and DC CKE InputInput Levels Single-Ended0.8 Data Signals CKE Input Low for Level Note 1 0.2 Note * VDDCA VIHCKE ILCKE CKE Input Low Level Note 1 0.2 * VDDCA VILCKE Note: Single-Ended AC and DC InputSpecifications” Levels for DQ and DM 1. See “Overshoot and Undershoot Unit Notes V V 1 1 Unit Notes Unit Notes V V V V 1 1 1 1 AC and DC Input Levels for Single-Ended Data Signals LPDDR2-1066 to LPDDR2-466 LPDDR2-400 to LPDDR2-200 Parameter AC Symbol and DC Input Levels for Single-Ended Data Signals Max Min Max Min Single-Ended AC and DC Input Levels for DQ and DM VIHDQ(AC) 0.220DM Note 2 Vref + 0.300 Note 2 ACand input logic high Single-Ended AC DC Input Levels forVref DQ+ and LPDDR2-1066 to LPDDR2-466 to LPDDR2-200 VILDQ(AC) Note 2 Vref - 0.220 LPDDR2-400 Note 2 Vref - 0.300 AC input logic low Symbol Parameter LPDDR2-1066 to LPDDR2-466 LPDDR2-400 to LPDDR2-200 VIHDQ (DC) Vref Min + 0.130 VDDQ VrefMin + 0.200 VDDQ DC input logic high Max Max Symbol Parameter Max Min Max Min V (DC) VSSQ Vref 0.130 VSSQ Vref - 0.200 DC input logic low VILDQ Vref + 0.220 Note 2 Vref + 0.300 Note 2 AC input logic high IHDQ(AC) V (AC) Vref + 0.220 Note 2 Vref + 0.300 Note 2 0.49 * VDDQ 0.51 * VDDQ 0.49 * VDDQ 0.51 * VDDQ AC input logic high Reference Voltage for IHDQ RefDQ(DC) VILDQ(AC) Note 2 Vref - 0.220 Note 2 Vref - 0.300 AC input logic low DQ, DM inputs V (AC) Note 2 Vref 0.220 Note 2 Vref 0.300 AC input logic low VILDQ Vref + 0.130 VDDQ Vref + 0.200 VDDQ DC input logic high IHDQ(DC) V (DC) Vref + 0.130 VDDQ Vref + 0.200 VDDQ DC input logic high IHDQ VILDQ(DC) VSSQ Vref - 0.130 VSSQ Vref - 0.200 DC input logic low V (DC) VSSQ Vref 0.130 VSSQ Vref - VDDQ 0.200 DC input logic low VILDQ 0.49 * VDDQ 0.51 * VDDQ 0.49 * VDDQ 0.51 * Reference Voltage for RefDQ(DC) VRefDQ(DC) 0.49 * VDDQ 0.51 * VDDQ 0.49 * VDDQ 0.51 * VDDQ Reference Voltage for DQ, DM inputs DQ, DM inputs Unit Notes V V Unit V Unit V V V V V V V V V V V 1, 2, 5 1, 2, 5 Notes 1 Notes 1 5 1, 2, 1, 1,3,2, 2,45 5 1, 2, 1 5 1 1 3,14 3, 4 Notes: 1. For DQ input only pins. Vref = VrefDQ(DC). 2. See “Overshoot and Undershoot Specifications” 3. The ac peak noise on VRefDQ may not allow VRefDQ to deviate from VRefDQ(DC) by more than +/-1% VDDQ (for reference: approx. +/- 12 mV). 4. For reference: approx. VDDQ/2 +/- 12 mV. Integrated Silicon Solution, Inc. — www.issi.com 89 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C LPDDR2-S4 Refresh Requirement Parameters Parameter Symbol Number of Banks 1Gb Unit 8 Refresh Window Tcase ≤ 85°C tREFW 32 ms Refresh Window 85°C < Tcase ≤ 105°C tREFW 8 ms R 4096 REFab tREFI 7.8 REFpb tREFIpb 0.975 Refresh Cycle time tRFCab 130 ns Per Bank Refresh Cycle time tRFCpb 60 ns Burst Refresh Window = (4 x 8 x tRFCab) tREFBW 4.16 us Required number of REFRESH commands (min) Average time between REFRESH commands (for reference only) Tcase ≤ 85°C" us Integrated Silicon Solution, Inc. — www.issi.com 90 Rev. C 07/02/2021 Rev. C 07/02/2021 tCL(avg) tCK(abs) tCH(abs), allowed tCL(abs), allowed Average low pulse width Absolute Clock Period Absolute clock HIGH pulse width (with allowed jitter) Absolute clock LOW pulse width (with allowed jitter) tJIT(duty), allowed tERR(2per), allowed tERR(3per), allowed tERR(4per), allowed tERR(5per), allowed tERR(6per), allowed tERR(7per), allowed Cumulative error across 2 cycles Cumulative error across 3 cycles Cumulative error across 4 cycles Cumulative error across 5 cycles Cumulative error across 6 cycles Cumulative error across 7 cycles tJIT(cc), allowed Duty cycle Jitter (with allowed jitter) Maximum Clock Jitter between two consecutive clock cycles (with allowed jitter) tJIT(per), allowed tCH(avg) Average high pulse width Clock Period Jitter (with allowed jitter) tCK(avg) Symbol Average Clock Period Max. Frequency Parameter 533 1066 -95 466 933 LPDDR2 4.3 233 466 0.55 max 280 140 -140 300 150 -150 360 180 -180 500 250 -250 ps ps -132 132 -157 157 -175 175 -188 188 -200 200 -209 209 min max min max min max min max min max min max 221 -221 211 -211 199 -199 185 -185 166 -166 140 -140 232 -232 222 -222 209 -209 194 -194 175 256 -256 244 -244 230 -230 214 -214 192 -192 162 147 -175 -162 -147 279 -279 266 -266 251 -251 233 -233 210 -210 177 -177 302 -302 288 -288 272 -272 253 -253 227 -227 191 -191 325 -325 311 -311 293 -293 272 -272 245 348 -348 333 -333 314 -314 291 -291 262 -262 418 -418 399 -399 377 -377 350 -350 314 -314 581 -581 555 -555 524 -524 486 -486 437 -437 368 265 221 206 -245 -368 -265 -221 -206 ps ps ps ps ps ps ps 260 130 -130 max 240 120 tCK(avg) tCK(avg) tCK(avg) tCK(avg) ps tCK(avg) tCK(avg) ns MHz Unit ps 220 110 10 100 200 min((tCH(abs),min - tCH(avg),min), (tCL(abs),min - tCL(avg),min)) * tCK(avg) 200 100 7.5 133 266 max((tCH(abs),max - tCH(avg),max), (tCL(abs),max - tCL(avg),max)) * tCK(avg) 190 95 6 166 333 min 180 90 max -90 0.57 max max 0.43 min min 0.43 0.57 min max tCK(avg)min + tJIT(per),min 0.45 min 5 200 400 min 0.45 0.55 -120 3.75 266 533 min -110 3 333 667 max -100 2.5 400 800 1 00 Clock Timing min t CK max min ~ min max LPDDR2 AC Timing Table (1,2) AC TIMINGS IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Integrated Silicon Solution, Inc. — www.issi.com 91 Rev. C 07/02/2021 -231 231 -237 237 -242 242 min max min max min max tERR(10per), allowed tERR(11per), allowed tERR(12per), allowed tERR(nper), allowed Cumulative error across 10 cycles Cumulative error across 11 cycles Cumulative error across 12 cycles Cumulative error across n = 13, 14 . . . 49, 50 cycles 256 -256 250 -250 244 -244 237 -237 266 -274 274 -282 282 -289 289 -296 296 214 -249 249 -257 257 -263 263 -269 269 323 -323 316 -316 308 -308 299 -299 290 -290 533 LPDDR2 350 -350 342 -342 334 -334 324 -324 314 -314 466 377 -377 368 -368 359 -359 349 -349 338 -338 400 403 -403 395 -395 385 -385 374 -374 362 -362 333 484 -484 474 -474 462 -462 449 -449 435 -435 266 tERR(nper),allowed,min = (1 + 0.68ln(n)) * tJIT(per),allowed,min 224 -266 -214 667 tERR(nper),allowed,max = (1 + 0.68ln(n)) * tJIT(per),allowed,max -224 min max tERR(9per), allowed Cumulative error across 9 cycles 229 -229 800 min 217 933 max -217 min max tERR(8per), allowed Cumulative error across 8 cycles 1066 min max Symbol Parameter min t CK LPDDR2 AC Timing Table (1,2) 672 -672 658 -658 641 -641 624 -624 604 -604 200 ps ps ps ps ps ps Unit IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Integrated Silicon Solution, Inc. — www.issi.com 92 Rev. C 07/02/2021 tDQSCKDS min min min tQSH tQSL tQHP tQH DQS Output High Pulse Width DQS Output Low Pulse Width Data Half Period tRPST Read postamble(9) tLZ(DQ) tHZ(DQS) tHZ(DQ) DQ low-Z from clock(7) DQS high-Z from clock(7) clock(7) DQ high-Z from DQS low-Z from clock tLZ(DQS) (7) Read preamble tRPRE (8) max max min min min min min tQHS DQS - DQ skew Data hold skew factor DQ / DQS output hold time from DQS max max tDQSQ max max 230 200 920 680 330 260 220 1050 780 380 450 540 670 770 280 240 1200 900 340 280 1400 1050 ps ps ps ps tDQSCK(MIN) - (1.4 * tQHS(MAX)) tDQSCK(MAX) - 100 tDQSCK(MAX) + (1.4 * tDQSQ(MAX)) tCK(avg) tCL(abs) - 0.05 ps tCK(avg) tQHP - tQHS 0.9 tCK(avg) ps ps ps ps tCK(avg) 1000 700 - 2100 ps ps ns ns ns us Unit tCL(abs) - 0.05 750 600 - 2000 1800 200 min(tQSH, t QSL) 600 500 - 1900 1350 266 tCK(avg) 480 400 2400 1800 1080 333 tCH(abs) - 0.05 450 370 2100 1550 900 400 tDQSCK(MIN) - 300 400 340 1800 1350 5500 50 max max tDQSCKDM 3 Read Parameters (3) 90 2500 tDQSCKDL DQSCK Delta Long(6) DQSCK Delta Medium(5) DQSCK Delta Short(4) 6 6 min min tZQRESET Calibration Reset Time tDQSCK min DQS output access time from CK/CK# min tZQCL tZQCS Long Calibration Time Short Calibration Time ZQ Calibration Parameters 466 360 533 1 667 min 800 tZQINIT 933 Initialization Calibration Time 1066 LPDDR2 min max Symbol Parameter min t CK LPDDR2 AC Timing Table (1,2) IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Integrated Silicon Solution, Inc. — www.issi.com 93 Rev. C 07/02/2021 1066 933 min min min tDSH tWPRE Write preamble DQS falling edge to CK setup time tWPST min tDSS DQS input low-level width Write postamble min tDQSL DQS falling edge hold time from CK min tDQSH DQS input high-level width 0.35 0.4 0.2 0.2 0.4 0.4 1.25 max 450 tDQSS 430 Write command to 1st DQS latching transition 350 0.75 270 min 235 0.35 210 min 450 tDIPW 430 DQ and DM input pulse width 350 466 min 270 533 min 235 667 tDS 210 800 LPDDR2 tDH Write Parameters (3) min max min t CK DQ and DM input hold time (Vref based) Symbol DQ and DM input setup time (Vref based) Paramete r LPDDR2 AC Timing Table (1,2) 480 480 400 600 600 333 750 750 266 1000 1000 200*5 tCK(avg) tCK(avg) tCK(avg) tCK(avg) tCK(avg) tCK(avg) tCK(avg) tCK(avg) ps ps Unit IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Integrated Silicon Solution, Inc. — www.issi.com 94 Rev. C 07/02/2021 min min min min min min min min min min max max min min tCKE tISCKE(10) tIHCKE(11) tIS (12) tIH (12) tIPW tCKb tISCKEb tIHCKEb tISb tIHb tDQSCKb tDQSQb tQHSb tMRW tMRR CKE min. pulse width (high and low pulse width) CKE input setup time CKE input hold time Address and control input setup time (Vref based) Address and control input hold time (Vref based) Address and control input pulse width Clock Cycle Time CKE Input Setup Time CKE Input Hold Time Address & Control Input Setup Time Address & Control Input Hold Time DQS Output Data Access Time from CK/CK# Data Strobe Edge to Ouput Data Edge tDQSQb - 1.2 Data Hold Skew Factor MODE REGISTER Write command period Mode Register Read command period 1066 933 3 CKE Input Parameters min t CK 800 250 250 290 290 max min min max 2 5 Mode Register Parameters - - - - - - - - Boot Parameters (10 MHz - 55 MHz) (13,14,15) 220 220 Command Address Input Parameters (3) min max Symbol Parameter LPDDR2 AC Timing Table (1,2) 370 370 667 460 460 533 520 520 466 2 5 1.2 1.2 400 600 600 10.0 2.0 1150 1150 2.5 2.5 81 100 0.40 0.25 0.25 3 LPDDR2 740 740 333 900 900 266 1150 1150 200 tCK(avg) tCK(avg) ns ns ns ps ps ns ns ns tCK(avg) ps ps tCK(avg) tCK(avg) tCK(avg) Unit IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Integrated Silicon Solution, Inc. — www.issi.com 95 Rev. C 07/02/2021 WL Write Latency min t CK 3 3 - Typ Fast Typ min max min min min min tWTR tRRD tFAW tDPD Write Recovery Time Internal Write to Read Command Delay Active bank A to Active bank B Four Bank Activate Window Minimum Deep Power Down Time tRAS tWR Row Active Time min 3 Fast tRPab 8-bank 3 Typ Row Precharge Time (19) (all banks) 3 Fast Internal Read to Precharge command delay tRPpb 3 min tRTP LPDDR2-S4 CAS to CAS delay Row Precharge Time (19) (single bank) 3 min tCCD Exit power down to next valid command delay tRCD 2 min tXP 8 2 2 3 2 2 2 min tXSR Self refresh exit to next valid command delay 3 1 3 min min min min tCKESR RAS to CAS Delay (19) 1066 933 800 4 8 4 7 3 6 LPDDR2 SDRAM Core Parameters (16) min max CKE min. pulse width during Self-Refresh (low pulse width during Self-Refresh) tRC RL Read Latency ACTIVE to ACTIVE command period (18) Symbol Parameter LPDDR2 AC Timing Table (1,2) 466 1 3 400 500 50 10 7.5 15 70 42 21 18 50 500 10 10 15 70 60 us ns ns ns ns us ns ns 21 42 ns 18 ns 18 18 ns 15 15 ns tCK(avg) ns ns ns ns tCK(avg) tCK(avg) Unit ns 200 18 266 18 7.5 2 7.5 1 3 333 ns tRFCab + 10 15 tRAS + tRPab (with all-bank Precharge) tRAS + tRPpb (with per-bank Precharge) 2 4 533 15 15 7.5 2 7.5 15 2 5 667 LPDDR2 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Integrated Silicon Solution, Inc. — www.issi.com 96 Rev. C 07/02/2021 max min min min min min tDQSCK (Derated) tRCD (Derated) tRC (Derated) tRAS (Derated) tRP (Derated) tRRD (Derated) tDQSCK De-Rating Core Timings Temperature De-Rating min max Symbol Parameter 1066 933 800 5620 LPDDR2 Temperature De-Rating(17) min tCK 667 Table 103 — LPDDR2 AC Timing Table 6000 466 tRRD + 1.875 tRP + 1.875 tRAS + 1.875 tRC + 1.875 tRCD + 1.875 533 LPDDR2 400 333 266 200 ns ns ns ns ns ps Unit IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Integrated Silicon Solution, Inc. — www.issi.com 97 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Notes: 1. Frequency values are for reference only. Clock cycle time (tCK) is used to determine device capabilities. 2. All AC timings assume an input slew rate of 1 V/ns. 3. READ, WRITE, and input setup and hold values are referenced to VREF. 4. tDQSCKDS is the absolute value of the difference between any two tDQSCK measurements (in a byte lane) within a contiguous sequence of bursts in a 160ns rolling window. tDQSCKDS is not tested and is guaranteed by design. Temperature drift in the system is < 10°C/s. Values do not include clock jitter. 5. tDQSCKDM is the absolute value of the difference between any two tDQSCK measurements (in a byte lane) within a 1.6μs rolling window. tDQSCKDM is not tested and is guaranteed by design. Temperature drift in the system is < 10 °C/s. Values do not include clock jitter. 6. tDQSCKDL is the absolute value of the difference between any two tDQSCK measurements (in a byte lane) within a 32ms rolling window. tDQSCKDL is not tested and is guaranteed by design. Temperature drift in the system is < 10 °C/s. Values do not include clock jitter. 7. For LOW-to-HIGH and HIGH-to-LOW transitions, the timing reference is at the point when the signal crosses the transition threshold (VTT). tHZ and tLZ transitions occur in the same access time (with respect to clock) as valid data transitions. These parameters are not referenced to a specific voltage level but to the time when the device output is no longer driving (for tRPST, tHZ(DQS) and tHZ(DQ)), or begins driving (for tRPRE, tLZ(DQS), tLZ(DQ)). Figure shows a method to calculate the point when device is no longer driving tHZ(DQS) and tHZ(DQ), or begins driving tLZ(DQS), 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. The parameters tLZ(DQS), tLZ(DQ), tHZ(DQS), and tHZ(DQ) are defined as single-ended. The timing parameters tRPRE and tRPST are determined from the differential signal DQS, DQS#. Output Transition Timing (Note #7) V OH 2x X V TT + 2 x Y mV a ct u a l w a ve t HZ(DQS), t HZ(DQ) fo V TT rm V TT - Y mV V OH - X mV V OH - 2x X mV t LZ(DQS), t LZ(DQ) V TT + Y mV X Y 2x Y V OL + 2x X mV V TT - 2 x Y mV T1 T2 Start driving point = 2 × T1 - T2 V TT V OL + X mV V OL T1 T2 End driving point = 2 × T1 - T2 8. Measured from the point when DQS, DQS# begins driving the signal to the point when DQS, DQS# begins driving the first rising strobe edge. 9. Measured from the last falling strobe edge of DQS, DQS# to the point when DQS, DQS# finishes driving the signal. 10. CKE input setup time is measured from CKE reaching a HIGH/LOW voltage level to CK, CK# crossing. 11. CKE input hold time is measured from CK, CK# crossing to CKE reaching a HIGH/LOW voltage level. 12. Input set-up/hold time for signal (CA[9:0], CS#). 13. To ensure device operation before the device is configured, a number of AC boot-timing parameters are defined in this table. Boot parameter symbols have the letter b appended (for example, tCK during boot is tCKb). 14. The LPDDR device will set some mode register default values upon receiving a RESET (MRW) command as specified in ― Mode Register Definition‖. 15. The output skew parameters are measured with default output impedance settings using the reference load. 16. The minimum tCK column applies only when tCK is greater than 6ns. 17. Timing derating applies for operation at 85°C to 105°C when the requirement to derate is indicated by mode register 4 opcode. 18. Use even addressing whenever possible to optimize for long-life. 19. The parts support the parameter values corresponding to Typical. For parts that support Fast values, contact ISSI. Integrated Silicon Solution, Inc. — www.issi.com 98 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Command Input Setup and Hold Timing CK# CK T0 T1 T2 t IS t IH t IS t IH CS# V IL(DC) V IL(AC) T3 V IH(DC) V IH(AC) t IS t IH CA[9:0] CMD CA rise CA fall NOP CA rise t IS t IH CA fall Command CA rise CA fall NOP Transitioning data CA rise CA fall Command Don’t Care Notes: 1. The setup and hold timing shown applies to all commands. 2. Setup and hold conditions also apply to the CKE pin. For timing diagrams related to the CKE pin, see Power-Down . Integrated Silicon Solution, Inc. — www.issi.com 99 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C CA and CS# Setup, Hold, and Derating The For all input signals (CA and CS#), the total required setup time (tIS) and hold time (tIH) is calculated by adding the data sheet tIS (base) and tIH (base) values to the ΔtIS and ΔtIH derating values, respectively. Example: tIS (total setup time) = tIS(base) + ΔtIS. Setup (tIS) typical slew rate for a rising signal is defined as the slew rate between the last crossing of VREF(DC) and the first crossing of VIH(AC)min. The setup (tIS) typical slew rate for a falling signal is defined as the slew rate between the last crossing of VREF(DC) and the first crossing of VIL(AC)max. If the actual signal is always earlier than the typical slew rate line between the shaded VREF(DC)-to-(AC) region, use the typical slew rate for the derating value. If the actual signal is later than the typical slew rate line anywhere between the shaded VREF(DC)-to-AC region, the slew rate of a tangent line to the actual signal from the AC level to the DC level is used for the derating value. The hold (tIH) typical slew rate for a rising signal is defined as the slew rate between the last crossing of VIL(DC)max and the first crossing of VREF(DC). The hold (tIH) typical slew rate for a falling signal is defined as the slew rate between the last crossing of VIH(DC)min and the first crossing of VREF(DC). If the actual signal is always later than the typical slew rate line between the shaded DC-to-VREF(DC) region, use the typical slew rate for the derating value. If the actual signal is earlier than the typical slew rate line anywhere between the shaded DC-to-VREF(DC) region, the slew rate of a tangent line to the actual signal from the DC level to VREF(DC) level is used for the derating value. For a valid transition, the input signal must remain above or below VIH/VIL(AC) for a specified time, tVAC. For slow slew rates the total setup time could be a negative value (that is, a valid input signal will not have reached VIH/VIL(AC) at the time of the rising clock transition). A valid input signal is still required to complete the transition and reach VIH/VIL(AC). For slew rates between the values listed, the derating values are obtained using linear interpolation. Slew rate values are not typically subject to production testing. They are verified by design and characterization. CA and CS# Setup and Hold Base Values (> 400 MHz, 1 V/ns slew rate) Data Rate Parameter 1066 t IS (base) 0 t IH (base) 90 800 667 533 466 30 70 150 240 300 V IH /V IL(AC) = V REF(DC) ±220mV 120 160 240 330 390 V IH /V IL(DC) = V REF(DC) ±130mV 933 Reference Note: AC/DC referenced for 1 V/ns CA and CS# slew rate and 2 V/ns differential CK, CK# slew rate. Integrated Silicon Solution, Inc. — www.issi.com 100 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Derating Values for AC/DC-based tIS/tIH (AC220) - tIS, tIH derating in [ps], AC/DC-based CK, CK# Differential Slew Rate 4.0 V/ns ˂t IS CA, CS# slew rate V/ns 3.0 V/ns ˂t IH ˂t IS 2.0 V/ns ˂t IH ˂t IS ˂t IH 1.8 V/ns ˂t IS ˂t IH 1.6 V/ns ˂t IS ˂t IH 1.4 V/ns ˂t IS ˂t IH 1.2 V/ns ˂t IS ˂t IH 1.0 V/ns ˂t IS ˂t IH 2.0 110 65 110 65 110 65 1.5 74 43 73 43 73 43 89 59 1.0 0 0 0 0 0 0 16 16 32 32 -3 -5 -3 -5 13 11 29 27 45 43 -8 -13 8 3 24 19 40 35 56 55 2 -6 18 10 34 26 50 46 66 78 10 -3 26 13 42 33 58 65 4 -4 20 16 36 48 -7 2 17 34 0.9 0.8 0.7 0.6 0.5 0.4 Note: Shaded cells are not supported. Integrated Silicon Solution, Inc. — www.issi.com 101 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Required Time for Valid Transition with tVAC Above VIH(AC) and Below VIL(AC) t VAC at 300mV (ps) Slew Rate (V/ns) t VAC at 220mV (ps) Min Max Min Max >2.0 75 – 175 – 2.0 57 – 170 – 1.5 50 – 167 – 1.0 38 – 163 – 0.9 34 – 162 – 0.8 29 – 161 – 0.7 22 – 159 – 0.6 13 – 155 – 0.5 0 – 150 – 400 MHz, 1 V/ns slew rate) Data Rate Parameter Reference 1066 933 800 667 533 466 t DS (base) -10 15 50 130 210 230 V IH /V IL(AC) = V REF(DC) ±220mV t DH (base) 80 105 140 220 300 320 V IH /V IL(DC) = V REF(DC) ±130mV Note: AC/DC referenced for 1 V/ns DQ, DM slew rate, and 2 V/ns differential DQS/DQS# slew rate. Integrated Silicon Solution, Inc. — www.issi.com 106 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Derating Values for AC/DC-based tDS/tDH (AC220) - ΔtDS, ΔtDH derating in [ps], AC/DC-based ˂t DS, ˂t DH derating in ps DQS, DQS# Differential Slew Rate 4.0 V/ns 3.0 V/ns 2.0 V/ns 1.8 V/ns 1.6 V/ns 1.4 V/ns 1.2 V/ns 1.0 V/ns ˂t DS ˂t DH ˂t DS ˂t DH ˂t DS ˂t DH ˂t DS ˂t DH ˂t DS ˂t DH ˂t DS ˂t DH ˂t DS ˂t DH ˂t DS ˂t DH DQ, DM slew rate V/ns 2.0 110 65 110 65 110 65 1.5 74 43 73 43 73 43 1.0 0 0 0.9 89 59 0 0 0 0 16 16 32 32 -3 -5 -3 -5 13 11 29 27 45 43 -8 -13 8 3 24 19 40 35 56 55 2 -6 18 10 34 26 50 46 66 78 10 -3 26 13 42 33 58 65 4 -4 20 16 36 48 -7 2 17 34 0.8 0.7 0.6 0.5 0.4 Note: Shaded cells are not supported. Derating Values for AC/DC-based tDS/tDH (AC300) - tDS, tDH derating in [ps], AC/DC-based DQS, DQS# Differential Slew Rate 4.0 V/ns 3.0 V/ns 2.0 V/ns 1.8 V/ns 1.6 V/ns 1.4 V/ns 1.2 V/ns 1.0 V/ns ˂t DS ˂t DH ˂t DS ˂t DH ˂t DS ˂t DH ˂t DS ˂t DH ˂t DS ˂t DH ˂t DS ˂t DH ˂t DS ˂t DH ˂t DS ˂t DH DQ, DM 2.0 slew 1.5 rate V/ns 1.0 0.9 150 100 150 100 150 100 100 67 100 67 100 67 116 83 0 0 0 0 0 0 16 16 32 32 -4 -8 -4 -8 12 8 28 24 44 40 -12 -20 4 -4 20 12 36 28 52 48 -3 -18 13 -2 29 14 45 34 2 -21 18 -5 34 15 50 47 -12 -32 4 -12 20 20 4 -35 -40 -11 -8 0.8 0.7 0.6 0.5 0.4 61 66 Note: Shaded cells are not supported. Integrated Silicon Solution, Inc. — www.issi.com 107 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Required tVAC Above VIH(AC) or Below VIL(AC) for Valid Transition t VAC at 300mV (ps) Slew Rate (V/ns) t VAC at 220mV (ps) Min Max Min Max >2.0 75 – 175 – 2.0 57 – 170 – 1.5 50 – 167 – 1.0 38 – 163 – 0.9 34 – 162 – 0.8 29 – 161 – 0.7 22 – 159 – 0.6 13 – 155 – 0.5 0 – 150 – 4.0 175 75 4.0 170 57 3.0 167 50 2.0 163 38 1.8 162 34 1.6 161 29 1.4 159 22 1.2 155 13 1.0 150 0 < 1.0 150 0 = Single-Ended Requirements for Differential Signals Each individual component of a differential signal (CK, CK#, DQS, and DQS#) must also comply with certain requirements for single-ended signals. CK and CK# must meet VSEH(AC)min/VSEL(AC)max in every half cycle. DQS, DQS# must meet VSEH(AC)min/VSEL(AC)max in every half cycle preceding and following a valid transition. The applicable AC levels for CA and DQ differ by speed bin. Integrated Silicon Solution, Inc. — www.issi.com 122 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Single-Ended Requirements for Differential Signals V DDCA or V DDQ V SEH(AC) Differential Voltage V SEH(AC)min V DDCA /2 or V DDQ /2 CK or DQS V SEL(AC)max V SEL(AC) V SSCA or V SSQ Time Note that while CA and DQ signal requirements are referenced to VREF, the single-ended components of differential signals also have a requirement with respect to VDDQ/2 for DQS, and VDDCA/2 for CK. The transition of single-ended signals through the AC levels is used to measure setup time. For single-ended components of differential signals, the requirement to reach VSEL(AC)max or VSEH(AC)min has no bearing on timing. This requirement does, however, add a restriction on the common mode characteristics of these signals. Single-Ended Levels for CK, CK#, DQS, DQS# LPDDR2-1066 to LPDDR2-466 Symbol V SEH(AC) V SEL(AC) Parameter LPDDR2-400 to LPDDR2-200 Min Max Min Max Unit Notes Single-ended HIGH level for strobes (V DDQ /2) + 0.220 Note 1 (V DDQ /2) + 0.300 Note 1 V 2, 3 Single-ended HIGH level for CK, CK# (V DDCA /2) + 0.220 Note 1 (V DDCA /2) + 0.300 Note 1 V 2, 3 Single-ended LOW level for strobes Note 1 (V DDQ /2) - 0.220 Note 1 (V DDQ /2) + 0.300 V 2, 3 Single-ended LOW level for CK, CK# Note 1 (V DDCA /2) - 0.220 Note 1 (V DDCA /2) + 0.300 V 2, 3 Notes: 1. These values are not defined, however the single-ended signals CK, CK#, DQS, and DQS# must be within the respective limits (VIH(DC)max, VIL(DC)min) for single-ended signals and must comply with the specified limitations for overshoot and undershoot. 2. For CK and CK#, use VIH/VIL(AC) of CA and VREFCA; for DQS and DQS#, use VIH/VIL(AC) of DQ and VREFDQ. If a reduced AC HIGH or AC LOW is used for a signal group, the reduced voltage level also applies. 3. Used to define a differential signal slew rate. Integrated Silicon Solution, Inc. — www.issi.com 123 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Differential Input Crosspoint Voltage To ensure tight setup and hold times as well as output skew parameters with respect to clock and strobe, each crosspoint voltage of differential input signals (CK, CK#, DQS, and DQS#) must meet the specifications in the table "Single-Ended Levels" (page 124). The differential input crosspoint voltage (VIX) is measured from the actual crosspoint of the true signal and complement to the midlevel between VDD and VSS. VIX Definition V DDCA , V DDQ V DDCA , V DDQ CK#, DQS# CK#, DQS# X V IX V IX V DDCA /2, V DDQ /2 X V DDCA /2, X V DDQ /2 V IX X V IX CK, DQS CK, DQS V SSCA , V SSQ V SSCA , V SSQ Crosspoint Voltage for Differential Input Signals (CK, CK#, DQS, DQS#) LPDDR2-1066 to LPDDR2-200 Symbol Parameter Min Max Unit Notes V IXCA(AC) Differential input crosspoint voltage relative to V DDCA /2 for CK and CK# –120 120 mV 1, 2 V IXDQ(AC) Differential input crosspoint voltage relative to V DDQ /2 for DQS and DQ# –120 120 mV 1, 2 Notes: 1. The typical value of VIX(AC) is expected to be about 0.5 × VDD of the transmitting device, and it is expected to track variations in VDD. VIX(AC) indicates the voltage at which differential input signals must cross. 2. For CK and CK#, VREF = VREFCA(DC). For DQS and DQS#, VREF = VREFDQ(DC). Integrated Silicon Solution, Inc. — www.issi.com 124 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Input Slew Rate Differential Input Slew Rate Definition Measured Description 1 From To Defined by Differential input slew rate for rising edge (CK/CK# and DQS/DQS#) V IL,diff,max V IH,diff,min [V IH,diff,min - V IL,diff,max ] / ˂TR diff Differential input slew rate for falling edge (CK/CK# and DQS/DQS#) V IH,diff,min V IL,diff,max [V IH,diff,min - V IL,diff,max ] / ˂TF diff Note: The differential signals (CK/CK# and DQS/DQS#) must be linear between these thresholds. Differential Input Slew Rate Definition for CK, CK#, DQS, and DQS# ΔTR diff Differential Input Voltage ΔTF diff V IH,di ff,min 0 V IL,di ff,max Time Output Characteristics and Operating Conditions Single-Ended AC and DC Output Levels Symbol Parameter Value Unit Notes V OH(AC) AC output HIGH measurement level (for output slew rate) V REF + 0.12 V V OL(AC) AC output LOW measurement level (for output slew rate) V REF - 0.12 V V OH(DC) DC output HIGH measurement level (for I-V curve linearity) 0.9 x V DDQ V 1 V OL(DC) DC output LOW measurement level (for I-V curve linearity) 0.1 x V DDQ V 2 I OZ MMpupd Output leakage current (DQ, DM, DQS, DQS#); DQ, DQS, DQS# are disabled; 0V ื V OUT ื V DDQ MIN –5 ˩A MAX +5 ˩A Delta output impedance between pull-up and pulldown for DQ/DM MIN –15 % MAX +15 % Notes: 1. IOH = –0.1mA. 2. IOL = 0.1mA. Integrated Silicon Solution, Inc. — www.issi.com 125 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Differential AC and DC Output Levels Symbol Parameter Value Unit V OHdiff(AC) AC differential output HIGH measurement level (for output SR) + 0.2 x V DDQ V V OLdiff(AC) AC differential output LOW measurement level (for output SR) - 0.2 x V DDQ V Single-Ended Output Slew Rate With the reference load for timing measurements, the output slew rate for falling and rising edges is defined and measured between VOL(AC) and VOH(AC) for single-ended signals. Differential Input Slew Rate Definition Measured Description From To Defined by Single-ended output slew rate for rising edge V OL(AC) V OH(AC) [V OH(AC) - V OL(AC) ] / ˂TR SE Single-ended output slew rate for falling edge V OH(AC) V OL(AC) [V OH(AC) - V OL(AC) ] / ˂TF SE Note: Output slew rate is verified by design and characterization and may not be subject to production testing. Single-Ended Output Slew Rate Definition Single-Ended Output Voltage (DQ) ΔTF SE ΔTR SE V OH(AC) V REF V OL(AC) Time Integrated Silicon Solution, Inc. — www.issi.com 126 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Single-Ended Output Slew Rate Value Parameter Symbol Min Max Unit Single-ended output slew rate (output impedance = 40 ˖±30%) SRQ SE 1.5 3.5 V/ns Single-ended output slew rate (output impedance = 60 ˖±30%) SRQ SE 1.0 2.5 V/ns 0.7 1.4 – Output slew-rate-matching ratio (pull-up to pull-down) Notes: 1. Definitions: SR = slew rate; Q = output (similar to DQ = data-in, data-out); SE = singleended signals 2. Measured with output reference load. 3. The ratio of pull-up to pull-down slew rate is specified for the same temperature and voltage over the entire temperature and voltage range. For a given output, the ratio represents the maximum difference between pull-up and pull-down drivers due to process variation. 4. The output slew rate for falling and rising edges is defined and measured between VOL(AC) and VOH(AC). 5. Slew rates are measured under typical simultaneous switching output (SSO) conditions, with one-half of DQ signals per data byte driving HIGH and one-half of DQ signals per data byte driving LOW. Differential Output Slew Rate With the reference load for timing measurements, the output slew rate for falling and rising edges is defined and measured between VOL,diff(AC) and VOH,diff(AC) for differential signals. Differential Output Slew Rate Definition Value Parameter Differential output slew rate (output impedance = 40 ˖±30%) Symbol Min Max Unit SRQ diff 3.0 7.0 V/ns Note: Output slew rate is verified by design and characterization and may not be subject to production testing. Differential Output Slew Rate Definition Differential Output Voltage (DQS, DQS#) ΔTF diff ΔTR diff V OH,di ff(AC) 0 V OL,di ff(AC) Time Integrated Silicon Solution, Inc. — www.issi.com 127 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Value Parameter Symbol Min Value Max Unit Parameter Differential output slew rate (output impedance = 40 ˖±30%) Symbol SRQ diff Min 3.0 Max 7.0 Unit V/ns Differential output slew rate (output impedance = 60 ˖±30%) SRQ diff 2.0 5.0 V/ns Notes: 1. Definitions: SR = slew rate; Q = output (similar to DQ = data-in, data-out); SE = singleended signals. 2. Measured with output reference load. 3. The output slew rate for falling and rising edges is defined and measured between VOL(AC) and VOH(AC). 4. Slew rates are measured under typical simultaneous switching output (SSO) conditions, with one-half of DQ signals per data byte driving HIGH and one-half of DQ signals per data byte driving LOW. Integrated Silicon Solution, Inc. — www.issi.com 128 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C AC Overshoot/Undershoot Specification Applies for CA[9:0], CS#, CKE, CK, CK#, DQ, DQS, DQS#, DM Parameter 1066 933 800 667 533 400 333 Unit Maximum peak amplitude provided for overshoot area 0.35 0.35 0.35 0.35 0.35 0.35 0.35 V Maximum peak amplitude provided for undershoot area 0.35 0.35 0.35 0.35 0.35 0.35 0.35 V Maximum area above VDD 1 0.15 0.17 0.20 0.24 0.30 0.40 0.48 V/ns Maximum area below VSS2 0.15 0.17 0.20 0.24 0.30 0.40 0.48 V/ns Notes: 1. VDD stands for VDDCA for CA[9:0], CK, CK#, CS#, and CKE. VDD stands for VDDQ for DQ, DM, DQS, and DQS#. 2. VSS stands for VSSCA for CA[9:0], CK, CK#, CS#, and CKE. VSS stands for VSSQ for DQ, DM, DQS, and DQS#. Overshoot and Undershoot Definition Volts (V) Maximum amplitude V DD Overshoot area Time (ns) V SS Maximum amplitude Undershoot area Notes: 1. VDD stands for VDDCA for CA[9:0], CK, CK#, CS#, and CKE. VDD stands for VDDQ for DQ, DM, DQS, and DQS#. 2. VSS stands for VSSCA for CA[9:0], CK, CK#, CS#, and CKE. VSS stands for VSSQ for DQ, DM, DQS, and DQS#. HSUL_12 Driver Output Timing Reference Load The timing reference loads are not intended as a precise representation of any particular system environment or a depiction of the actual load presented by a production tester. System designers should use IBIS or other simulation tools to correlate the timing reference load to a system environment. Manufacturers correlate to their production test conditions, generally with one or more coaxial transmission lines terminated at the tester electronics. Integrated Silicon Solution, Inc. — www.issi.com 129 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C HSUL_12 Driver Output Reference Load for Timing and Slew Rate LPDDR2 V REF 0.5 × V DDQ 50Ω Output V TT = 0.5 × V DDQ C LOAD = 5pF Note: All output timing parameter values (tDQSCK, tDQSQ, tQHS, tHZ, tRPRE etc.) are reported with respect to this reference load. This reference load is also used to report slew rate. Output Driver Impedance The output driver impedance is selected by a mode register during initialization. The selected value is able to maintain the tight tolerances specified if proper ZQ calibration is performed. Output specifications refer to the default output driver unless specifically stated otherwise. A functional representation of the output buffer is shown in bellow. The output driver impedance RON is defined by the value of the external reference resistor RZQ as follows: RONPU = (VDDQ – VOUT) / ABS(IOUT) When RONPD is turned off. RONPD = VOUT / ABS(IOUT) When RONPU is turned off. Output Driver Chip in drive mode Chip in Drive Mode Output Driver V DDQ To other circuitry (RCV, etc.) I PU R ONPU R ONPD I PD I OUT DQ V OUT V SSQ Integrated Silicon Solution, Inc. — www.issi.com 130 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Output Driver Impedance Characteristics with ZQ Calibration Output driver impedance is defined by the value of the external reference resistor RZQ. Typical RZQ is 240 ohms. Output Driver DC Electrical Characteristics with ZQ Calibration R ONnom 34.3˖ 40.0˖ 48.0˖ 60.0˖ 80.0˖ 120.0˖ Mismatch between pull-up and pull-down Resistor V OUT Min Typ Max Unit R ON34PD 0.5 × V DDQ 0.85 1.00 1.15 R ZQ /7 R ON34PU 0.5 × V DDQ 0.85 1.00 1.15 R ZQ /7 R ON40PD 0.5 × V DDQ 0.85 1.00 1.15 R ZQ /6 R ON40PU 0.5 × V DDQ 0.85 1.00 1.15 R ZQ /6 R ON48PD 0.5 × V DDQ 0.85 1.00 1.15 R ZQ /5 R ON48PU 0.5 × V DDQ 0.85 1.00 1.15 R ZQ /5 R ON60PD 0.5 × V DDQ 0.85 1.00 1.15 R ZQ /4 R ON60PU 0.5 × V DDQ 0.85 1.00 1.15 R ZQ /4 R ON80PD 0.5 × V DDQ 0.85 1.00 1.15 R ZQ /3 R ON80PU 0.5 × V DDQ 0.85 1.00 1.15 R ZQ /3 R ON120PD 0.5 × V DDQ 0.85 1.00 1.15 R ZQ /2 R ON120PU 0.5 × V DDQ 0.85 1.00 1.15 R ZQ /2 +15.00 % MM PUPD –15.00 Notes 5 Notes: 1. Applies across entire operating temperature range after calibration. 2. RZQ = 240Ω. 3. The tolerance limits are specified after calibration, with fixed voltage and temperature. For behavior of the tolerance limits if temperature or voltage changes after calibration. 4. Pull-down and pull-up output driver impedances should be calibrated at 0.5 x VDDQ. 5. Measurement definition for mismatch between pull-up and pull-down, MMPUPD: Measure RONPU and RONPD, both at 0.5 × VDDQ: MMPUPD =( ( RONPU – RONPD ) / RON,nom ) × 100 For example, with MMPUPD (MAX) = 15% and RONPD = 0.85, RONPU must be less than 1.0. Integrated Silicon Solution, Inc. — www.issi.com 131 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Output Driver Temperature and Voltage Sensitivity If temperature and/or voltage change after calibration, the tolerance limits widen Output Driver Sensitivity Definition Symbol Parameter Min Max Unit R ONPD R ON temperature sensitivity 0.00 0.75 %/˚C R ONPU R ON voltage sensitivity 0.00 0.20 %/mV Notes: 1. ΔT = T - T (at calibration). ΔV = V - V (at calibration). 2. dRONdT and dRONdV are not subject to production testing; they are verified by design and characterization. Output Driver Temperature and Voltage Sensitivity Symbol Parameter Min Max Unit R ONPD R ON temperature sensitivity 0.00 0.75 %/˚C R ONPU R ON voltage sensitivity 0.00 0.20 %/mV Output Impedance Characteristics Without ZQ Calibration Output driver impedance is defined by design and characterization as the default setting. Output Driver DC Electrical Characteristics Without ZQ Calibration RON nom 34.3˖ 40.0˖ 48.0˖ 60.0˖ 80.0˖ 120.0˖ Resistor V OUT Min Typ Max Unit R ON34PD 0.5 × V DDQ 0.70 1.00 1.30 R ZQ /7 R ON34PU 0.5 × V DDQ 0.70 1.00 1.30 R ZQ /7 R ON40PD 0.5 × V DDQ 0.70 1.00 1.30 R ZQ /6 R ON40PU 0.5 × V DDQ 0.70 1.00 1.30 R ZQ /6 R ON48PD 0.5 × V DDQ 0.70 1.00 1.30 R ZQ /5 R ON48PU 0.5 × V DDQ 0.70 1.00 1.30 R ZQ /5 R ON60PD 0.5 × V DDQ 0.70 1.00 1.30 R ZQ /4 R ON60PU 0.5 × V DDQ 0.70 1.00 1.30 R ZQ /4 R ON80PD 0.5 × V DDQ 0.70 1.00 1.30 R ZQ /3 R ON80PU 0.5 × V DDQ 0.70 1.00 1.30 R ZQ /3 R ON120PD 0.5 × V DDQ 0.70 1.00 1.30 R ZQ /2 R ON120PU 0.5 × V DDQ 0.70 1.00 1.30 R ZQ /2 Notes: 1. Applies across entire operating temperature range, without calibration. 2. RZQ = 240Ω Integrated Silicon Solution, Inc. — www.issi.com 132 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C I-V Curves R ON = 240˖(R ZQ ) Pull-Down Current (mA) / R Default Value after ZQRESET Voltage (V) Min (mA) Max (mA) Pull-Up ON (ohms) Current (mA) / R With Calibration Min (mA) Max (mA) Default Value after ZQRESET Min (mA) Max (mA) ON (ohms) With Calibration Min (mA) Max (mA) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.05 0.19 0.32 0.21 0.26 –0.19 –0.32 –0.21 –0.26 0.10 0.38 0.64 0.40 0.53 –0.38 –0.64 –0.40 –0.53 0.15 0.56 0.94 0.60 0.78 –0.56 –0.94 –0.60 –0.78 0.20 0.74 1.26 0.79 1.04 –0.74 –1.26 –0.79 –1.04 0.25 0.92 1.57 0.98 1.29 –0.92 –1.57 –0.98 –1.29 0.30 1.08 1.86 1.17 1.53 –1.08 –1.86 –1.17 –1.53 0.35 1.25 2.17 1.35 1.79 –1.25 –2.17 –1.35 –1.79 0.40 1.40 2.46 1.52 2.03 –1.40 –2.46 –1.52 –2.03 0.45 1.54 2.74 1.69 2.26 –1.54 –2.74 –1.69 –2.26 0.50 1.68 3.02 1.86 2.49 –1.68 –3.02 –1.86 –2.49 0.55 1.81 3.30 2.02 2.72 –1.81 –3.30 –2.02 –2.72 0.60 1.92 3.57 2.17 2.94 –1.92 –3.57 –2.17 –2.94 0.65 2.02 3.83 2.32 3.15 –2.02 –3.83 –2.32 –3.15 0.70 2.11 4.08 2.46 3.36 –2.11 –4.08 –2.46 –3.36 0.75 2.19 4.31 2.58 3.55 –2.19 –4.31 –2.58 –3.55 0.80 2.25 4.54 2.70 3.74 –2.25 –4.54 –2.70 –3.74 0.85 2.30 4.74 2.81 3.91 –2.30 –4.74 –2.81 –3.91 0.90 2.34 4.92 2.89 4.05 –2.34 –4.92 –2.89 –4.05 0.95 2.37 5.08 2.97 4.23 –2.37 –5.08 –2.97 –4.23 1.00 2.41 5.20 3.04 4.33 –2.41 –5.20 –3.04 –4.33 1.05 2.43 5.31 3.09 4.44 –2.43 –5.31 –3.09 –4.44 1.10 2.46 5.41 3.14 4.52 –2.46 –5.41 –3.14 –4.52 1.15 2.48 5.48 3.19 4.59 –2.48 –5.48 –3.19 –4.59 1.20 2.50 5.55 3.23 4.65 –2.50 –5.55 –3.23 –4.65 Integrated Silicon Solution, Inc. — www.issi.com 133 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Output Impedance = 240 Ohms, I-V Curves After ZQRESET 6 PD (MAX) PD (MIN) PU MAX) 4 PU (MIN) mA 2 0 –2 –4 –6 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 Voltage Integrated Silicon Solution, Inc. — www.issi.com 134 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Output Impedance = 240 Ohms, I-V Curves After Calibration 6 PD (MAX) PD (MIN) PU MAX) 4 PU (MIN) mA 2 0 –2 –4 –6 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 Voltage Integrated Silicon Solution, Inc. — www.issi.com 135 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Clock Specification The specified clock jitter is a random jitter with Gaussian distribution. Input clocks violating minimum or maximum values may result in device malfunction. Definitions and Calculations Symbol Description t CK(avg) and The average clock period across any consecutive 200-cycle window. Each clock period is calculated from rising clock edge to rising clock edge. nCK Calculation Notes N Σ t CK j /N t CK(avg) = j=1 Where N = 200 Unit t CK(avg) represents the actual clock average t CK(avg)of the input clock under operation. Unit nCK represents one clock cycle of the input clock, counting from actual clock edge to actual clock edge. t CK(avg)can change no more than ±1% within a 100-clock-cycle window, provided that all jitter and timing specifications are met. t CK(abs) The absolute clock period, as measured from one rising clock edge to the next consecutive rising clock edge. t CH(avg) The average HIGH pulse width, as calculated across any 200 consecutive HIGH pulses. 1 N t CH(avg) = Σ t CH j=1 j / ( N × t CK(avg)) Where N = 200 t CL(avg) The average LOW pulse width, as calculated across any 200 consecutive LOW pulses. N t CL(avg) = Σ t CL j=1 j /(N × t CK(avg)) Where N = 200 t JIT(per) The single-period jitter defined as the largest deviation of any signal t CK from t CK(avg). t JIT(per),act The actual clock jitter for a given system. t JIT(per), The specified clock period jitter allowance. t JIT(per) = min/max of t CK – t CK(avg) i Where i = 1 to 200 1 allowed t JIT(cc) t ERR(nper) The absolute difference in clock periods between two consecutive clock cycles. t JIT(cc) defines the cycle-to-cycle jitter. The cumulative error across tive cycles from t CK(avg). t JIT(cc) = max of n multiple consecu- t CK 1 – t CK i i+1 i+n–1 t ERR(nper) = Σ t CK j – ( n × t CK(avg)) 1 j=i t ERR(nper),act The actual cumulative error over given system. t ERR(nper), allowed The specified cumulative error allowance over cycles. t ERR(nper),min The minimum t ERR(nper). n cycles for a n t ERR(nper),min = (1 + 0.68LN(n)) × t JIT(per),min 2 Integrated Silicon Solution, Inc. — www.issi.com 136 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Symbol Description Calculation t ERR(nper),max t ERR(nper). The maximum t JIT(duty) Defined with absolute and average specifications for t CH and t CL, respectively. Notes t ERR(nper),max = (1 + 0.68LN(n)) × 2 t JIT(per),max t JIT(duty),min = MIN( ( t CH(abs),min – t CH(avg),min), ( t CL(abs),min – t CL(avg),min)) × t CK(avg) t JIT(duty),max = MAX(( t CH(abs),max – t CH(avg),max), ( t CL(abs),max – t CL(avg),max)) × t CK(avg) Notes: 1. Not subject to production testing. 2. Using these equations, tERR(nper) tables can be generated for each tJIT(per),act value. tCK(abs), tCH(abs), and tCL(abs) These parameters are specified with their average values; however, the relationship between the average timing and the absolute instantaneous timing (defined in the following table) is applicable at all times. tCK(abs), tCH(abs), and tCL(abs) Definitions Parameter Symbol Absolute clock period t CK(abs) t CK(avg),min + Minimum Absolute clock HIGH pulse width t CH(abs) t CH(avg),min + t JIT(duty),min 2 /t CK(avg)min t CK(avg) Absolute clock LOW pulse width t CL(abs) t CL(avg),min + t JIT(duty),min 2 /t CK(avg)min t CK(avg) t JIT(per),min Unit ps 1 Notes: 1. tCK(avg),min is expressed in ps for this table. 2. tJIT(duty),min is a negative value Integrated Silicon Solution, Inc. — www.issi.com 137 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Clock Period Jitter LPDDR2 devices can tolerate some clock period jitter without core timing parameter derating. This section describes device timing requirements with clock period jitter (tJIT(per)) in excess of the values found in the AC Timing section. Calculating cycle time derating and clock cycle derating are also described. Clock Period Jitter Effects on Core Timing Parameters Core timing parameters (tRCD, tRP, tRTP, tWR, tWRA, tWTR, tRC, tRAS, tRRD, tFAW) extend across multiple clock cycles. Clock period jitter impacts these parameters when measured in numbers of clock cycles. Within the specification limits, the device is characterized and verified to support tnPARAM = RU[tPARAM/tCK(avg)]. During device operation where clock jitter is outside specification limits, the number of clocks or tCK(avg), may need to be increased based on the values for each core timing parameter. Cycle Time Derating for Core Timing Parameters For a given number of clocks (tnPARAM), when tCK(avg) and tERR(tnPARAM) exceed tERR(tnPARAM),allowed, cycle time derating may be required for core timing parameters. tPARAM + tERR( tnPARAM),act – tERR( tnPARAM),allowed – tCK(avg) , 0 tnPARAM CycleTimeDerating = max Conduct cycle time derating analysis for each core timing parameter. The amount of cycle time derating required is the maximum of the cycle time deratings determined for each individual core timing parameter. Clock Cycle Derating for Core Timing Parameters For each core timing parameter and a given number of clocks (tnPARAM), clock cycle derating should be specified with tJIT(per). For a given number of clocks (tnPARAM), when tCK(avg) and (tERR(tnPARAM),act) exceed the supported cumulative tERR(tnPARAM),allowed, if the equation below results in a positive value for a core timing parameter (tCORE), the required clock cycle derating (in clocks) will be that positive value. ClockCycleDerating = RU tPARAM + tERR( tnPARAM),act – tERR( tnPARAM),allowed tCK(avg) – tnPARAM Conduct cycle-time derating analysis for each core timing parameter. Integrated Silicon Solution, Inc. — www.issi.com 138 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C Clock Jitter Effects on Command/Address Timing Parameters Command/address timing parameters (tIS, tIH, tISCKE, tIHCKE, tISb, tIHb, tISCKEb, tIHCKEb) are measured from a command/address signal (CKE, CS, or CA[9:0]) transition edge to its respective clock signal (CK/CK#) crossing. The specification values are not affected by the tJIT(per) applied, as the setup and hold times are relative to the clock signal crossing that latches the command/address. Regardless of clock jitter values, these values must be met. Clock Jitter Effects on READ Timing Parameters tRPRE When the device is operated with input clock jitter, tRPRE must be derated by the tJIT(per),act,max of the input clock that exceeds tJIT(per),allowed,max. Output deratings are relative to the input clock. tRPRE(min,derated) = 0.9 – tJIT(per),act,max – tJIT(per),allowed,max tCK(avg) For example, if the measured jitter into a LPDDR2-800 device has tCK(avg) = 2500ps, tJIT(per),act,min = –172ps, and JIT(per),act,max = +193ps, then tRPRE,min, derated = 0.9 (tJIT(per), act,max - tJIT(per), allowed,max)/tCK(avg) = 0.9 - (193 - 100)/2500 = 0.8628 tCK(avg). tLZ(DQ), tHZ(DQ), tDQSCK, tLZ(DQS), tHZ(DQS) These parameters are measured from a specific clock edge to a data signal transition (DMn or DQm, where: n = 0, 1, 2, or 3; and m = DQ[31:0]), and specified timings must be met with respect to that clock edge. Therefore, they are not affected by tJIT(per). tQSH, tQSL These parameters are affected by duty cycle jitter, represented by tCH(abs)min and tCL(abs)min. Therefore tQSH(abs)min and tQSL(abs)min can be specified with tCH(abs)min and tCL(abs)min. tQSH(abs)min = tCH(abs)min - 0.05 tQSL(abs)min = tCL(abs)min - 0.05. These parameters determine the absolute data-valid window at the device pin. The absolute minimum data-valid window at the device pin = min [(tQSH(abs)min × tCK(avg)min - tDQSQmax - tQHSmax), (tQSL(abs)min × tCK(avg)min - tDQSQmax - tQHSmax)]. This minimum data-valid window must be met at the target frequency regardless of clock jitter. Integrated Silicon Solution, Inc. — www.issi.com 139 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C tRPST tRPST is affected by duty cycle jitter, represented by tCL(abs). Therefore, tRPST(abs)min can be specified by tCL(abs)min. tRPST(abs)min = tCL(abs)min - 0.05 = tQSL(abs)min. Clock Jitter Effects on WRITE Timing Parameters tDS, tDH These parameters are measured from a data signal (DMn or DQm, where n = 0, 1, 2, 3; and m = DQ[31:0]) transition edge to its respective data strobe signal (DQSn, DQSn#: n = 0,1,2,3) crossing. The specification values are not affected by the amount of tJIT(per) applied, because the setup and hold times are relative to the clock signal crossing that latches the command/address. Regardless of clock jitter values, these values must be met. tDSS, tDSH These parameters are measured from a data strobe signal crossing (DQSx, DQSx#) to its clock signal crossing (CK/CK#). The specification values are not affected by the amount of tJIT(per)) applied, because the setup and hold times are relative to the clock signal crossing that latches the command/address. Regardless of clock jitter values, these values must be met. tDQSS This parameter is measured from the clock signal (CK, CK#) crossing to the first latching data strobe signal (DQSx, DQSx#) crossing. When the device is operated with input clock jitter, this parameter must be derated by the actual tJIT(per),act of the input clock in excess of tJIT(per),allowed. tDQSS(min,derated) = 0.75 tDQSS(max,derated) = 1.25 – tJIT(per),act,min – tJIT(per),allowed, min tCK(avg) tJIT(per),act,max – tJIT(per),allowed, max tCK(avg) For example, if the measured jitter into an LPDDR2-800 device has tCK(avg) = 2500ps, tJIT(per),act,min = -172ps, and tJIT(per),act,max = +193ps, then: tDQSS,(min,derated) = 0.75 - (tJIT(per),act,min - tJIT(per),allowed,min)/tCK(avg) = 0.75 - (-172 + 100)/2500 = 0.7788 tCK(avg), and tDQSS,(max,derated) = 1.25 - (tJIT(per),act,max - tJIT(per),allowed,max)/tCK(avg) = 1.25 - (193 - 100)/2500 = 1.2128 tCK(avg). Integrated Silicon Solution, Inc. — www.issi.com 140 Rev. C 07/02/2021 ® Long-term Support World Class Quality IS43/46LD16640C IS43/46LD32320C ORDERING INFORMATION Commercial Range: Tc = 0°C to +85°C Clock Speed Grade Order Part No. Organization Package 400 MHz -25 IS43LD16640C-25BL 64Mb x 16, LPDDR2-S4 134 ball FBGA, lead free IS43LD32320C-25BL 32Mb x 32, LPDDR2-S4 134 ball FBGA, lead free IS43LD16640C-18BL 64Mb x 16, LPDDR2-S4 134 ball FBGA, lead free IS43LD32320C-18BL 32Mb x 32, LPDDR2-S4 134 ball FBGA, lead free 533 MHz -18 Industrial Range: Tc = -40°C to +85°C Clock Speed Grade Order Part No. Organization Package 400 MHz -25 IS43LD16640C-25BLI 64Mb x 16, LPDDR2-S4 134 ball FBGA, lead free IS43LD32320C-25BLI 32Mb x 32, LPDDR2-S4 134 ball FBGA, lead free IS43LD16640C-18BLI 64Mb x 16, LPDDR2-S4 134 ball FBGA, lead free IS43LD32320C-18BLI 32Mb x 32, LPDDR2-S4 134 ball FBGA, lead free 533 MHz -18 Automotive, A1 Range: Tc = -40°C to +85°C Clock Speed Grade Order Part No. Organization Package 400 MHz -25 IS46LD16640C-25BLA1 64Mb x 16, LPDDR2-S4 134 ball FBGA, lead free IS46LD32320C-25BLA1 32Mb x 32, LPDDR2-S4 134 ball FBGA, lead free IS46LD16640C-18BLA1 64Mb x 16, LPDDR2-S4 134 ball FBGA, lead free IS46LD32320C-18BLA1 32Mb x 32, LPDDR2-S4 134 ball FBGA, lead free 533 MHz -18 Automotive, A2 Range: Tc = -40°C to +105°C Clock Speed Grade Order Part No. Organization Package 400 MHz -25 IS46LD16640C-25BLA2 64Mb x 16, LPDDR2-S4 134 ball FBGA, lead free IS46LD32320C-25BLA2 32Mb x 32, LPDDR2-S4 134 ball FBGA, lead free IS46LD16640C-18BLA2 64Mb x 16, LPDDR2-S4 134 ball FBGA, lead free IS46LD32320C-18BLA2 32Mb x 32, LPDDR2-S4 134 ball FBGA, lead free 533 MHz -18 Integrated Silicon Solution, Inc. — www.issi.com 141 Rev. C 07/02/2021 IS43/46LD16640C IS43/46LD32320C ® Long-term Support World Class Quality Integrated Silicon Solution, Inc. — www.issi.com 142 Rev. C 07/02/2021