2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Features
DDR2 SDRAM
MT47R512M4 – 64 Meg x 4 x 8 banks
MT47R256M8 – 32 Meg x 8 x 8 banks
MT47R128M16 – 16 Meg x 16 x 8 banks
Options1
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
• Configuration
– 512 Meg x 4 (64 Meg x 4 x 8 banks)
– 256 Meg x 8 (32 Meg x 8 x 8 banks)
– 128 Meg x 16 (16 Meg x 16 x 8 banks)
• FBGA package (Pb-free) – x16
– 84-ball FBGA (9mm x 12.5mm) Rev. C
• FBGA package (Pb-free) – x4, x8
– 60-ball FBGA (9mm x 11.5mm) Rev. C
• FBGA package (Lead solder) – x16
– 84-ball FBGA (9mm x 12.5mm) Rev. C
• Timing – cycle time
– 2.5ns @ CL = 5 (DDR2-800)
– 2.5ns @ CL = 6 (DDR2-800)
– 3.0ns @ CL = 4 (DDR2-667)
– 3.0ns @ CL = 5 (DDR2-667)
• Self refresh
– Standard
• Operating temperature
– Commercial (0°C ≤ TC ≤ 85°C)
– Industrial (–40°C ≤ TC ≤ 95°C;
–40°C ≤ TA ≤ 85°C)
Revision
•
VDD/VDDQ = +1.55V, 1.5V-1.9V (-0.05V,+0.35V)
Backward compatible with 1.8V DDR2
JEDEC-standard 1.8V I/O (SSTL_18-compatible)
Differential data strobe (DQS, DQS#) option
4n-bit prefetch architecture
Duplicate output strobe (RDQS) option for x8
DLL to align DQ and DQS transitions with CK
8 internal banks for concurrent operation
Programmable CAS latency (CL)
Posted CAS additive latency (AL)
WRITE latency = READ latency - 1 tCK
Programmable burst lengths: 4 or 8
Adjustable data-output drive strength
64ms, 8192-cycle refresh
On-die termination (ODT)
Industrial (IT) temperature option
RoHS-compliant
Supports JEDEC clock jitter specification
Very low power consumption
Note:
Marking
512M4
256M8
128M16
RT
EB
PK
-25E
-25
-3E
-3
None
None
IT
:C
1. Not all options listed can be combined to
define an offered product. Use the Part
Catalog Search on www.micron.com for
product offerings and availability.
Table 1: Key Timing Parameters
Data Rate (MHz)
tRC
Speed Grade
CL = 3
CL = 4
CL = 5
CL = 6
CL = 7
-25E
n/a
533
800
800
n/a
55
-25
n/a
533
667
800
n/a
55
-3E
400
667
667
n/a
n/a
54
-3
400
533
667
n/a
n/a
55
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
1
(ns)
Micron Technology, Inc. reserves the right to change products or specifications without notice.
© 2011 Micron Technology, Inc. All rights reserved.
Products and specifications discussed herein are subject to change by Micron without notice.
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Features
Table 2: Addressing
Parameter
Configuration
512 Meg x 4
256 Meg x 8
128 Meg x 16
64 Meg x 4 x 8 banks
32 Meg x 8 x 8 banks
16 Meg x 16 x 8 banks
Refresh count
8K
8K
8K
Row address
A[14:0] (32K)
A[14:0] (32K)
A[13:0] (16K)
Bank address
BA[2:0] (8)
BA[2:0] (8)
BA[2:0] (8)
A[11, 9:0] (2K)
A[9:0] (1K)
A[9:0] (1K)
Column address
Part Numbers
Figure 1: 2Gb 1.55V DDR2 Part Numbers
Example Part Number: MT47R256M8EB-25 :C
Configuration
Package
:
Speed
Revision
{
MT47R
:C
Configuration
512 Meg x 4
Revision
512M4
256 Meg x 8
256M8
128 Meg x 16
128M16
IT Industrial Temperature
Power
Package
Standard
84-Ball 9.0mm x 12.5mm FBGA
RT
60-Ball 9.0mm x 11.5mm FBGA
EB
84-Ball 9.0mm x 12.5mm FBGA (lead solder)
PK
-25E
-25
-3E
-3
Note:
Blank
Speed Grade
tCK = 2.5ns, CL = 5
tCK = 2.5ns, CL = 6
tCK = 3ns, CL = 4
tCK = 3ns, CL = 5
1. Not all speeds and configurations are available.
FBGA Part Number System
Due to space limitations, FBGA-packaged components have an abbreviated part marking that is different from the
part number. For a quick conversion of an FBGA code, see the FBGA Part Marking Decoder on Micron’s Web site:
http://www.micron.com.
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
2
Micron Technology, Inc. reserves the right to change products or specifications without notice.
© 2011 Micron Technology, Inc. All rights reserved.
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Features
Contents
State Diagram .................................................................................................................................................. 8
Functional Description ..................................................................................................................................... 9
Industrial Temperature ................................................................................................................................ 9
Automotive Temperature ........................................................................................................................... 10
General Notes ............................................................................................................................................ 10
Functional Block Diagrams ............................................................................................................................. 11
Ball Assignments and Descriptions ................................................................................................................. 14
Packaging ...................................................................................................................................................... 18
Package Dimensions .................................................................................................................................. 18
FBGA Package Capacitance ......................................................................................................................... 20
Electrical Specifications – Absolute Ratings ..................................................................................................... 21
Temperature and Thermal Impedance ........................................................................................................ 21
Electrical Specifications – IDD Parameters ........................................................................................................ 24
IDD Specifications and Conditions ............................................................................................................... 24
IDD7 Conditions .......................................................................................................................................... 24
AC Timing Operating Specifications ................................................................................................................ 28
AC and DC Operating Conditions .................................................................................................................... 37
ODT DC Electrical Characteristics ................................................................................................................... 38
Input Electrical Characteristics and Operating Conditions ............................................................................... 39
Output Electrical Characteristics and Operating Conditions ............................................................................. 42
Output Driver Characteristics ......................................................................................................................... 44
Power and Ground Clamp Characteristics ....................................................................................................... 48
AC Overshoot/Undershoot Specification ......................................................................................................... 49
Input Slew Rate Derating ................................................................................................................................ 51
Commands .................................................................................................................................................... 64
Truth Tables ............................................................................................................................................... 64
DESELECT ................................................................................................................................................. 68
NO OPERATION (NOP) .............................................................................................................................. 69
LOAD MODE (LM) ..................................................................................................................................... 69
ACTIVATE .................................................................................................................................................. 69
READ ......................................................................................................................................................... 69
WRITE ....................................................................................................................................................... 69
PRECHARGE .............................................................................................................................................. 70
REFRESH ................................................................................................................................................... 70
SELF REFRESH ........................................................................................................................................... 70
Mode Register (MR) ........................................................................................................................................ 70
Burst Length .............................................................................................................................................. 71
Burst Type ................................................................................................................................................. 72
Operating Mode ......................................................................................................................................... 72
DLL RESET ................................................................................................................................................. 72
Write Recovery ........................................................................................................................................... 73
Power-Down Mode .................................................................................................................................... 73
CAS Latency (CL) ........................................................................................................................................ 74
Extended Mode Register (EMR) ....................................................................................................................... 75
DLL Enable/Disable ................................................................................................................................... 76
Output Drive Strength ................................................................................................................................ 76
DQS# Enable/Disable ................................................................................................................................. 76
RDQS Enable/Disable ................................................................................................................................. 76
Output Enable/Disable ............................................................................................................................... 76
On-Die Termination (ODT) ........................................................................................................................ 77
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Features
Off-Chip Driver (OCD) Impedance Calibration ............................................................................................ 77
Posted CAS Additive Latency (AL) ............................................................................................................... 77
Extended Mode Register 2 (EMR2) .................................................................................................................. 79
Extended Mode Register 3 (EMR3) .................................................................................................................. 80
Initialization .................................................................................................................................................. 81
ACTIVATE ...................................................................................................................................................... 84
READ ............................................................................................................................................................. 86
READ with Precharge ................................................................................................................................. 90
READ with Auto Precharge .......................................................................................................................... 92
WRITE ........................................................................................................................................................... 97
PRECHARGE ................................................................................................................................................. 107
REFRESH ...................................................................................................................................................... 108
SELF REFRESH .............................................................................................................................................. 109
Power-Down Mode ....................................................................................................................................... 111
Precharge Power-Down Clock Frequency Change .......................................................................................... 118
Reset ............................................................................................................................................................. 119
CKE Low Anytime ...................................................................................................................................... 119
ODT Timing .................................................................................................................................................. 121
MRS Command to ODT Update Delay ........................................................................................................ 123
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
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© 2011 Micron Technology, Inc. All rights reserved.
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Features
List of Figures
Figure 1: 2Gb 1.55V DDR2 Part Numbers ......................................................................................................... 2
Figure 2: Simplified State Diagram ................................................................................................................... 8
Figure 3: Functional Block Diagram – 512 Meg x 4 .......................................................................................... 11
Figure 4: Functional Block Diagram – 256 Meg x 8 .......................................................................................... 12
Figure 5: Functional Block Diagram – 128 Meg x 16 ........................................................................................ 13
Figure 6: 60-Ball FBGA – x4, x8 Ball Assignments (Top View) ........................................................................... 14
Figure 7: 84-Ball FBGA – x16 Ball Assignments (Top View) .............................................................................. 15
Figure 8: 84-Ball FBGA Package (9mm x 12.5mm) – x16 ................................................................................... 18
Figure 9: 60-Ball FBGA Package (9mm x 11.5mm) – x4, x8 ............................................................................... 19
Figure 10: Example Temperature Test Point Location ..................................................................................... 22
Figure 11: Single-Ended Input Signal Levels ................................................................................................... 39
Figure 12: Differential Input Signal Levels ...................................................................................................... 40
Figure 13: Differential Output Signal Levels .................................................................................................... 42
Figure 14: Output Slew Rate Load .................................................................................................................. 43
Figure 15: Full Strength Pull-Down Characteristics ......................................................................................... 44
Figure 16: Full Strength Pull-Up Characteristics ............................................................................................. 45
Figure 17: Reduced Strength Pull-Down Characteristics ................................................................................. 46
Figure 18: Reduced Strength Pull-Up Characteristics ...................................................................................... 47
Figure 19: Input Clamp Characteristics .......................................................................................................... 48
Figure 20: Overshoot ..................................................................................................................................... 49
Figure 21: Undershoot .................................................................................................................................. 49
Figure 22: Nominal Slew Rate for tIS .............................................................................................................. 54
Figure 23: Tangent Line for tIS ....................................................................................................................... 54
Figure 24: Nominal Slew Rate for tIH .............................................................................................................. 55
Figure 25: Tangent Line for tIH ...................................................................................................................... 55
Figure 26: Nominal Slew Rate for tDS ............................................................................................................. 60
Figure 27: Tangent Line for tDS ...................................................................................................................... 60
Figure 28: Nominal Slew Rate for tDH ............................................................................................................ 61
Figure 29: Tangent Line for tDH ..................................................................................................................... 61
Figure 30: AC Input Test Signal Waveform Command/Address Balls ............................................................... 62
Figure 31: AC Input Test Signal Waveform for Data with DQS, DQS# (Differential) ........................................... 62
Figure 32: AC Input Test Signal Waveform for Data with DQS (Single-Ended) .................................................. 63
Figure 33: AC Input Test Signal Waveform (Differential) ................................................................................. 63
Figure 34: MR Definition ............................................................................................................................... 71
Figure 35: CL ................................................................................................................................................ 74
Figure 36: EMR Definition ............................................................................................................................. 75
Figure 37: READ Latency ............................................................................................................................... 78
Figure 38: WRITE Latency ............................................................................................................................. 78
Figure 39: EMR2 Definition ........................................................................................................................... 79
Figure 40: EMR3 Definition ........................................................................................................................... 80
Figure 41: DDR2 Power-Up and Initialization ................................................................................................. 81
Figure 42: Example: Meeting tRRD (MIN) and tRCD (MIN) .............................................................................. 84
Figure 43: Multibank Activate Restriction ....................................................................................................... 85
Figure 44: READ Latency ............................................................................................................................... 87
Figure 45: Consecutive READ Bursts .............................................................................................................. 88
Figure 46: Nonconsecutive READ Bursts ........................................................................................................ 89
Figure 47: READ Interrupted by READ ........................................................................................................... 90
Figure 48: READ-to-WRITE ............................................................................................................................ 90
Figure 49: READ-to-PRECHARGE – BL = 4 ...................................................................................................... 91
Figure 50: READ-to-PRECHARGE – BL = 8 ...................................................................................................... 91
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
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© 2011 Micron Technology, Inc. All rights reserved.
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Features
Figure 51:
Figure 52:
Figure 53:
Figure 54:
Figure 55:
Figure 56:
Figure 57:
Figure 58:
Figure 59:
Figure 60:
Figure 61:
Figure 62:
Figure 63:
Figure 64:
Figure 65:
Figure 66:
Figure 67:
Figure 68:
Figure 69:
Figure 70:
Figure 71:
Figure 72:
Figure 73:
Figure 74:
Figure 75:
Figure 76:
Figure 77:
Figure 78:
Figure 79:
Figure 80:
Figure 81:
Figure 82:
Figure 83:
Figure 84:
Figure 85:
Figure 86:
Bank Read – Without Auto Precharge ............................................................................................. 93
Bank Read – with Auto Precharge ................................................................................................... 94
x4, x8 Data Output Timing – tDQSQ, tQH, and Data Valid Window .................................................. 95
x16 Data Output Timing – tDQSQ, tQH, and Data Valid Window ...................................................... 96
Data Output Timing – tAC and tDQSCK .......................................................................................... 97
Write Burst .................................................................................................................................... 99
Consecutive WRITE-to-WRITE ...................................................................................................... 100
Nonconsecutive WRITE-to-WRITE ................................................................................................ 100
WRITE Interrupted by WRITE ....................................................................................................... 101
WRITE-to-READ ........................................................................................................................... 102
WRITE-to-PRECHARGE ................................................................................................................ 103
Bank Write – Without Auto Precharge ............................................................................................ 104
Bank Write – with Auto Precharge ................................................................................................. 105
WRITE – DM Operation ................................................................................................................ 106
Data Input Timing ........................................................................................................................ 107
Refresh Mode ............................................................................................................................... 108
Self Refresh .................................................................................................................................. 110
Power-Down ................................................................................................................................ 112
READ-to-Power-Down or Self Refresh Entry .................................................................................. 114
READ with Auto Precharge-to-Power-Down or Self Refresh Entry .................................................. 114
WRITE-to-Power-Down or Self Refresh Entry ................................................................................ 115
WRITE with Auto Precharge-to-Power-Down or Self Refresh Entry ................................................. 115
REFRESH Command-to-Power-Down Entry ................................................................................. 116
ACTIVATE Command-to-Power-Down Entry ................................................................................ 116
PRECHARGE Command-to-Power-Down Entry ............................................................................ 117
LOAD MODE Command-to-Power-Down Entry ............................................................................ 117
Input Clock Frequency Change During Precharge Power-Down Mode ........................................... 118
RESET Function ........................................................................................................................... 120
ODT Timing for Entering and Exiting Power-Down Mode .............................................................. 122
Timing for MRS Command to ODT Update Delay .......................................................................... 123
ODT Timing for Active or Fast-Exit Power-Down Mode ................................................................. 123
ODT Timing for Slow-Exit or Precharge Power-Down Modes ......................................................... 124
ODT Turn-Off Timings When Entering Power-Down Mode ............................................................ 124
ODT Turn-On Timing When Entering Power-Down Mode ............................................................. 125
ODT Turn-Off Timing When Exiting Power-Down Mode ............................................................... 126
ODT Turn-On Timing When Exiting Power-Down Mode ................................................................ 127
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
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© 2011 Micron Technology, Inc. All rights reserved.
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Features
List of Tables
Table 1: Key Timing Parameters ...................................................................................................................... 1
Table 2: Addressing ......................................................................................................................................... 2
Table 3: FBGA 84-Ball – x16 and 60-Ball – x4, x8 Descriptions .......................................................................... 16
Table 4: Input Capacitance ............................................................................................................................ 20
Table 5: Absolute Maximum DC Ratings ........................................................................................................ 21
Table 6: Temperature Limits .......................................................................................................................... 22
Table 7: Thermal Impedance ......................................................................................................................... 23
Table 8: General IDD Parameters .................................................................................................................... 24
Table 9: IDD7 Timing Patterns (8-Bank Interleave READ Operation) ................................................................. 25
Table 10: DDR2 IDD Specifications and Conditions ......................................................................................... 26
Table 11: AC Operating Specifications and Conditions .................................................................................... 28
Table 12: Recommended DC Operating Conditions (SSTL_18) ........................................................................ 37
Table 13: ODT DC Electrical Characteristics ................................................................................................... 38
Table 14: Input DC Logic Levels ..................................................................................................................... 39
Table 15: Input AC Logic Levels ..................................................................................................................... 39
Table 16: Differential Input Logic Levels ........................................................................................................ 40
Table 17: Differential AC Output Parameters .................................................................................................. 42
Table 18: Output DC Current Drive ................................................................................................................ 42
Table 19: Output Characteristics .................................................................................................................... 43
Table 20: Full Strength Pull-Down Current (mA) ............................................................................................ 44
Table 21: Full Strength Pull-Up Current (mA) ................................................................................................. 45
Table 22: Reduced Strength Pull-Down Current (mA) ..................................................................................... 46
Table 23: Reduced Strength Pull-Up Current (mA) .......................................................................................... 47
Table 24: Input Clamp Characteristics ........................................................................................................... 48
Table 25: Address and Control Balls ............................................................................................................... 49
Table 26: Clock, Data, Strobe, and Mask Balls ................................................................................................. 49
Table 27: AC Input Test Conditions ................................................................................................................ 50
Table 28: DDR2-400/533 Setup and Hold Time Derating Values (tIS and tIH) ................................................... 52
Table 29: DDR2-667/800/1066 Setup and Hold Time Derating Values (tIS and tIH) .......................................... 53
Table 30: DDR2-400/533 tDS, tDH Derating Values with Differential Strobe ..................................................... 56
Table 31: DDR2-667/800/1066 tDS, tDH Derating Values with Differential Strobe ............................................ 57
Table 32: Single-Ended DQS Slew Rate Derating Values Using tDSb and tDHb .................................................. 58
Table 33: Single-Ended DQS Slew Rate Fully Derated (DQS, DQ at VREF) at DDR2-667 ..................................... 58
Table 34: Single-Ended DQS Slew Rate Fully Derated (DQS, DQ at VREF) at DDR2-533 ..................................... 59
Table 35: Single-Ended DQS Slew Rate Fully Derated (DQS, DQ at VREF) at DDR2-400 ..................................... 59
Table 36: Truth Table – DDR2 Commands ..................................................................................................... 64
Table 37: Truth Table – Current State Bank n – Command to Bank n ............................................................... 65
Table 38: Truth Table – Current State Bank n – Command to Bank m .............................................................. 67
Table 39: Minimum Delay with Auto Precharge Enabled ................................................................................. 68
Table 40: Burst Definition .............................................................................................................................. 72
Table 41: READ Using Concurrent Auto Precharge ......................................................................................... 92
Table 42: WRITE Using Concurrent Auto Precharge ........................................................................................ 98
Table 43: Truth Table – CKE ......................................................................................................................... 113
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
State Diagram
State Diagram
Figure 2: Simplified State Diagram
CKE_L
Initialization
sequence
OCD
default
Self
refreshing
SR
PRE
H
KE_
C
Setting
MRS
EMRS
Idle
all banks
precharged
(E)MRS
REFRESH
CK
E_
CK
H
Refreshing
L
E_
E_
CK
L
Precharge
powerdown
CKE_L
Automatic Sequence
Command Sequence
ACT
CKE_L
ACT = ACTIVATE
CKE_H = CKE HIGH, exit power-down or self refresh
CKE_L = CKE LOW, enter power-down
(E)MRS = (Extended) mode register set
PRE = PRECHARGE
PRE_A = PRECHARGE ALL
READ = READ
READ A = READ with auto precharge
REFRESH = REFRESH
SR = SELF REFRESH
WRITE = WRITE
WRITE A = WRITE with auto precharge
Activating
_L
CKE
Active
powerdown
CK CKE_
E_L H
Bank
active
E
EA
RE
AD
W
A
Writing
READ
WRITE
REA
Reading
A
ITE
WR
DA
READ A
PR
WRITE A
READ
AD
RIT
W
RE
RIT
WRITE
E_
PR
,
E
A
PRE, PRE_A
PR
E_
PR
A
E,
Writing
with
auto
precharge
Reading
with
auto
precharge
Precharging
Note:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
1. This diagram provides the basic command flow. It is not comprehensive and does not
identify all timing requirements or possible command restrictions such as multibank interaction, power down, entry/exit, etc.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Functional Description
Functional Description
The 1.55V DDR2 SDRAM is a lower-voltage device and backward compatible with the
1.8V DDR2 device. The differences between the 1.55V and 1.8V DDR2 devices will be
noted.
The DDR2 SDRAM 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 balls. A single
read or write access for the DDR2 SDRAM effectively consists of a single 4n-bit-wide, oneclock-cycle data transfer at the internal DRAM core and four corresponding n-bit-wide,
one-half-clock-cycle data transfers at the I/O balls.
A bidirectional data strobe (DQS, DQS#) is transmitted externally, along with data, for
use in data capture at the receiver. DQS is a strobe transmitted by the DDR2 SDRAM
during READs and by the memory controller during WRITEs. DQS is edge-aligned with
data for READs and center-aligned with data for WRITEs. The x16 offering has two data
strobes, one for the lower byte (LDQS, LDQS#) and one for the upper byte (UDQS, UDQS#).
The DDR2 SDRAM operates from a differential clock (CK and CK#); the crossing of CK
going HIGH and CK# going LOW will be referred to as the positive edge of CK. Commands (address and control signals) are registered at every positive edge of CK. Input
data is registered on both edges of DQS, and output data is referenced to both edges of
DQS as well as to both edges of CK.
Read and write accesses to the DDR2 SDRAM 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 bits registered coincident
with the ACTIVATE command are used to select the bank and row 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.
The DDR2 SDRAM provides for programmable read or write burst lengths of four or
eight locations. DDR2 SDRAM supports interrupting a burst read of eight with another
read or a burst write of eight with another write. An auto precharge function may be
enabled to provide a self-timed row precharge that is initiated at the end of the burst
access.
As with standard DDR SDRAM, the pipelined, multibank architecture of DDR2 SDRAM
enables concurrent operation, thereby providing high, effective bandwidth by hiding
row precharge and activation time.
A self refresh mode is provided, along with a power-saving, power-down mode.
All inputs are compatible with the JEDEC standard for SSTL_18. All full drive-strength
outputs are SSTL_18-compatible.
Industrial Temperature
The industrial temperature (IT) option, if offered, has two simultaneous requirements:
ambient temperature surrounding the device cannot be less than –40°C or greater than
+85°C, and the case temperature cannot be less than –40°C or greater than +95°C. JEDEC specifications require the refresh rate to double when TC exceeds +85°C; this also
requires use of the high-temperature self refresh option. Additionally, ODT resistance,
the input/output impedance and IDD values must be derated when TC is < 0°C or > +85°C.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Functional Description
Automotive Temperature
The automotive temperature (AT) option, if offered, has two simultaneous requirements: ambient temperature surrounding the device cannot be less than –40°C or
greater than +105°C, and the case temperature cannot be less than –40°C or greater
than +105°C. JEDEC specifications require the refresh rate to double when TC exceeds
+85°C; this also requires use of the high-temperature self refresh option. Additionally,
ODT resistance, the input/output impedance and IDD values must be derated when TC
is < 0°C or > +85°C.
General Notes
• The functionality and the timing specifications discussed in this data sheet are for the
DLL-enabled mode of operation.
• Throughout the data sheet, the various figures and text refer to DQs as “DQ.” The DQ
term is to be interpreted as any and all DQ collectively, unless specifically stated otherwise. Additionally, the x16 is divided into 2 bytes: the lower byte and the upper byte.
For the lower byte (DQ0–DQ7), DM refers to LDM and DQS refers to LDQS. For the
upper byte (DQ8–DQ15), DM refers to UDM and DQS refers to UDQS.
• Complete functionality is described throughout the document, and any page or diagram may have been simplified to convey a topic and may not be inclusive of all
requirements.
• Any specific requirement takes precedence over a general statement.
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Functional Block Diagrams
Functional Block Diagrams
The DDR2 SDRAM is a high-speed CMOS, dynamic random access memory. It is internally configured as a multibank DRAM.
Figure 3: Functional Block Diagram – 512 Meg x 4
ODT
CKE
CK
CK#
Command
decode
CS#
RAS#
CAS#
WE#
Control
logic
15
Mode
registers
18
Refresh 15
counter
15
Rowaddress
MUX
Bank 7
Bank 7
Bank 6
Bank 6
Bank 5
Bank 5
Bank 4
Bank 4
Bank 3
Bank 3
Bank 2
Bank 2
Bank 1
Bank 1
Bank 0
Bank 0
rowMemory array
address
latch 32,768 (32,768 x 512 x 16)
and
decoder
4
16
Read
latch
MUX
16
1
Address
18
register
2
3
11
Bank
control
logic
Columnaddress
counter/
latch
Write
FIFO
16 and
drivers
512
(x16)
9
Column
decoder
CK, CK#
2
COL0, COL1
CK out
CK in
sw1
4
4
4
4
DRVRS
DATA
DQS
generator
I/O gating
DM mask logic
ODT control Vdd Q
sw1 sw2 sw3
DLL
4
Sense amplifiers
8,192
A0–A14,
BA0–BA2
CK, CK#
COL0, COL1
Input
registers
2
sw2 sw3
R1
R2
R3
R1
R2
R3
sw1
sw2 sw3
DQS, DQS#
1
1
1
1
R1
R2
R3
R1
R2
R3
sw1
sw2 sw3
1
1
1
1
4
4
16 4
4
4
R1
R2
R3
4
4
R1
R2
R3
Mask
Data
DQ0–DQ3
4
DQS, DQS#
RCVRS
4
DM
2
Vss Q
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Functional Block Diagrams
Figure 4: Functional Block Diagram – 256 Meg x 8
ODT
CKE
CK
CK#
Command
decode
CS#
RAS#
CAS#
WE#
Control
logic
15
Mode
registers
18
Refresh 15
counter
15
Rowaddress
MUX
Bank 7
Bank 7
Bank 6
Bank 6
Bank 5
Bank 5
Bank 4
Bank 4
Bank 3
Bank 3
Bank 2
Bank 2
Bank 1
Bank 1
Bank 0
Bank 0
rowMemory array
address
latch 32,768 (32,768 x 256 x 32)
and
decoder
Address
18 register
8
32
Read
latch
2
3
10
Bank
control
logic
Columnaddress
counter/
latch
MUX
DRVRS
Data
2
UDQS, UDQS#
Input LDQS, LDQS#
registers
2
2
32
Write
FIFO
32 and
drivers
256
(x32)
8
sw1
8
8
8
DQS
generator
I/O gating
DM mask logic
Column
decoder
CK,CK#
2
COL0, COL1
CK out
CK in
ODT control
VddQ
sw1 sw2 sw3
DLL
8
Sense amplifers
8,192
A0–A14,
BA0–BA2
CK, CK#
COL0, COL1
4
Mask
2
2
2
2
2
sw2 sw3
R1
R2
R3
R1
R2
R3
sw1
sw2 sw3
R1
R2
R3
R1
R2
R3
2
8
8
32 8
8
8
R1
R2
R3
8
8
R1
R2
R3
8
RCVRS
8
DQS, DQS#
RDQS#
2
Data
DQ0–DQ7
sw1
sw2 sw3
RDQS
DM
2
VssQ
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Functional Block Diagrams
Figure 5: Functional Block Diagram – 128 Meg x 16
ODT
CKE
CK
CK#
Command
decode
CS#
RAS#
CAS#
WE#
Control
logic
14
Mode
registers
16
Refresh 14
counter
14
Rowaddress
MUX
Bank 7
Bank 7
Bank 6
Bank 6
Bank 5
Bank 5
Bank 4
Bank 4
Bank 3
Bank 3
Bank 2
Bank 2
Bank 1
Bank 1
Bank 0
Bank 0
rowMemory array
address
latch 16,384 (16,384 x 256 x 64)
and
decoder
16 Address
register
Read
latch
2
3
10
Bank
control
logic
Columnaddress
counter/
latch
16
16
DRVRS
MUX DATA
4
UDQS, UDQS#
Input LDQS, LDQS#
registers
2
2
64
8
2
WRITE
2
FIFO Mask
2
and
64
drivers
16
256
(x64)
8
sw1
16
DQS
generator
I/O gating
DM mask logic
Column
decoder
CK, CK#
2
COL0, COL1
CK out
CK in
ODT control
VddQ
sw1 sw2 sw3
DLL
16
64
Sense amplifier
16,384
A0–A13,
BA0–BA2
CK, CK#
COL0, COL1
16
64 16
16
Data
16
2
2
2
2
sw2 sw3
R1
R2
R3
R1
R2
R3
sw1
sw2 sw3
R1
R2
R3
R1
R2
R3
sw1
sw2 sw3
DQ0–DQ15
UDQS, UDQS#
LDQS, LDQS#
RCVRS
16
16 16
16
R1
R2
R3
16
R1
R2
R3
UDM, LDM
4
VssQ
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Ball Assignments and Descriptions
Ball Assignments and Descriptions
Figure 6: 60-Ball FBGA – x4, x8 Ball Assignments (Top View)
1
2
3
4
5
6
7
8
9
A
VDD NF, RDQS#/NU VSS
VSSQ DQS#/NU VDDQ
B
NF, DQ6
VSSQ DM, DM/RDQS
DQS
VSSQ
NF, DQ7
C
VDDQ
DQ1
VDDQ
VDDQ
DQ0
VDDQ
NF, DQ4
VSSQ
DQ3
DQ2
VSSQ
NF, DQ5
VDDL
VREF
VSS
VSSDL
CK
VDD
CKE
WE#
RAS#
CK#
ODT
BA0
BA1
CAS#
CS#
A10
A1
A2
A0
A3
A5
A6
A4
A7
A9
A11
A8
A12
A14
RFU
A13
D
E
F
G
BA2
H
VDD
J
VSS
K
VSS
L
VDD
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Ball Assignments and Descriptions
Figure 7: 84-Ball FBGA – x16 Ball Assignments (Top View)
1
2
3
4
5
6
7
8
9
VDD
NC
VSS
DQ14
VSSQ
UDM
UDQS
VSSQ
DQ15
VDDQ
DQ9
VDDQ
VDDQ
DQ8
VDDQ
DQ12
VSSQ
DQ11
DQ10
VSSQ
DQ13
VDD
NC
VSS
DQ6
VSSQ
LDM
LDQS
VSSQ
DQ7
VDDQ
DQ1
VDDQ
VDDQ
DQ0
VDDQ
DQ4
VSSQ
DQ3
DQ2
VSSQ
DQ5
VDDL
VREF
VSS
VSSDL
CK
VDD
CKE
WE#
RAS#
CK#
ODT
BA0
BA1
CAS#
CS#
A10
A1
A2
A0
A3
A5
A6
A4
A7
A9
A11
A8
A12
RFU
RFU
A13
A
VSSQ UDQS#/NU VDDQ
B
C
D
E
VSSQ LDQS#/NU VDDQ
F
G
H
J
K
L
BA2
M
VDD
N
VSS
P
VSS
R
VDD
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
15
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© 2011 Micron Technology, Inc. All rights reserved.
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Ball Assignments and Descriptions
Table 3: FBGA 84-Ball – x16 and 60-Ball – x4, x8 Descriptions
Symbol
Type
Description
A[13:0] (x16)
A[14:0] (x4, x8)
Input
Address inputs: Provide the row address for ACTIVE commands, and the column address and auto precharge bit (A10) for READ/WRITE commands, to select one location out
of the memory array in the respective bank. A10 sampled during a PRECHARGE command determines whether the PRECHARGE applies to one bank (A10 LOW, bank selected
by BA[2:0]) or all banks (A10 HIGH). The address inputs also provide the op-code during a
LOAD MODE command.
BA[2:0]
Input
Bank address inputs: BA[2:0] define to which bank an ACTIVE, READ, WRITE, or PRECHARGE command is being applied. BA[2:0] define which mode register, including MR,
EMR, EMR(2), and EMR(3), is loaded during the LOAD MODE command.
CK, CK#
Input
Clock: CK and CK# are differential clock inputs. All address and control input signals are
sampled on the crossing of the positive edge of CK and negative edge of CK#. Output
data (DQ and DQS/DQS#) is referenced to the crossings of CK and CK#.
CKE
Input
Clock enable: CKE (registered HIGH) activates and CKE (registered LOW) deactivates
clocking circuitry on the DDR2 SDRAM. The specific circuitry that is enabled/disabled is
dependent on the DDR2 SDRAM configuration and operating mode. CKE LOW provides
precharge power-down and SELF REFRESH operation (all banks idle), or ACTIVATE powerdown (row active in any bank). CKE is synchronous for power-down entry, power-down
exit, output disable, and for self refresh entry. CKE is asynchronous for SELF REFRESH exit. Input buffers (excluding CK, CK#, CKE, and ODT) are disabled during power-down.
Input buffers (excluding CKE) are disabled during self refresh. CKE is an SSTL_18 input
but will detect a LVCMOS LOW level once VDD is applied during first power-up. After VREF
has become stable during the power on and initialization sequence, it must be maintained for proper operation of the CKE receiver. For proper SELF REFRESH operation, VREF
must be maintained.
CS#
Input
Chip select: CS# enables (registered LOW) and disables (registered HIGH) the command
decoder. All commands are masked when CS# is registered high. CS# provides for external bank selection on systems with multiple ranks. CS# is considered part of the command code.
LDM, UDM (DM)
Input
Input data mask: DM is an input mask signal for write data. Input data is masked when
DM is concurrently sampled HIGH during a WRITE access. DM is sampled on both edges
of DQS. Although DM balls are input-only, the DM loading is designed to match that of
DQ and DQS balls. LDM is DM for lower byte DQ[7:0] and UDM is DM for upper byte
DQ[15:8].
ODT
Input
On-die termination: ODT (registered HIGH) enables termination resistance internal to
the DDR2 SDRAM. When enabled, ODT is only applied to each of the following balls:
DQ[15:0], LDM, UDM, LDQS, LDQS#, UDQS, and UDQS# for the x16; DQ[7:0], DQS, DQS#,
RDQS, RDQS#, and DM for the x8; DQ[3:0], DQS, DQS#, and DM for the x4. The ODT input
will be ignored if disabled via the LOAD MODE command.
RAS#, CAS#, WE#
Input
Command inputs: RAS#, CAS#, and WE# (along with CS#) define the command being
entered.
DQ[15:0] (x16)
DQ[3:0] (x4)
DQ[7:0] (x8)
I/O
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Data input/output: Bidirectional data bus for 128 Meg x 16.
Bidirectional data bus for 512 Meg x 4.
Bidirectional data bus for 256 Meg x 8.
16
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Ball Assignments and Descriptions
Table 3: FBGA 84-Ball – x16 and 60-Ball – x4, x8 Descriptions (Continued)
Symbol
Type
DQS, DQS#
I/O
Description
Data strobe: Output with read data, input with write data for source synchronous operation. Edge-aligned with read data, center-aligned with write data. DQS# is only used
when differential data strobe mode is enabled via the LOAD MODE command.
LDQS, LDQS#
I/O
Data strobe for lower byte: Output with read data, input with write data for source
synchronous operation. Edge-aligned with read data, center-aligned with write data.
LDQS# is only used when differential data strobe mode is enabled via the LOAD MODE
command.
UDQS, UDQS#
I/O
Data strobe for upper byte: Output with read data, input with write data for source
synchronous operation. Edge-aligned with read data, center-aligned with write data.
UDQS# is only used when differential data strobe mode is enabled via the LOAD MODE
command.
RDQS, RDQS#
Output
Redundant data strobe: For x8 only. RDQS is enabled/disabled via the LOAD MODE command to the extended mode register (EMR). When RDQS is enabled, RDQS is output with
read data only and is ignored during write data. When RDQS is disabled, ball B3 becomes
data mask (see DM ball). RDQS# is only used when RDQS is enabled and differential data
strobe mode is enabled.
VDD
Supply
Power supply: 1.55V, -0.05V, +0.35V.
VDDQ
Supply
DQ power supply: 1.55V, -0.05V, +0.35V. Isolated on the device for improved noise immunity.
VDDL
Supply
DLL power supply: 1.55V, -0.05V, +0.35V.
VREF
Supply
SSTL_18 reference voltage.
VSS
Supply
Ground.
VSSDL
Supply
DLL ground: Isolated on the device from VSS and VSSQ.
VSSQ
Supply
DQ ground: Isolated on the device for improved noise immunity.
NC
–
No connect: These balls should be left unconnected.
NF
–
No function: Not used only on x4. These are data lines on the x8.
NU
–
Not used: Not used only on x16. If EMR[E10] = 0, A8 and E8 are UDQS# and LDQS#. If
EMR[E10] = 1, then A8 and E8 are not used.
NU
–
Not used: For x4: Not used. For x8: If EMR[E10] = 0, E2 and E8 are RDQS# and DQS#; if
EMR[E10] = 1, then E2 and E8 are not used.
RFU
–
Reserved for future use: Row address bits A14 (R3), A15 (R7) on the x16, and A15 (L7)
on the x4/x8.
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© 2011 Micron Technology, Inc. All rights reserved.
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Packaging
Packaging
Package Dimensions
Figure 8: 84-Ball FBGA Package (9mm x 12.5mm) – x16
0.8 ±0.05
0.155
Seating
plane
A
0.12 A
1.8 CTR
Nonconductive overmold
84X Ø0.45
Solder ball material:
SAC305 (96.5% Sn,
3% Ag, 0.5% Cu).
Dimensions apply to
solder balls post-reflow
9 8 7
on Ø0.35 SMD ball
pads.
Ball A1 ID
3
2
Ball A1 ID
1
A
B
C
D
E
F
G
H
11.2 CTR
12.5 ±0.1
J
K
L
M
N
P
0.8 TYP
R
0.8 TYP
1.2 MAX
6.4 CTR
0.25 MIN
9 ±0.1
Notes:
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
1. All dimensions are in millimeters.
2. Solder ball material: SAC305 (96.5% Sn, 3% Ag, 0.5% Cu) or leaded Eutectic (62% Sn,
36%Pb, 2% Ag).
18
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Packaging
Figure 9: 60-Ball FBGA Package (9mm x 11.5mm) – x4, x8
0.8 ±0.05
0.155
Seating
plane
1.8 CTR
A
0.12 A
60X Ø0.45
Solder ball material:
SAC305 (96.5% Sn,
3% Ag, 0.5% Cu).
Dimensions apply to
solder balls postreflow on Ø0.35
SMD ball pads.
9 8 7
Ball A1 ID
3 2 1
Ball A1 ID
A
B
C
D
E
8 CTR
F
11.5 ±0.1
G
H
J
K
0.8 TYP
L
1.2 MAX
0.8 TYP
0.25 MIN
6.4 CTR
9 ±0.1
Note:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
1. All dimensions are in millimeters.
19
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Packaging
FBGA Package Capacitance
Table 4: Input Capacitance
Parameter
Symbol
Min
Max
Units
Notes
Input capacitance: CK, CK#
CCK
1.0
2.0
pF
1
Delta input capacitance: CK, CK#
CDCK
–
0.25
pF
2, 3
Input capacitance: BA[2:0], A[14:0] (A[13:0] on
x16), CS#, RAS#, CAS#, WE#, CKE, ODT
CI
1.0
2.0
pF
1
Delta input capacitance: Address balls, bank
address balls, CS#, RAS#, CAS#, WE#, CKE, ODT
CDI
–
0.25
pF
2, 3
Input/output capacitance: DQ, DQS, DM, NF
CIO
2.5
4.0
pF
1, 4
Delta input/output capacitance: DQ, DQS, DM,
NF
CDIO
–
0.5
pF
2, 3
Notes:
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
1. This parameter is sampled. VDD = +1.8V ±0.1V, VDDQ = +1.8V ±0.1V, VREF = VSS, f = 100
MHz, TC = 25°C, VOUT(DC) = VDDQ/2, VOUT (peak-to-peak) = 0.1V. DM input is grouped
with I/O balls, reflecting the fact that they are matched in loading.
2. The capacitance per ball group will not differ by more than this maximum amount for
any given device.
3. ΔC are not pass/fail parameters; they are targets.
4. Reduce MAX limit by 0.25pF for -3/-3E speed devices.
20
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Electrical Specifications – Absolute Ratings
Electrical Specifications – Absolute Ratings
Stresses greater than those listed may cause permanent damage to the device. This is a
stress rating only, and functional operation of the device at these or any other conditions outside those indicated in the operational sections of this specification is not
implied. Exposure to absolute maximum rating conditions for extended periods may
affect reliability.
Table 5: Absolute Maximum DC Ratings
Parameter
Symbol
Min
Max
Units
Notes
VDD supply voltage relative to VSS
VDD
–1.0
2.3
V
1
VDDQ supply voltage relative to VSSQ
VDDQ
–0.5
2.3
V
1, 2
VDDL supply voltage relative to VSSL
VDDL
–0.5
2.3
V
1
Voltage on any ball relative to VSS
VIN, VOUT
–0.5
2.3
V
3
II
–5
5
µA
IOZ
–5
5
µA
IVREF
–2
2
µA
Input leakage current; any input 0V ≤ VIN ≤
VDD; all other balls not under test = 0V)
Output leakage current; 0V ≤ VOUT ≤ VDDQ; DQ
and ODT disabled
VREF leakage current; VREF = valid VREF level
Notes:
1. VDD, VDDQ, and VDDL must be within 300mV of each other at all times; this is not required when power is ramping down.
2. VREF ≤ 0.6 x VDDQ; however, VREF may be ≥ VDDQ provided that VREF ≤ 300mV.
3. Voltage on any I/O may not exceed voltage on VDDQ.
Temperature and Thermal Impedance
It is imperative that the DDR2 SDRAM device’s temperature specifications, shown in
Table 6 (page 22), be maintained in order to ensure the junction temperature is in the
proper operating range to meet data sheet specifications. An important step in maintaining the proper junction temperature is using the device’s thermal impedances correctly. The thermal impedances are listed in Table 7 (page 23) for the applicable and
available die revision and packages.
Incorrectly using thermal impedances can produce significant errors. Read Micron technical note TN-00-08, “Thermal Applications,” prior to using the thermal impedances
listed in Table 7. For designs that are expected to last several years and require the flexibility to use several designs, consider using final target theta values, rather than existing
values, to account for larger thermal impedances.
The DDR2 SDRAM device’s safe junction temperature range can be maintained when
the TC specification is not exceeded. In applications where the device’s ambient temperature is too high, use of forced air and/or heat sinks may be required in order to satisfy
the case temperature specifications.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Electrical Specifications – Absolute Ratings
Table 6: Temperature Limits
Parameter
Storage temperature
Symbol
Min
Max
Units
Notes
TSTG
–55
150
°C
1
Operating temperature – commercial
TC
0
85
°C
2, 3
Operating temperature – industrial
TC
–40
95
°C
2, 3, 4
TA
–40
85
°C
4, 5
Notes:
1. MAX storage case temperature TSTG is measured in the center of the package, as shown
in Figure 10. This case temperature limit is allowed to be exceeded briefly during package reflow, as noted in Micron technical note TN-00-15, “Recommended Soldering
Parameters.”
2. MAX operating case temperature TC is measured in the center of the package, as shown
in Figure 10.
3. Device functionality is not guaranteed if the device exceeds maximum TC during operation.
4. Both temperature specifications must be satisfied.
5. Operating ambient temperature surrounding the package.
Figure 10: Example Temperature Test Point Location
Test point
Length (L)
0.5 (L)
0.5 (W)
Width (W)
Lmm x Wmm FBGA
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Electrical Specifications – Absolute Ratings
Table 7: Thermal Impedance
Die Rev
C1
Package
Substrate
θ JA (°C/W)
Airflow = 0m/s
θ JA (°C/W)
Airflow = 1m/s
θ JA (°C/W)
Airflow = 2m/s
60-ball
2-layer
63.8
46.9
40.8
29.9
4-layer
46.9
38.1
34.4
29.2
2-layer
60.0
43.5
37.9
26.0
4-layer
43.2
34.7
31.5
25.5
84-ball
Note:
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
θ JB (°C/W) θ JC (°C/W)
4.3
4.1
1. Thermal resistance data is based on a number of samples from multiple lots and should
be viewed as a typical number.
23
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Electrical Specifications – IDD Parameters
Electrical Specifications – IDD Parameters
IDD Specifications and Conditions
Table 8: General IDD Parameters
IDD Parameters
CL (IDD)
tRCD
tRC
(IDD)
(IDD)
-187E
-25E
-25
-3E
-3
-37E
-5E
Units
7
5
6
4
5
4
3
tCK
13.125
12.5
15
12
15
15
15
ns
58.125
57.5
60
57
60
60
55
ns
tRRD
(IDD) - x4/x8 (1KB)
7.5
7.5
7.5
7.5
7.5
7.5
7.5
ns
tRRD
(IDD) - x16 (2KB)
10
10
10
10
10
10
10
ns
1.875
2.5
2.5
3
3
3.75
5
ns
tCK
(IDD)
tRAS
MIN (IDD)
45
45
45
45
45
45
40
ns
tRAS
MAX (IDD)
70,000
70,000
70,000
70,000
70,000
70,000
70,000
ns
13.125
12.5
15
12
15
15
15
ns
tRP
(IDD)
tRFC
(IDD - 256Mb)
75
75
75
75
75
75
75
ns
tRFC
(IDD - 512Mb)
105
105
105
105
105
105
105
ns
tRFC
(IDD - 1Gb)
127.5
127.5
127.5
127.5
127.5
127.5
127.5
ns
tRFC
(IDD - 2Gb)
197.5
197.5
197.5
197.5
197.5
197.5
197.5
ns
tFAW
(IDD) - x4/x8 (1KB)
Defined by pattern in Table 9 (page 25)
ns
tFAW
(IDD) - x16 (2KB)
Defined by pattern in Table 9 (page 25)
ns
IDD7 Conditions
The detailed timings are shown below for IDD7. Changes will be required if timing parameter changes are made to the specification. Where general IDD parameters in Table 8
conflict with pattern requirements of Table 9 (page 25), then Table 9 requirements
take precedence.
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
24
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© 2011 Micron Technology, Inc. All rights reserved.
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Electrical Specifications – IDD Parameters
Table 9: IDD7 Timing Patterns (8-Bank Interleave READ Operation)
Speed
Grade
IDD7 Timing Patterns
Timing patterns for 8-bank x4/x8 devices
-5E
A0 RA0 A1 RA1 A2 RA2 A3 RA3 A4 RA4 A5 RA5 A6 RA6 A7 RA7
-37E
A0 RA0 A1 RA1 A2 RA2 A3 RA3 D D A4 RA4 A5 RA5 A6 RA6 A7 RA7 D D
-3
A0 RA0 D A1 RA1 D A2 RA2 D A3 RA3 D D A4 RA4 D A5 RA5 D A6 RA6 D A7 RA7 D D
-3E
A0 RA0 D A1 RA1 D A2 RA2 D A3 RA3 D D A4 RA4 D A5 RA5 D A6 RA6 D A7 RA7 D D
-25
A0 RA0 D A1 RA1 D A2 RA2 D A3 RA3 D D D A4 RA4 D A5 RA5 D A6 RA6 D A7 RA7 D D D
-25E
A0 RA0 D A1 RA1 D A2 RA2 D A3 RA3 D D D A4 RA4 D A5 RA5 D A6 RA6 D A7 RA7 D D D
-187E
A0 RA0 D D A1 RA1 D D A2 RA2 D D A3 RA3 D D D D D A4 RA4 D D A5 RA5 D D A6 RA6 D D A7 RA7 D D D D D
Timing patterns for 8-bank x16 devices
-5E
A0 RA0 A1 RA1 A2 RA2 A3 RA3 D D A4 RA4 A5 RA5 A6 RA6 A7 RA7 D D
-37E
A0 RA0 D A1 RA1 D A2 RA2 D A3 RA3 D D D A4 RA4 D A5 RA5 D A6 RA6 D A7 RA7 D D D
-3
A0 RA0 D D A1 RA1 D D A2 RA2 D D A3 RA3 D D D A4 RA4 D D A5 RA5 D D A6 RA6 D D A7 RA7 D D D
-3E
A0 RA0 D D A1 RA1 D D A2 RA2 D D A3 RA3 D D D A4 RA4 D D A5 RA5 D D A6 RA6 D D A7 RA7 D D D
-25
A0 RA0 D D A1 RA1 D D A2 RA2 D D A3 RA3 D D D D A4 RA4 D D A5 RA5 D D A6 RA6 D D A7 RA7 D D D D
-25E
A0 RA0 D D A1 RA1 D D A2 RA2 D D A3 RA3 D D D D A4 RA4 D D A5 RA5 D D A6 RA6 D D A7 RA7 D D D D
-187E
A0 RA0 D D D D A1 RA1 D D D D A2 RA2 D D D D A3 RA3 D D D D A4 RA4 D D D D A5 RA5 D D D D A6 RA6 D
D D D A7 RA7 D D D D
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
1. A = active; RA = read auto precharge; D = deselect.
2. All banks are being interleaved at minimum tRC (IDD) without violating tRRD (IDD) using
a BL = 4.
3. Control and address bus inputs are STABLE during DESELECTs.
25
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© 2011 Micron Technology, Inc. All rights reserved.
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Electrical Specifications – IDD Parameters
Table 10: DDR2 IDD Specifications and Conditions
Notes 1–7 apply to the entire table
Parameter/Condition
Symbol
Configuration
Operating one bank active-precharge current:
tCK = tCK (I ), tRC = tRC (I ), tRAS = tRAS MIN (I ); CKE
DD
DD
DD
is HIGH, CS# is HIGH between valid commands; Address
bus inputs are switching; Data bus inputs are switching
IDD0
x4, x8
x16
Operating one bank active-read-precharge current:
Iout = 0mA; BL = 4, CL = CL (IDD), AL = 0; tCK = tCK (IDD),
tRC = tRC (I ), tRAS = tRAS MIN (I ), tRCD = tRCD (I );
DD
DD
DD
CKE is HIGH, CS# is HIGH between valid commands; Address bus inputs are switching; Data pattern is same as IDD4W
IDD1
x4, x8
95
90
x16
125
120
Precharge power-down current: All banks idle; tCK =
tCK (I ); CKE is LOW; Other control and address bus inDD
puts are stable; Data bus inputs are floating
IDD2P
x4, x8, x16
12
12
mA
Precharge quiet standby current: All banks idle; tCK =
tCK (I ); CKE is HIGH, CS# is HIGH; Other control and adDD
dress bus inputs are stable; Data bus inputs are floating
IDD2Q
x4, x8
35
30
mA
x16
50
45
Precharge standby current: All banks idle; tCK = tCK
(IDD); CKE is HIGH, CS# is HIGH; Other control and address
bus inputs are switching; Data bus inputs are switching
IDD2N
x4, x8
40
35
x16
55
50
Active power-down current: All banks open; tCK = tCK
(IDD); CKE is LOW; Other control and address bus inputs
are stable; Data bus inputs are floating
IDD3Pf
Fast PDN exit
MR[12] = 0
30
25
IDD3Ps
Slow PDN exit
MR[12] = 1
14
14
Active standby current: All banks open; tCK = tCK (IDD),
tRAS = tRAS MAX (I ), tRP = tRP (I ); CKE is HIGH, CS# is
DD
DD
HIGH between valid commands; Other control and address bus inputs are switching; Data bus inputs are switching
IDD3N
x4, x8
50
45
x16
70
65
Operating burst write current: All banks open, continuous burst writes; BL = 4, CL = CL (IDD), AL = 0; tCK = tCK
(IDD), tRAS = tRAS MAX (IDD), tRP = tRP (IDD); CKE is HIGH,
CS# is HIGH between valid commands; Address bus inputs
are switching; Data bus inputs are switching
IDD4W
x4, x8
150
130
x16
235
200
Operating burst read current: All banks open, continuous burst reads, IOUT = 0mA; BL = 4, CL = CL (IDD), AL = 0;
tCK = tCK (I ), tRAS = tRAS MAX (I ), tRP = tRP (I ); CKE
DD
DD
DD
is HIGH, CS# is HIGH between valid commands; Address
bus inputs are switching; Data bus inputs are switching
IDD4R
x4, x8
150
130
x16
235
200
Burst refresh current: tCK = tCK (IDD); refresh command
at every tRFC (IDD) interval; CKE is HIGH, CS# is HIGH between valid commands; Other control and address bus
inputs are switching; Data bus inputs are switching
IDD5
x4, x8
185
165
x16
220
200
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
26
-25E/-25
-3E/-3
Units
80
75
mA
115
110
mA
mA
mA
mA
mA
mA
mA
Micron Technology, Inc. reserves the right to change products or specifications without notice.
© 2011 Micron Technology, Inc. All rights reserved.
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Electrical Specifications – IDD Parameters
Table 10: DDR2 IDD Specifications and Conditions (Continued)
Notes 1–7 apply to the entire table
Parameter/Condition
Symbol
Configuration
-25E/-25
-3E/-3
Units
IDD6
x4, x8, x16
12
12
mA
8
8
x4, x8
250
225
x16
330
300
Self refresh current: CK and CK# at 0V; CKE ≤ 0.2V; Other control and address bus inputs are floating; Data bus
inputs are floating
IDD6L
Operating bank interleave read current: All bank interleaving reads, IOUT = 0mA; BL = 4, CL = CL (IDD), AL =
tRCD (I ) - 1 x tCK (I ); tCK = tCK (I ), tRC = tRC (I ),
DD
DD
DD
DD
tRRD = tRRD (I ), tRCD = tRCD (I ); CKE is HIGH, CS# is
DD
DD
HIGH between valid commands; Address bus inputs are stable during deselects; Data bus inputs are switching (see
Table 9 (page 25) for details)
Notes:
IDD7
mA
IDD specifications are tested after the device is properly initialized. 0°C ≤ TC ≤ +85°C.
VDD = +1.8V ±0.1V, VDDQ = +1.8V ±0.1V, VDDL = +1.8V ±0.1V, VREF = VDDQ/2.
IDD parameters are specified with ODT disabled.
Data bus consists of DQ, DM, DQS, DQS#, RDQS, RDQS#, LDQS, LDQS#, UDQS, and
UDQS#. IDD values must be met with all combinations of EMR bits 10 and 11.
5. Definitions for IDD conditions:
1.
2.
3.
4.
LOW
VIN ≤ VIL(AC)max
VIN ≥ VIH(AC)min
Inputs stable at a HIGH or LOW level
Stable
Inputs at VREF = VDDQ/2
Floating
Switching Inputs changing between HIGH and LOW every other clock cycle (once per
two clocks) for address and control signals
Switching Inputs changing between HIGH and LOW every other data transfer (once
per clock) for DQ signals, not including masks or strobes
6. IDD1, IDD4R, and IDD7 require A12 in EMR1 to be enabled during testing.
7. The following IDD values must be derated (IDD limits increase) on IT-option devices when
operated outside of the range 0°C ≤ TC ≤ 85°C:
HIGH
When
TC ≤ 0°C
When
TC ≥ 85°C
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
IDD2P and IDD3P(SLOW) must be derated by 4%; IDD4R and IDD5W
must be derated by 2%; and IDD6 and IDD7 must be derated by
7%.
IDD0, IDD1, IDD2N, IDD2Q, IDD3N, IDD3P(FAST), IDD4R, IDD4W, and IDD5W
must be derated by 2%; IDD2P must be derated by 20%; IDD3P
slow must be derated by 30%; and IDD6 must be derated by
80% (IDD6 will increase by this amount if TC < 85°C and the 2x
refresh option is still enabled).
27
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
AC Timing Operating Specifications
Table 11: AC Operating Specifications and Conditions
Not all speed grades listed may be supported for this device; refer to the title page for speeds supported; Notes: 1–5 apply to the entire table;
VDDQ = +1.5–1.9V, VDD = +1.5–1.9V
AC Characteristics
-25E
-25
-3E
-3
-37E
Parameter
Min
Max
Min
Max
(avg)
2.5
8.0
2.5
8.0
–
–
(avg)
2.5
8.0
3.0
8.0
3.0
8.0
tCK
(avg)
3.75
8.0
3.75
8.0
3.0
8.0
3.75
tCK
(avg)
5.0
8.0
5.0
8.0
5.0
8.0
5.0
8.0
5.0
8.0
CK high-level width
tCH
(avg)
0.48
0.52
0.48
0.52
0.48
0.52
0.48
0.52
0.48
CK low-level width
tCL
Clock
Clock
cycle time
Symbol
CL = 6
tCK
CL = 5
tCK
CL = 4
CL = 3
Half clock period
0.48
0.52
0.48
0.52
0.48
Max
0.52
tCH
MIN = lesser of
and
MAX = n/a
Min
Max
Min
Max
Units
Notes
–
–
–
–
ns
6, 7, 8, 9
3.0
8.0
–
–
8.0
3.75
8.0
0.52
tCK
10
0.52
tCK
0.48
0.52
0.48
tCL
ps
28
tCK
(abs)
MIN = tCK (AVG) MIN + tJITper (MIN)
MAX = tCK (AVG) MAX + tJITper (MAX)
ps
Absolute CK
high-level width
tCH
(abs)
MIN = tCK (AVG) MIN × tCH (AVG) MIN + tJITdty (MIN)
MAX = tCK (AVG) MAX × tCH (AVG) MAX + tJITdty (MAX)
ps
Absolute CK
low-level width
tCL
(abs)
MIN = tCK (AVG) MIN × tCL (AVG) MIN + tJITdty (MIN)
MAX = tCK (AVG) MAX × tCL (AVG) MAX + tJITdty (MAX)
ps
11
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© 2011 Micron Technology, Inc. All rights reserved.
Period jitter
tJITper
–100
100
–100
100
–125
125
–125
125
–125
125
ps
12
Half period
tJITdty
–100
100
–100
100
–125
125
–125
125
–125
125
ps
13
tJITcc
200
ps
14
200
250
250
250
Cumulative error,
2 cycles
tERR
–150
150
–150
150
–175
175
–175
175
–175
175
ps
15
Cumulative error,
3 cycles
tERR
–175
175
–175
175
–225
225
–225
225
–225
225
ps
15
Cumulative error,
4 cycles
tERR
–200
200
–200
200
–250
250
–250
250
–250
250
ps
15
Cumulative error,
5 cycles
tERR
5per
–200
200
–200
200
–250
250
–250
250
–250
250
ps
15, 16
2per
3per
4per
Cumulative error,
6–10 cycles
tERR
6–10per
–300
300
–300
300
–350
350
–350
350
–350
350
ps
15, 16
Cumulative error,
11–50 cycles
tERR
11–50per
–450
450
–450
450
–450
450
–450
450
–450
450
ps
15
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
AC Timing Operating Specifications
Absolute tCK
Cycle to cycle
Clock Jitter
(avg)
tHP
Min
Not all speed grades listed may be supported for this device; refer to the title page for speeds supported; Notes: 1–5 apply to the entire table;
VDDQ = +1.5–1.9V, VDD = +1.5–1.9V
AC Characteristics
-25E
-25
-3E
-3
-37E
Parameter
Data Strobe-Out
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Table 11: AC Operating Specifications and Conditions (Continued)
29
Symbol
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Units
Notes
tDQSCK
–350
+350
–350
+350
–400
+400
–400
+400
–450
+450
ps
19
DQS read preamble
tRPRE
MIN = 0.9 × tCK
MAX = 1.1 × tCK
tCK
17, 18, 19
DQS read postamble
tRPST
MIN = 0.4 × tCK
MAX = 0.6 × tCK
tCK
17, 18,
19, 20
tLZ
MIN = tAC (MIN)
MAX = tAC (MAX)
ps
19, 21, 22
DQS rising edge to CK
rising edge
tDQSS
MIN = –0.25 × tCK
MAX = +0.25 × tCK
tCK
18
DQS input-high pulse
width
tDQSH
MIN = 0.35 × tCK
MAX = n/a
tCK
18
DQS input-low pulse
width
tDQSL
MIN = 0.35 × tCK
MAX = n/a
tCK
18
DQS falling to CK
rising: setup time
tDSS
MIN = 0.2 × tCK
MAX = n/a
tCK
18
DQS falling from CK
rising: hold time
tDSH
MIN = 0.2 × tCK
MAX = n/a
tCK
18
tWPRES
MIN = 0
MAX = n/a
ps
23, 24
DQS write preamble
tWPRE
MIN = 0.35 × tCK
MAX = n/a
tCK
18
DQS write postamble
tWPST
MIN = 0.4 × tCK
MAX = 0.6 × tCK
tCK
18, 25
–
MIN = WL - tDQSS
MAX = WL + tDQSS
tCK
CK/CK# to DQS
Low-Z
Write preamble setup
time
WRITE command to first
DQS transition
1
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
AC Timing Operating Specifications
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© 2011 Micron Technology, Inc. All rights reserved.
Data Strobe-In
DQS output access time
from CK/CK#
Not all speed grades listed may be supported for this device; refer to the title page for speeds supported; Notes: 1–5 apply to the entire table;
VDDQ = +1.5–1.9V, VDD = +1.5–1.9V
AC Characteristics
-25E
-25
-3E
-3
-37E
Parameter
Data-Out
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Table 11: AC Operating Specifications and Conditions (Continued)
Symbol
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Units
Notes
DQ output access time
from CK/CK#
tAC
–400
+400
–400
+400
–450
+450
–450
+450
–500
+500
ps
19
DQS–DQ skew, DQS to
last DQ valid,
per group,
per access
tDQSQ
–
200
–
200
–
240
–
240
–
300
ps
26, 27
tQHS
–
300
–
300
–
340
–
340
–
400
ps
28
DQ hold from next DQS
strobe
tQH
MIN = tHP - tQHS
MAX = n/a
ps
26, 27, 28
CK/CK# to DQ, DQS
High-Z
tHZ
MIN = n/a
MAX = tAC (MAX)
ps
19, 21, 29
CK/CK# to DQ Low-Z
tLZ
MIN = 2 × tAC (MIN)
MAX = tAC (MAX)
ps
19, 21, 22
Data valid output
window
DVW
MIN = tQH - tDQSQ
MAX = n/a
ns
26, 27
DQ and DM input setup
time to DQS
tDSb
50
–
50
–
100
–
100
–
100
–
ps
26, 30, 31
DQ and DM input hold
time to DQS
tDHb
125
–
125
–
175
–
175
–
225
–
ps
26, 30, 31
DQ and DM input setup
time to DQS
tDSa
250
–
250
–
300
–
300
–
350
–
ps
26, 30, 31
DQ and DM input hold
time to DQS
tDHa
250
–
250
–
300
–
300
–
350
–
ps
26, 30, 31
DQ and DM input pulse
width
tDIPW
tCK
18, 32
2
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© 2011 Micron Technology, Inc. All rights reserved.
Data-In
30
MIN = 0.35 × tCK
MAX = n/a
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
AC Timing Operating Specifications
DQ–DQS hold, DQS to
first DQ not valid
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Table 11: AC Operating Specifications and Conditions (Continued)
Not all speed grades listed may be supported for this device; refer to the title page for speeds supported; Notes: 1–5 apply to the entire table;
VDDQ = +1.5–1.9V, VDD = +1.5–1.9V
AC Characteristics
-25E
-25
-3E
-3
-37E
Symbol
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Units
Notes
Input setup time
Parameter
tISb
175
–
175
–
200
–
200
–
250
–
ps
31, 33
Input hold time
tIHb
250
–
250
–
275
–
275
–
375
–
ps
31, 33
Input setup time
tISa
375
–
375
–
400
–
400
–
500
–
ps
31, 33
Input hold time
tIHa
375
–
375
–
400
–
400
–
500
–
ps
31, 33
Input pulse width
tIPW
0.6
–
0.6
–
0.6
–
0.6
–
0.6
–
tCK
18, 32
tRC
55
–
55
–
54
–
55
–
55
–
ns
18, 34
ACTIVATE-to-READ or
WRITE delay
tRCD
12.5
–
15
–
12
–
15
–
15
–
ns
18
ACTIVATE-to- PRECHARGE delay
tRAS
40
70K
40
70K
40
70K
40
70K
40
70K
ns
18, 34, 35
tRP
12.5
–
15
–
12
–
15
–
15
–
ns
18, 36
–
12
–
15
–
15
–
ns
18, 36
31
PRECHARGE period
PRECHARGE
ALL period
1, such as frequencies faster than
533 MHz when tRTP = 7.5ns. If tRTP/(2 × tCK) ≤ 1, then equation AL + BL/2 applies. tRAS
(MIN) has to be satisfied as well. The DDR2 SDRAM will automatically delay the internal
PRECHARGE command until tRAS (MIN) has been satisfied.
tDAL = (nWR) + (tRP/tCK). Each of these terms, if not already an integer, should be rounded up to the next integer. tCK refers to the application clock period; nWR refers to the
tWR parameter stored in the MR9–MR11. For example, -37E at tCK = 3.75ns with tWR
programmed to four clocks would have tDAL = 4 + (15ns/3.75ns) clocks = 4 + (4) clocks =
8 clocks.
The refresh period is 64ms (commercial) or 32ms (industrial and automotive). This equates to an average refresh rate of 7.8125µs (commercial) or 3.9607µs (industrial and
automotive). To ensure all rows of all banks are properly refreshed, 8,192 REFRESH commands must be issued every 64ms (commercial) or 32ms (industrial and automotive). The
JEDEC tRFC MAX of 70,000ns is not required as bursting of AUTO REFRESH commands is
allowed.
tDELAY is calculated from tIS + tCK + tIH so that CKE registration LOW is guaranteed prior to CK, CK# being removed in a system RESET condition (see Reset (page 119)).
tISXR is equal to tIS and is used for CKE setup time during self refresh exit, as shown in
Figure 67 (page 110).
tCKE (MIN) of three clocks means CKE must be registered on three consecutive positive
clock edges. CKE must remain at the valid input level the entire time it takes to achieve
the three clocks of registration. Thus, after any CKE transition, CKE may not transition
from its valid level during the time period of tIS + 2 × tCK + tIH.
The half-clock of tAOFD’s 2.5 tCK assumes a 50/50 clock duty cycle. This half-clock value
must be derated by the amount of half-clock duty cycle error. For example, if the clock
36
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
AC and DC Operating Conditions
46.
47.
48.
49.
50.
duty cycle was 47/53, tAOFD would actually be 2.5 - 0.03, or 2.47, for tAOF (MIN) and 2.5
+ 0.03, or 2.53, for tAOF (MAX).
ODT turn-on time tAON (MIN) is when the device leaves High-Z and ODT resistance begins to turn on. ODT turn-on time tAON (MAX) is when the ODT resistance is fully on.
Both are measured from tAOND.
ODT turn-off time tAOF (MIN) is when the device starts to turn off ODT resistance. ODT
turn off time tAOF (MAX) is when the bus is in High-Z. Both are measured from tAOFD.
Half-clock output parameters must be derated by the actual tERR5per and tJITdty when
input clock jitter is present; this will result in each parameter becoming larger. The parameter tAOF (MIN) is required to be derated by subtracting both tERR5per (MAX) and
tJITdty (MAX). The parameter tAOF (MAX) is required to be derated by subtracting both
tERR
t
5perx (MIN) and JITdty (MIN).
The -187E maximum limit is 2 × tCK + tAC (MAX) + 1,000 but it will likely be
3 x tCK + tAC (MAX) + 1,000 in the future.
Should use 8 tCK for backward compatibility.
AC and DC Operating Conditions
Table 12: Recommended DC Operating Conditions (SSTL_18)
All voltages referenced to VSS
Parameter
Symbol
Min
Nom
Max
Units
Notes
VDD
1.5
1.55
1.9
V
1, 2
VDDL supply voltage
VDDL
1.5
1.55
1.9
V
2, 3
I/O supply voltage
VDDQ
1.5
1.55
1.9
V
2, 3
VREF(DC)
0.49 × VDDQ
0.50 × VDDQ
0.51 × VDDQ
V
4
VTT
VREF(DC) - 40
VREF(DC)
VREF(DC) + 40
mV
5
Supply voltage
I/O reference voltage
I/O termination voltage (system)
Notes:
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1. VDD and VDDQ must track each other. If VDD < 1.7V, then VDD - 0.05V ≤ VDDQ ≤ VDD; else
VDD - 0.1V ≤ VDDQ ≤ VDD.
2. VSSQ = VSSL = VSS.
3. VDDQ tracks with VDD; VDDL tracks with VDD.
4. VREF is expected to equal VDDQ/2 of the transmitting device and to track variations in the
DC level of the same. Peak-to-peak noise (noncommon mode) on VREF may not exceed
±1% of the DC value. Peak-to-peak AC noise on VREF may not exceed ±2% of VREF(DC).
This measurement is to be taken at the nearest VREF bypass capacitor.
5. VTT is not applied directly to the device. VTT is a system supply for signal termination
resistors, is expected to be set equal to VREF, and must track variations in the DC level of
VREF.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
ODT DC Electrical Characteristics
ODT DC Electrical Characteristics
Table 13: ODT DC Electrical Characteristics
All voltages are referenced to VSS; 1.55V DDR2 SDRAM has NOM and MAX limit increase by 8% when VDD is less than 1.7V.
VDD = +1.5V to +1.9V, VDDQ = +1.5V to +1.9V. If VDD < 1.7V then VDD - 0.05V ≤ VDDQ ≤ VDD; else VDD - 0.1V ≤ VDDQ ≤ VDD.
Voltage
Parameter
Symbol
Min
Min
Nom
Max
Units
Notes
RTT effective impedance value for 75Ω setting
EMR (A6, A2) = 0, 1
RTT1(EFF)
RTT effective impedance value for 150Ω setting
EMR (A6, A2) = 1, 0
RTT2(EFF)
RTT effective impedance value for 50Ω setting
EMR (A6, A2) = 1, 1
RTT3(EFF)
Deviation of VM with respect to VDDQ/2
Notes:
ΔVM
1.7V
60
75
90
Ω
1.5V
60
80
98
Ω
1.7V
120
150
180
Ω
1.5V
120
160
195
Ω
1.7V
40
50
60
Ω
1.5V
40
55
65
Ω
–
–6
–
6
%
1, 2
1, 2
1, 2
3
1. RTT1(EFF) and RTT2(EFF) are determined by separately applying VIH(AC) and VIL(DC) to the ball
being tested, and then measuring current, I(VIH[AC]), and I(VIL[AC]), respectively.
2. Minimum IT and AT device values are derated by six percent when the devices operate
between –40°C and 0°C (TC ).
3. Measure voltage (VM) at tested ball with no load.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Input Electrical Characteristics and Operating Conditions
Input Electrical Characteristics and Operating Conditions
Table 14: Input DC Logic Levels
All voltages are referenced to VSS
Parameter
Symbol
Min
Max
Units
1
Input high (logic 1) voltage
VIH(DC)
VREF(DC) + 125
VDDQ
mV
Input low (logic 0) voltage
VIL(DC)
–300
VREF(DC) - 125
mV
Note:
1. VDDQ + 300mV allowed provided 1.9V is not exceeded.
Table 15: Input AC Logic Levels
All voltages are referenced to VSS
Parameter
Symbol
Input high (logic 1) voltage (-37E/-5E)
VIH(AC)
Min
Max
VREF(DC) + 250
Units
1
mV
1
VDDQ
Input high (logic 1) voltage (-187E/-25E/-25/-3E/-3)
VIH(AC)
VREF(DC) + 200
VDDQ
mV
Input low (logic 0) voltage (-37E/-5E)
VIL(AC)
–300
VREF(DC) - 250
mV
Input low (logic 0) voltage (-187E/-25E/-25/-3E/-3)
VIL(AC)
–300
VREF(DC) - 200
mV
Note:
1. Refer to AC Overshoot/Undershoot Specification (page 49).
Figure 11: Single-Ended Input Signal Levels
1,150mV
VIH(AC)
1,025mV
VIH(DC)
Note:
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936mV
918mV
900mV
882mV
864mV
VREF + AC noise
VREF + DC error
VREF - DC error
VREF - AC noise
775mV
VIL(DC)
650mV
VIL(AC)
1. Numbers in diagram reflect nominal DDR2-400/DDR2-533 values.
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Input Electrical Characteristics and Operating Conditions
Table 16: Differential Input Logic Levels
All voltages referenced to VSS
Parameter
Symbol
Min
Max
Units
Notes
DC input signal voltage
VIN(DC)
–300
VDDQ
mV
1, 6
DC differential input voltage
VID(DC)
250
VDDQ
mV
2, 6
AC differential input voltage
VID(AC)
500
VDDQ
mV
3, 6
AC differential cross-point voltage
VIX(AC)
0.50 × VDDQ - 175
0.50 × VDDQ + 175
mV
4
Input midpoint voltage
VMP(DC)
850
950
mV
5
Notes:
1. VIN(DC) specifies the allowable DC execution of each input of differential pair such as CK,
CK#, DQS, DQS#, LDQS, LDQS#, UDQS, UDQS#, and RDQS, RDQS#.
2. VID(DC) specifies the input differential voltage |VTR - VCP| required for switching, where
VTR is the true input (such as CK, DQS, LDQS, UDQS) level and VCP is the complementary
input (such as CK#, DQS#, LDQS#, UDQS#) level. The minimum value is equal to VIH(DC) VIL(DC). Differential input signal levels are shown in Figure 12.
3. VID(AC) specifies the input differential voltage |VTR - VCP| required for switching, where
VTR is the true input (such as CK, DQS, LDQS, UDQS, RDQS) level and VCP is the complementary input (such as CK#, DQS#, LDQS#, UDQS#, RDQS#) level. The minimum value is
equal to VIH(AC) - VIL(AC), as shown in Table 15 (page 39).
4. The typical value of VIX(AC) is expected to be about 0.5 × VDDQ of the transmitting device
and VIX(AC) is expected to track variations in VDDQ. VIX(AC) indicates the voltage at which
differential input signals must cross, as shown in Figure 12.
5. VMP(DC) specifies the input differential common mode voltage (VTR + VCP)/2 where VTR is
the true input (CK, DQS) level and VCP is the complementary input (CK#, DQS#). VMP(DC)
is expected to be approximately 0.5 × VDDQ.
6. VDDQ + 300mV allowed provided 1.9V is not exceeded.
Figure 12: Differential Input Signal Levels
VIN(DC)max1
2.1V
VDDQ = 1.8V
CP2
1.075V
X
VMP(DC)3
0.9V
0.725V
VIX(AC)4
VID(DC)5
VID(AC)6
X
TR2
VIN(DC)min1
–0.30V
Notes:
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1. TR and CP may not be more positive than VDDQ + 0.3V or more negative than VSS - 0.3V.
2. TR represents the CK, DQS, RDQS, LDQS, and UDQS signals; CP represents CK#, DQS#,
RDQS#, LDQS#, and UDQS# signals.
3. This provides a minimum of 850mV to a maximum of 950mV and is expected to be
VDDQ/2.
4. TR and CP must cross in this region.
5. TR and CP must meet at least VID(DC)min when static and is centered around VMP(DC).
6. TR and CP must have a minimum 500mV peak-to-peak swing.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Input Electrical Characteristics and Operating Conditions
7. Numbers in diagram reflect nominal values (VDDQ = 1.8V).
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Output Electrical Characteristics and Operating Conditions
Output Electrical Characteristics and Operating Conditions
Table 17: Differential AC Output Parameters
Parameter
Symbol
Min
Max
Units
Notes
AC differential cross-point voltage
VOX(AC)
0.50 × VDDQ - 125
0.50 × VDDQ + 125
mV
1
AC differential voltage swing
Vswing
1.0
–
mV
Note:
1. The typical value of VOX(AC) is expected to be about 0.5 × VDDQ of the transmitting device and VOX(AC) is expected to track variations in VDDQ. VOX(AC) indicates the voltage at
which differential output signals must cross.
Figure 13: Differential Output Signal Levels
VDDQ
VTR
Crossing point
Vswing
VOX
VCP
VSSQ
Table 18: Output DC Current Drive
Parameter
Symbol
Value
Units
Notes
Output MIN source DC current
IOH
–13.4
mA
1, 2, 4
Output MIN sink DC current
IOL
13.4
mA
2, 3, 4
Notes:
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1. For IOH(DC); VDDQ = 1.7V, VOUT = 1,420mV. (VOUT - VDDQ)/IOH must be less than 21Ω for
values of VOUT between VDDQ and VDDQ - 280mV.
2. For IOL(DC); VDDQ = 1.7V, VOUT = 280mV. VOUT/IOL must be less than 21Ω for values of VOUT
between 0V and 280mV.
3. The DC value of VREF applied to the receiving device is set to VTT.
4. The values of IOH(DC) and IOL(DC) are based on the conditions given in Notes 1 and 2. They
are used to test device drive current capability to ensure VIHmin plus a noise margin and
VILmax minus a noise margin are delivered to an SSTL_18 receiver. The actual current values are derived by shifting the desired driver operating point (see output IV curves)
along a 21Ω load line to define a convenient driver current for measurement.
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Output Electrical Characteristics and Operating Conditions
Table 19: Output Characteristics
Parameter
Min
Output impedance
Max
See Output Driver Characteristics (page 44)
Units
Notes
Ω
1, 2
0
–
4
Ω
1, 2, 3
VDDmin = 1.7V
1.5
–
7
V/ns
4, 5, 6, 7
VDDmin = 1.5V
0.8
–
7
V/ns
4, 5, 6, 7
Pull-up and pull-down mismatch
Output slew
rate
Nom
Notes:
1. Absolute specifications: 0°C ≤ TC ≤ +85°C; VDDQ = +1.8V ±0.1V, VDD = +1.8V ±0.1V.
2. Impedance measurement conditions for output source DC current: VDDQ = 1.7V;
VOUT = 1,420mV; (VOUT - VDDQ)/IOH must be less than 23.4Ω for values of VOUT between
VDDQ and VDDQ - 280mV. The impedance measurement condition for output sink DC current: VDDQ = 1.7V; VOUT = 280mV; VOUT/IOL must be less than 23.4Ω for values of VOUT
between 0V and 280mV.
3. Mismatch is an absolute value between pull-up and pull-down; both are measured at
the same temperature and voltage.
4. Output slew rate for falling and rising edges is measured between VTT - 250mV and
VTT + 250mV for single-ended signals. For differential signals (DQS, DQS#), output slew
rate is measured between DQS - DQS# = –500mV and DQS# - DQS = +500mV. Output
slew rate is guaranteed by design but is not necessarily tested on each device.
5. The absolute value of the slew rate as measured from VIL(DC)max to VIH(DC)min is equal to
or greater than the slew rate as measured from VIL(AC)max to VIH(AC)min. This is guaranteed by design and characterization.
6. IT and AT devices require an additional 0.4 V/ns in the MAX limit when TC is between –
40°C and 0°C.
7. The output impedance drive curves MIN limit requires a 10% reduction when VDD is between 1.7V and 1.5V.
Figure 14: Output Slew Rate Load
VTT = VDDQ/2
Output
(VOUT)
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25Ω
Reference
point
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Output Driver Characteristics
Output Driver Characteristics
Figure 15: Full Strength Pull-Down Characteristics
120
100
IOUT (mA)
80
60
40
20
0
0.0
0.5
1.0
1.5
VOUT (V)
Table 20: Full Strength Pull-Down Current (mA)
Voltage (V)
Min
Nom
Max
0.0
0.00
0.00
0.00
0.1
4.30
5.63
7.95
0.2
8.60
11.30
15.90
0.3
12.90
16.52
23.85
0.4
16.90
22.19
31.80
0.5
20.40
27.59
39.75
0.6
23.28
32.39
47.70
0.7
25.44
36.45
55.55
0.8
26.79
40.38
62.95
0.9
27.67
44.01
69.55
1.0
28.38
47.01
75.35
1.1
28.96
49.63
80.35
1.2
29.46
51.71
84.55
1.3
29.90
53.32
87.95
1.4
30.29
54.9
90.70
1.5
30.65
56.03
93.00
1.6
30.98
57.07
95.05
1.7
31.31
58.16
97.05
1.8
31.64
59.27
99.05
1.9
31.96
60.35
101.05
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Output Driver Characteristics
Figure 16: Full Strength Pull-Up Characteristics
0
–20
IOUT (mA)
–40
–60
–80
–100
–120
0
0.5
1.0
1.5
VDDQ - VOUT (V)
Table 21: Full Strength Pull-Up Current (mA)
Voltage (V)
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Min
Nom
Max
0.0
0.00
0.00
0.00
0.1
–4.30
–5.63
–7.95
0.2
–8.60
–11.30
–15.90
0.3
–12.90
–16.52
–23.85
0.4
–16.90
–22.19
–31.80
0.5
–20.40
–27.59
–39.75
0.6
–23.28
–32.39
–47.70
0.7
–25.44
–36.45
–55.55
0.8
–26.79
–40.38
–62.95
0.9
–27.67
–44.01
–69.55
1.0
–28.38
–47.01
–75.35
1.1
–28.96
–49.63
–80.35
1.2
–29.46
–51.71
–84.55
1.3
–29.90
–53.32
–87.95
1.4
–30.29
–54.90
–90.70
1.5
–30.65
–56.03
–93.00
1.6
–30.98
–57.07
–95.05
1.7
–31.31
–58.16
–97.05
1.8
–31.64
–59.27
–99.05
1.9
–31.96
–60.35
–101.05
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Output Driver Characteristics
Figure 17: Reduced Strength Pull-Down Characteristics
70
60
IOUT (mV)
50
40
30
20
10
0
0.0
0.5
1.0
1.5
VOUT (V)
Table 22: Reduced Strength Pull-Down Current (mA)
Voltage (V)
Min
Nom
Max
0.0
0.00
0.00
0.00
0.1
1.72
2.98
4.77
0.2
3.44
5.99
9.54
0.3
5.16
8.75
14.31
0.4
6.76
11.76
19.08
0.5
8.16
14.62
23.85
0.6
9.31
17.17
28.62
0.7
10.18
19.32
33.33
0.8
10.72
21.40
37.77
0.9
11.07
23.32
41.73
1.0
11.35
24.92
45.21
1.1
11.58
26.30
48.21
1.2
11.78
27.41
50.73
1.3
11.96
28.26
52.77
1.4
12.12
29.10
54.42
1.5
12.26
29.70
55.80
1.6
12.39
30.25
57.03
1.7
12.52
30.82
58.23
1.8
12.66
31.41
59.43
1.9
12.78
31.98
60.63
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Output Driver Characteristics
Figure 18: Reduced Strength Pull-Up Characteristics
0
–10
IOUT (mV)
–20
–30
–40
–50
–60
–70
0.0
0.5
1.0
1.5
VDDQ - VOUT (V)
Table 23: Reduced Strength Pull-Up Current (mA)
Voltage (V)
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Min
Nom
Max
0.0
0.00
0.00
0.00
0.1
–1.72
–2.98
–4.77
0.2
–3.44
–5.99
–9.54
0.3
–5.16
–8.75
–14.31
0.4
–6.76
–11.76
–19.08
0.5
–8.16
–14.62
–23.85
0.6
–9.31
–17.17
–28.62
0.7
–10.18
–19.32
–33.33
0.8
–10.72
–21.40
–37.77
0.9
–11.07
–23.32
–41.73
1.0
–11.35
–24.92
–45.21
1.1
–11.58
–26.30
–48.21
1.2
–11.78
–27.41
–50.73
1.3
–11.96
–28.26
–52.77
1.4
–12.12
–29.10
–54.42
1.5
–12.26
–29.69
–55.8
1.6
–12.39
–30.25
–57.03
1.7
–12.52
–30.82
–58.23
1.8
–12.66
–31.42
–59.43
1.9
–12.78
–31.98
–60.63
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Power and Ground Clamp Characteristics
Power and Ground Clamp Characteristics
Power and ground clamps are provided on the following input-only balls: Address balls,
bank address balls, CS#, RAS#, CAS#, WE#, ODT, and CKE.
Table 24: Input Clamp Characteristics
Voltage Across Clamp (V)
Minimum Power Clamp Current
(mA)
Minimum Ground Clamp Current
(mA)
0.0
0.0
0.0
0.1
0.0
0.0
0.2
0.0
0.0
0.3
0.0
0.0
0.4
0.0
0.0
0.5
0.0
0.0
0.6
0.0
0.0
0.7
0.0
0.0
0.8
0.1
0.1
0.9
1.0
1.0
1.0
2.5
2.5
1.1
4.7
4.7
1.2
6.8
6.8
1.3
9.1
9.1
1.4
11.0
11.0
1.5
13.5
13.5
1.6
16.0
16.0
1.7
18.2
18.2
1.8
21.0
21.0
Figure 19: Input Clamp Characteristics
Minimum Clamp Current (mA)
25
20
15
10
5
0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8
Voltage Across Clamp (V)
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AC Overshoot/Undershoot Specification
AC Overshoot/Undershoot Specification
Some revisions will support the 0.9V maximum average amplitude instead of the 0.5V
maximum average amplitude shown in Table 25 and Table 26.
Table 25: Address and Control Balls
Applies to address balls, bank address balls, CS#, RAS#, CAS#, WE#, CKE, and ODT
Specification
Parameter
-187E
-25/-25E
-3/-3E
-37E
-5E
Maximum peak amplitude allowed for overshoot area
(see Figure 20)
0.50V
0.50V
0.50V
0.50V
0.50V
Maximum peak amplitude allowed for undershoot area
(see Figure 21)
0.50V
0.50V
0.50V
0.50V
0.50V
Maximum overshoot area above VDD (see Figure 20)
0.5 Vns
0.66 Vns
0.80 Vns
1.00 Vns
1.33 Vns
Maximum undershoot area below VSS (see Figure 21)
0.5 Vns
0.66 Vns
0.80 Vns
1.00 Vns
1.33 Vns
Table 26: Clock, Data, Strobe, and Mask Balls
Applies to DQ, DQS, DQS#, RDQS, RDQS#, UDQS, UDQS#, LDQS, LDQS#, DM, UDM, and LDM
Specification
Parameter
-187E
-25/-25E
-3/-3E
-37E
-5E
Maximum peak amplitude allowed for overshoot area
(see Figure 20)
0.50V
0.50V
0.50V
0.50V
0.50V
Maximum peak amplitude allowed for undershoot area
(see Figure 21)
0.50V
0.50V
0.50V
0.50V
0.50V
Maximum overshoot area above VDDQ (see Figure 20)
0.19 Vns
0.23 Vns
0.23 Vns
0.28 Vns
0.38 Vns
Maximum undershoot area below VSSQ (see Figure 21)
0.19 Vns
0.23 Vns
0.23 Vns
0.28 Vns
0.38 Vns
Figure 20: Overshoot
Maximum amplitude
Volts (V)
Overshoot area
VDD/VDDQ
VSS/VSSQ
Time (ns)
Figure 21: Undershoot
Volts (V)
VSS/VSSQ
Undershoot area
Maximum amplitude
Time (ns)
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
AC Overshoot/Undershoot Specification
Table 27: AC Input Test Conditions
Parameter
Symbol
Min
Max
Units
Notes
Input setup timing measurement reference level address
balls, bank address balls, CS#, RAS#, CAS#, WE#, ODT,
DM, UDM, LDM, and CKE
VRS
See Note 2
1, 2, 3, 4
Input hold timing measurement reference level address
balls, bank address balls, CS#, RAS#, CAS#, WE#, ODT,
DM, UDM, LDM, and CKE
VRH
See Note 5
1, 3, 4, 5
VREF(DC)
VDDQ × 0.49 VDDQ × 0.51
V
1, 3, 4, 6
VRD
VIX(AC)
V
1, 3, 7, 8, 9
Input timing measurement reference level (single-ended)
DQS for x4, x8; UDQS, LDQS for x16
Input timing measurement reference level (differential)
CK, CK# for x4, x8, x16; DQS, DQS# for x4, x8; RDQS,
RDQS# for x8; UDQS, UDQS#, LDQS, LDQS# for x16
Notes:
PDF: 09005aef844ec98c
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1. All voltages referenced to VSS.
2. Input waveform setup timing (tISb) is referenced from the input signal crossing at the
VIH(AC) level for a rising signal and VIL(AC) for a falling signal applied to the device under
test, as shown in Figure 30 (page 62).
3. See Input Slew Rate Derating (page 51).
4. The slew rate for single-ended inputs is measured from DC level to AC level, VIL(DC) to
VIH(AC) on the rising edge and VIL(AC) to VIH(DC) on the falling edge. For signals referenced
to VREF, the valid intersection is where the “tangent” line intersects VREF, as shown in
Figure 23 (page 54), Figure 25 (page 55), Figure 27 (page 60), and Figure 29
(page 61).
5. Input waveform hold (tIHb) timing is referenced from the input signal crossing at the
VIL(DC) level for a rising signal and VIH(DC) for a falling signal applied to the device under
test, as shown in Figure 30 (page 62).
6. Input waveform setup timing (tDS) and hold timing (tDH) for single-ended data strobe is
referenced from the crossing of DQS, UDQS, or LDQS through the Vref level applied to
the device under test, as shown in Figure 32 (page 63).
7. Input waveform setup timing (tDS) and hold timing (tDH) when differential data strobe
is enabled is referenced from the cross-point of DQS/DQS#, UDQS/UDQS#, or LDQS/
LDQS#, as shown in Figure 31 (page 62).
8. Input waveform timing is referenced to the crossing point level (VIX) of two input signals
(VTR and VCP) applied to the device under test, where VTR is the true input signal and VCP
is the complementary input signal, as shown in Figure 33 (page 63).
9. The slew rate for differentially ended inputs is measured from twice the DC level to
twice the AC level: 2 × VIL(DC) to 2 × VIH(AC) on the rising edge and 2 × VIL(AC) to 2 ×
VIH(DC) on the falling edge. For example, the CK/CK# would be –250mV to +500mV for
CK rising edge and would be +250mV to –500mV for CK falling edge.
50
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Input Slew Rate Derating
Input Slew Rate Derating
For all input signals, the total tIS (setup time) and tIH (hold time) required is calculated
by adding the data sheet tIS (base) and tIH (base) value to the ΔtIS and ΔtIH derating
value, respectively. Example: tIS (total setup time) = tIS (base) + ΔtIS.
tIS,
the nominal 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. Setup nominal slew rate (tIS) 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 nominal slew rate line between shaded
“VREF(DC) to AC region,” use the nominal slew rate for the derating value (Figure 22
(page 54)).
If the actual signal is later than the nominal 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 DC level is used for the derating value (see Figure 23 (page 54)).
tIH,
the nominal 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). tIH, nominal 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 nominal slew rate line between shaded “DC
to VREF(DC) region,” use the nominal slew rate for the derating value (Figure 24
(page 55)).
If the actual signal is earlier than the nominal slew rate line anywhere between 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 (Figure 25 (page 55)).
Although the total setup time might be negative for slow slew rates (a valid input signal
will not have reached VIH[AC]/VIL[AC] at the time of the rising clock transition), a valid
input signal is still required to complete the transition and reach VIH(AC)/VIL(AC).
For slew rates in between the values listed in Table 28 (page 52) and Table 29
(page 53), the derating values may obtained by linear interpolation.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Input Slew Rate Derating
Table 28: DDR2-400/533 Setup and Hold Time Derating Values (tIS and tIH)
CK, CK# Differential Slew Rate
2.0 V/ns
1.5 V/ns
1.0 V/ns
Command/Address Slew Rate (V/ns)
ΔtIS
ΔtIH
ΔtIS
ΔtIH
ΔtIS
ΔtIH
Units
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
4.0
+187
+94
+217
+124
+247
+154
ps
3.5
+179
+89
+209
+119
+239
+149
ps
3.0
+167
+83
+197
+113
+227
+143
ps
2.5
+150
+75
+180
+105
+210
+135
ps
2.0
+125
+45
+155
+75
+185
+105
ps
1.5
+83
+21
+113
+51
+143
+81
ps
1.0
0
0
+30
+30
+60
+60
ps
0.9
–11
–14
+19
+16
+49
+46
ps
0.8
–25
–31
+5
–1
+35
+29
ps
0.7
–43
–54
–13
–24
+17
+6
ps
0.6
–67
–83
–37
–53
–7
–23
ps
0.5
–110
–125
–80
–95
–50
–65
ps
0.4
–175
–188
–145
–158
–115
–128
ps
0.3
–285
–292
–255
–262
–225
–232
ps
0.25
–350
–375
–320
–345
–290
–315
ps
0.2
–525
–500
–495
–470
–465
–440
ps
0.15
–800
–708
–770
–678
–740
–648
ps
0.1
–1,450
–1,125
–1,420
–1,095
–1,390
–1,065
ps
52
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Input Slew Rate Derating
Table 29: DDR2-667/800/1066 Setup and Hold Time Derating Values (tIS and tIH)
Command/
Address Slew
Rate (V/ns)
CK, CK# Differential Slew Rate
2.0 V/ns
1.5 V/ns
1.0 V/ns
ΔtIS
ΔtIH
ΔtIS
ΔtIH
ΔtIS
ΔtIH
Units
4.0
+150
+94
+180
+124
+210
+154
ps
3.5
+143
+89
+173
+119
+203
+149
ps
3.0
+133
+83
+163
+113
+193
+143
ps
2.5
+120
+75
+150
+105
+180
+135
ps
2.0
+100
+45
+160
+75
+160
+105
ps
1.5
+67
+21
+97
+51
+127
+81
ps
1.0
0
0
+30
+30
+60
+60
ps
0.9
–5
–14
+25
+16
+55
+46
ps
0.8
–13
–31
+17
–1
+47
+29
ps
0.7
–22
–54
+8
–24
+38
+6
ps
0.6
–34
–83
–4
–53
+36
–23
ps
0.5
–60
–125
–30
–95
0
–65
ps
0.4
–100
–188
–70
–158
–40
–128
ps
0.3
–168
–292
–138
–262
–108
–232
ps
0.25
–200
–375
–170
–345
–140
–315
ps
0.2
–325
–500
–295
–470
–265
–440
ps
0.15
–517
–708
–487
–678
–457
–648
ps
0.1
–1,000
–1,125
–970
–1,095
–940
–1,065
ps
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Input Slew Rate Derating
Figure 22: Nominal Slew Rate for tIS
CK
CK#
tIH
tIS
VDDQ
tIS
tIH
VIH(AC)min
VREF to AC
region
VIH(DC)min
Nominal
slew rate
VREF(DC)
Nominal
slew rate
VIL(DC)max
VREF to AC
region
VIL(AC)max
VSS
ΔTF
ΔTR
VREF(DC) - VIL(AC)max
Setup slew rate
=
falling signal
ΔTF
VIH(AC)min - VREF(DC)
Setup slew rate
=
rising signal
ΔTR
Figure 23: Tangent Line for tIS
CK
CK#
VIH(AC)min
tIH
tIS
VDDQ
VREF to AC
region
tIS
tIH
Nominal
line
VIH(DC)min
Tangent
line
VREF(DC)
Tangent
line
VIL(DC)max
Nominal
line
VREF to AC
region
VIL(AC)max
ΔTF
ΔTR
VSS
Tangent line (VIH[AC]min - VREF[DC])
Setup slew rate
=
rising signal
ΔTR
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Input Slew Rate Derating
Figure 24: Nominal Slew Rate for tIH
CK
CK#
tIS
VDDQ
tIS
tIH
tIH
VIH(AC)min
VIH(DC)min
DC to VREF
region
Nominal
slew rate
VREF(DC)
Nominal
slew rate
DC to VREF
region
VIL(DC)max
VIL(AC)max
VSS
ΔTF
ΔTR
Figure 25: Tangent Line for tIH
CK
CK#
tIS
VDDQ
tIS
tIH
tIH
VIH(AC)min
Nominal
line
VIH(DC)min
DC to VREF
region
Tangent
line
VREF(DC)
Tangent
line
Nominal
line
VIL(DC)max
DC to VREF
region
VIL(AC)max
VSS
ΔTR
Tangent line (VREF[DC] - VIL[DC]max)
Hold slew rate
=
rising signal
ΔTR
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55
ΔTF
Hold slew rate Tangent line (VIH[DC]min - VREF[DC])
=
falling signal
ΔTF
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Input Slew Rate Derating
Table 30: DDR2-400/533 tDS, tDH Derating Values with Differential Strobe
All units are shown in picoseconds
DQS, DQS# Differential Slew Rate
DQ
Slew
Rate
(V/ns)
tDS
tDH
tDS
tDH
tDS
tDH
2.0
125
45
125
45
125
45
1.5
83
21
83
21
83
21
1.0
0
0
0
0
0
0
0.9
–
–
–11
–14
–11
0.8
–
–
–
–
0.7
–
–
–
0.6
–
–
–
0.5
–
–
0.4
–
–
4.0 V/ns
Δ
Δ
3.0 V/ns
Δ
Δ
Δ
Δ
1.8 V/ns
Δ
tDS
Δ
1.6 V/ns
Δ
Δ
1.4 V/ns
Δ
Δ
1.2 V/ns
Δ
Δ
1.0 V/ns
Δ
Δ
0.8 V/ns
Δ
Δ
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
–
–
–
–
–
–
–
–
–
–
–
–
95
33
–
–
–
–
–
–
–
–
–
–
12
12
24
24
–
–
–
–
–
–
–
–
–14
1
–2
13
10
25
22
–
–
–
–
–
–
–25
–31
–13
–19
–1
–7
11
5
23
17
–
–
–
–
–
–
–
–31
–42
–19
–30
–7
–18
5
–6
17
6
–
–
–
–
–
–
–
–43
–59
–31
–47
–19
–35
–7
–23
5
–11
–
–
–
–
–
–
–
–
–74
–89
–62
–77
–50
–65
–38
–53
–
–
–
–
–
–
–
–
–
–
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
2.0 V/ns
–127 –140 –115 –128 –103 –116
1. For all input signals, the total tDS and tDH required is calculated by adding the data
sheet value to the derating value listed in Table 30.
2. tDS nominal 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. tDS nominal 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 nominal slew rate line
between the shaded “VREF(DC) to AC region,” use the nominal slew rate for the derating
value (see Figure 26 (page 60)). If the actual signal is later than the nominal 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 DC level is used for the derating value (see
Figure 27 (page 60)).
3. tDH nominal 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). tDH nominal 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 nominal slew rate line
between the shaded “DC level to VREF(DC) region,” use the nominal slew rate for the derating value (see Figure 28 (page 61)). If the actual signal is earlier than the nominal
slew rate line anywhere between 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 (see Figure 29 (page 61)).
4. Although the total setup time might be negative for slow slew rates (a valid input signal
will not have reached VIH[AC]/VIL[AC] at the time of the rising clock transition), a valid input signal is still required to complete the transition and reach VIH(AC)/VIL(AC).
5. For slew rates between the values listed in this table, the derating values may be obtained by linear interpolation.
6. These values are typically not subject to production test. They are verified by design and
characterization.
7. Single-ended DQS requires special derating. The values in Table 32 (page 58) are the
DQS single-ended slew rate derating with DQS referenced at VREF and DQ referenced at
the logic levels tDSb and tDHb. Converting the derated base values from DQ referenced
to the AC/DC trip points to DQ referenced to VREF is listed in Table 34 (page 59) and
Table 35 (page 59). Table 34 provides the VREF-based fully derated values for the DQ
(tDSa and tDHa) for DDR2-533. Table 35 provides the VREF-based fully derated values for
the DQ (tDSa and tDHa) for DDR2-400.
56
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Input Slew Rate Derating
Table 31: DDR2-667/800/1066 tDS, tDH Derating Values with Differential Strobe
All units are shown in picoseconds
DQS, DQS# Differential Slew Rate
DQ
Slew
Rate
(V/ns)
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
2.0
100
63
100
63
100
63
112
75
124
87
136
99
148
111
160
123
172
135
1.5
67
42
67
42
67
42
79
54
91
66
103
78
115
90
127
102
139
114
2.8 V/ns
Δ
Δ
2.4 V/ns
Δ
Δ
2.0 V/ns
Δ
Δ
1.8 V/ns
Δ
Δ
1.6 V/ns
Δ
1.4 V/ns
Δ
Δ
Δ
1.2 V/ns
Δ
Δ
1.0 V/ns
Δ
Δ
0.8 V/ns
Δ
Δ
1.0
0
0
0
0
0
0
12
12
24
24
36
36
48
48
60
60
72
72
0.9
–5
–14
–5
–14
–5
–14
7
–2
19
10
31
22
43
34
55
46
67
58
0.8
–13
–31
–13
–31
–13
–31
–1
–19
11
–7
23
5
35
17
47
29
59
41
0.7
–22
–54
–22
–54
–22
–54
–10
–42
2
–30
14
–18
26
–6
38
6
50
18
0.6
–34
–83
–34
–83
–34
–83
–22
–71
–10
–59
2
–47
14
–35
26
–23
38
–11
0.5
–60
–125
–60
–125
–60
–125
–48
–113
–36
–101
–24
–89
–12
–77
0
–65
12
–53
0.4
–100 –188 –100 –188 –100 –188
–88
–176
–76
–164
–64
–152
–52
–140
–40
–128
–28
–116
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
1. For all input signals the total tDS and tDH required is calculated by adding the data
sheet value to the derating value listed in Table 31.
2. tDS nominal 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. tDS nominal 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 nominal slew rate line
between the shaded “VREF(DC) to AC region,” use the nominal slew rate for the derating
value (see Figure 26 (page 60)). If the actual signal is later than the nominal slew rate
line anywhere between shaded “VREF(DC) to AC region,” the slew rate of a tangent line
to the actual signal from the AC level to DC level is used for the derating value (see Figure 27 (page 60)).
3. tDH nominal 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). tDH nominal 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 nominal slew rate line
between the shaded “DC level to VREF(DC) region,” use the nominal slew rate for the derating value (see Figure 28 (page 61)). If the actual signal is earlier than the nominal
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 (see Figure 29 (page 61)).
4. Although the total setup time might be negative for slow slew rates (a valid input signal
will not have reached VIH[AC]/VIL[AC] at the time of the rising clock transition), a valid input signal is still required to complete the transition and reach VIH(AC)/VIL(AC).
5. For slew rates between the values listed in this table, the derating values may be obtained by linear interpolation.
6. These values are typically not subject to production test. They are verified by design and
characterization.
7. Single-ended DQS requires special derating. The values in Table 32 (page 58) are the
DQS single-ended slew rate derating with DQS referenced at VREF and DQ referenced at
the logic levels tDSb and tDHb. Converting the derated base values from DQ referenced
to the AC/DC trip points to DQ referenced to VREF is listed in Table 33 (page 58). Table 33 provides the VREF-based fully derated values for the DQ (tDSa and tDHa) for
57
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© 2011 Micron Technology, Inc. All rights reserved.
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Input Slew Rate Derating
DDR2-667. It is not advised to operate DDR2-800 and DDR2-1066 devices with singleended DQS; however, Table 32 would be used with the base values.
Table 32: Single-Ended DQS Slew Rate Derating Values Using tDSb and tDHb
Reference points indicated in bold; Derating values are to be used with base tDSb- and tDHb--specified values
DQS Single-Ended Slew Rate Derated (at VREF)
2.0 V/ns
1.8 V/ns
1.6 V/ns
1.4 V/ns
1.2 V/ns
1.0 V/ns
0.8 V/ns
0.6 V/ns
0.4 V/ns
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
2.0
130
53
130
53
130
53
130
53
130
53
145
48
155
45
165
41
175
38
1.5
97
32
97
32
97
32
97
32
97
32
112
27
122
24
132
20
142
17
1.0
30
–10
30
–10
30
–10
30
–10
30
–10
45
–15
55
–18
65
–22
75
–25
0.9
25
–24
25
–24
25
–24
25
–24
25
–24
40
–29
50
–32
60
–36
70
–39
0.8
17
–41
17
–41
17
–41
17
–41
17
–41
32
–46
42
–49
52
–53
61
–56
0.7
5
–64
5
–64
5
–64
5
–64
5
–64
20
–69
30
–72
40
–75
50
–79
0.6
–7
–93
–7
–93
–7
–93
–7
–93
–7
–93
8
–98
18
–102
28
–105
38
–108
0.5
–28 –135 –28 –135 –28 –135 –28 –135 –28 –135 –13 –140
–3
–143
7
–147
17
–150
0.4
–78 –198 –78 –198 –78 –198 –78 –198 –78 –198 –63 –203 –53 –206 –43 –210 –33 –213
DQ (V/ns)
Table 33: Single-Ended DQS Slew Rate Fully Derated (DQS, DQ at VREF) at DDR2-667
Reference points indicated in bold
DQS Single-Ended Slew Rate Derated (at VREF)
2.0 V/ns
1.8 V/ns
1.6 V/ns
1.4 V/ns
1.2 V/ns
1.0 V/ns
0.8 V/ns
0.6 V/ns
DQ (V/ns)
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
2.0
330
291
330
291
330
291
330
291
330
291
345
286
355
282
1.5
330
290
330
290
330
290
330
290
330
290
345
285
355
282
1.0
330
290
330
290
330
290
330
290
330
290
345
285
355
0.9
347
290
347
290
347
290
347
290
347
290
362
285
0.8
367
290
367
290
367
290
367
290
367
290
382
285
0.7
391
290
391
290
391
290
391
290
391
290
406
0.6
426
290
426
290
426
290
426
290
426
290
0.5
472
290
472
290
472
290
472
290
472
0.4
522
289
522
289
522
289
522
289
522
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58
0.4 V/ns
tDH
tDS
tDH
365
29
375
276
365
279
375
275
282
365
278
375
275
372
282
382
278
392
275
392
282
402
278
412
275
285
416
281
426
278
436
275
441
285
451
282
461
278
471
275
290
487
285
497
282
507
278
517
275
289
537
284
547
281
557
278
567
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Input Slew Rate Derating
Table 34: Single-Ended DQS Slew Rate Fully Derated (DQS, DQ at VREF) at DDR2-533
Reference points indicated in bold
DQS Single-Ended Slew Rate Derated (at VREF)
2.0 V/ns
1.8 V/ns
1.6 V/ns
1.4 V/ns
1.2 V/ns
1.0 V/ns
0.8 V/ns
0.6 V/ns
0.4 V/ns
DQ (V/ns)
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
2.0
355
341
355
341
355
341
355
341
355
341
370
336
380
332
390
329
400
326
1.5
364
340
364
340
364
340
364
340
364
340
379
335
389
332
399
329
409
325
1.0
380
340
380
340
380
340
380
340
380
340
395
335
405
332
415
328
425
325
0.9
402
340
402
340
402
340
402
340
402
340
417
335
427
332
437
328
447
325
0.8
429
340
429
340
429
340
429
340
429
340
444
335
454
332
464
328
474
325
0.7
463
340
463
340
463
340
463
340
463
340
478
335
488
331
498
328
508
325
0.6
510
340
510
340
510
340
510
340
510
340
525
335
535
332
545
328
555
325
0.5
572
340
572
340
572
340
572
340
572
340
587
335
597
332
607
328
617
325
0.4
647
339
647
339
647
339
647
339
647
339
662
334
672
331
682
328
692
324
Table 35: Single-Ended DQS Slew Rate Fully Derated (DQS, DQ at VREF) at DDR2-400
Reference points indicated in bold
DQS Single-Ended Slew Rate Derated (at VREF)
2.0 V/ns
1.8 V/ns
1.6 V/ns
1.4 V/ns
1.2 V/ns
1.0 V/ns
0.8 V/ns
0.6 V/ns
0.4 V/ns
DQ (V/ns)
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
2.0
405
391
405
391
405
391
405
391
405
391
420
386
430
382
440
379
450
376
1.5
414
390
414
390
414
390
414
390
414
390
429
385
439
382
449
379
459
375
1.0
430
390
430
390
430
390
430
390
430
390
445
385
455
382
465
378
475
375
0.9
452
390
452
390
452
390
452
390
452
390
467
385
477
382
487
378
497
375
0.8
479
390
479
390
479
390
479
390
479
390
494
385
504
382
514
378
524
375
0.7
513
390
513
390
513
390
513
390
513
390
528
385
538
381
548
378
558
375
0.6
560
390
560
390
560
390
560
390
560
390
575
385
585
382
595
378
605
375
0.5
622
390
622
390
622
390
622
390
622
390
637
385
647
382
657
378
667
375
0.4
697
389
697
389
697
389
697
389
697
389
712
384
722
381
732
378
742
374
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Input Slew Rate Derating
Figure 26: Nominal Slew Rate for tDS
DQS1
DQS#1
tDS
tDH
tDS
VDDQ
VIH(AC)min
tDH
VREF to AC
region
VIH(DC)min
Nominal
slew rate
VREF(DC)
Nominal
slew rate
VIL(DC)max
VREF to AC
region
VIL(AC)max
VSS
ΔTF
ΔTR
Setup slew rate
=
falling signal
Note:
VREF(DC) - VIL(AC)max
VIH(AC)min - VREF(DC)
Setup slew rate
=
rising signal
ΔTR
ΔTF
1. DQS, DQS# signals must be monotonic between VIL(DC)max and VIH(DC)min.
Figure 27: Tangent Line for tDS
DQS1
DQS#1
t
DS
VDDQ
t
t
DH
VIH(AC)min
DS
t
DH
Nominal
line
VREF to AC
region
VIH(DC)min
Tangent line
VREF(DC)
Tangent line
VIL(DC)max
Nominal line
VREF to AC
region
VIL(AC)max
ΔTR
ΔTF
VSS
Setup slew rate
=
falling signal
Note:
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Tangent line (VREF[DC] - VIL[AC]max)
ΔTF
Tangent line (VIH[AC]min - VREF[DC])
Setup slew rate
=
rising signal
ΔTR
1. DQS, DQS# signals must be monotonic between VIL(DC)max and VIH(DC)min.
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Input Slew Rate Derating
Figure 28: Nominal Slew Rate for tDH
DQS1
DQS#1
tIS
VDDQ
tIS
tIH
tIH
VIH(AC)min
VIH(DC)min
DC to VREF
region
Nominal
slew rate
VREF(DC)
Nominal
slew rate
DC to VREF
region
VIL(DC)max
VIL(AC)max
VSS
ΔTF
ΔTR
Hold slew rate VIH(DC)min - VREF(DC)
=
falling signal
ΔTF
Hold slew rate VREF(DC) - VIL(DC)max
=
rising signal
ΔTR
Note:
1. DQS, DQS# signals must be monotonic between VIL(DC)max and VIH(DC)min.
Figure 29: Tangent Line for tDH
DQS1
DQS#1
tIS
VDDQ
tIS
tIH
tIH
VIH(AC)min
Nominal
line
VIH(DC)min
DC to VREF
region
Tangent
line
VREF(DC)
Tangent
line
Nominal
line
VIL(DC)max
DC to VREF
region
VIL(AC)max
VSS
Hold slew rate
=
rising signal
Note:
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Tangent line (VREF[DC] - VIL[DC]max)
ΔTR
ΔTF
ΔTR
Hold slew rate Tangent line (VIH[DC]min - VREF[DC])
=
falling signal
ΔTF
1. DQS, DQS# signals must be monotonic between VIL(DC)max and VIH(DC)min.
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Input Slew Rate Derating
Figure 30: AC Input Test Signal Waveform Command/Address Balls
CK#
CK
tIS
b
Logic levels
tIS
b
tIH
b
tIH
b
VDDQ
Vswing (MAX)
VIH(AC)min
VIH(DC)min
VREF(DC)
VIL(DC)min
VIL(AC)min
VSSQ
VREF levels
tIS
a
tIS
a
tIH
a
tIH
a
Figure 31: AC Input Test Signal Waveform for Data with DQS, DQS# (Differential)
DQS#
DQS
tDS
b
tDH
b
tDS
b
tDH
b
Logic levels
VDDQ
Vswing (MAX)
VIH(AC)min
VIH(DC)min
VREF(DC)
VIL(DC)max
VIL(AC)max
VSSQ
VREF levels
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tDS
a
tDH
a
62
tDS
a
tDH
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Input Slew Rate Derating
Figure 32: AC Input Test Signal Waveform for Data with DQS (Single-Ended)
VREF
DQS
tDS
b
Logic levels
tDH
b
tDS
b
tDH
b
VDDQ
VIH(AC)min
Vswing (MAX)
VIH(DC)min
VREF(DC)
VIL(DC)max
VIL(AC)max
VSSQ
VREF levels
tDS
a
tDH
a
tDS
a
tDH
a
Figure 33: AC Input Test Signal Waveform (Differential)
VDDQ
VTR
Crossing point
Vswing
VIX
VCP
VSSQ
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Commands
Commands
Truth Tables
The following tables provide a quick reference of available DDR2 SDRAM commands,
including CKE power-down modes and bank-to-bank commands.
Table 36: Truth Table – DDR2 Commands
Notes: 1–3 apply to the entire table
CKE
Previous
Cycle
Current
Cycle
CS#
RAS#
CAS#
WE#
LOAD MODE
H
H
L
L
L
L
BA
REFRESH
H
H
L
L
L
H
X
X
X
X
SELF REFRESH entry
H
L
L
L
L
H
X
X
X
X
SELF REFRESH exit
L
H
H
X
X
X
X
X
X
X
4, 7
L
H
H
H
6
Function
BA2–
BA0 An–A11
A10
A9–A0 Notes
OP code
4, 6
Single bank
PRECHARGE
H
H
L
L
H
L
BA
X
L
X
All banks PRECHARGE
H
H
L
L
H
L
X
X
H
X
Bank ACTIVATE
H
H
L
L
H
H
BA
WRITE
H
H
L
H
L
L
BA
Column
address
L
Column 4, 5, 6,
address
8
WRITE with auto
precharge
H
H
L
H
L
L
BA
Column
address
H
Column 4, 5, 6,
address
8
READ
H
H
L
H
L
H
BA
Column
address
L
Column 4, 5, 6,
address
8
READ with auto
precharge
H
H
L
H
L
H
BA
Column
address
H
Column 4, 5, 6,
address
8
NO OPERATION
H
X
L
H
H
H
X
X
X
X
Device DESELECT
H
X
H
X
X
X
X
X
X
X
Power-down entry
H
L
H
X
X
X
X
X
X
X
9
L
H
H
H
Power-down exit
L
H
H
X
X
X
X
X
X
X
9
L
H
H
H
Notes:
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Row address
4
1. All DDR2 SDRAM commands are defined by states of CS#, RAS#, CAS#, WE#, and CKE at
the rising edge of the clock.
2. The state of ODT does not affect the states described in this table. The ODT function is
not available during self refresh. See ODT Timing (page 121) for details.
3. “X” means “H or L” (but a defined logic level) for valid IDD measurements.
4. BA2 is only applicable for densities ≥1Gb.
5. An n is the most significant address bit for a given density and configuration. Some larger address bits may be “Don’t Care” during column addressing, depending on density
and configuration.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Commands
6. Bank addresses (BA) determine which bank is to be operated upon. BA during a LOAD
MODE command selects which mode register is programmed.
7. SELF REFRESH exit is asynchronous.
8. Burst reads or writes at BL = 4 cannot be terminated or interrupted. See Figure 47
(page 90) and Figure 59 (page 101) for other restrictions and details.
9. The power-down mode does not perform any REFRESH operations. The duration of powerdown is limited by the refresh requirements outlined in the AC parametric section.
Table 37: Truth Table – Current State Bank n – Command to Bank n
Notes: 1–6 apply to the entire table
Current
State
CS#
RAS#
CAS#
Any
WE#
Command/Action
Notes
H
X
X
X
DESELECT (NOP/continue previous operation)
L
H
H
H
NO OPERATION (NOP/continue previous operation)
L
L
H
H
ACTIVATE (select and activate row)
L
L
L
H
REFRESH
7
L
L
L
L
LOAD MODE
7
L
H
L
H
READ (select column and start READ burst)
8
L
H
L
L
WRITE (select column and start WRITE burst)
8
L
L
H
L
PRECHARGE (deactivate row in bank or banks)
9
Read (auto
precharge
disabled)
L
H
L
H
READ (select column and start new READ burst)
8
L
H
L
L
WRITE (select column and start WRITE burst)
L
L
H
L
PRECHARGE (start PRECHARGE)
9
Write
(auto precharge disabled)
L
H
L
H
READ (select column and start READ burst)
8
L
H
L
L
WRITE (select column and start new WRITE burst)
8
L
L
H
L
PRECHARGE (start PRECHARGE)
9
Idle
Row active
Notes:
8, 10
1. This table applies when CKEn - 1 was HIGH and CKEn is HIGH and after tXSNR has been
met (if the previous state was self refresh).
2. This table is bank-specific, except where noted (the current state is for a specific bank
and the commands shown are those allowed to be issued to that bank when in that
state). Exceptions are covered in the notes below.
3. Current state definitions:
The bank has been precharged, tRP has been met, and any READ burst is complete.
A row in the bank has been activated, and tRCD has been met. No data bursts/
Row
active: accesses and no register accesses are in progress.
Read: A READ burst has been initiated, with auto precharge disabled and has not yet
terminated.
Write: A WRITE burst has been initiated with auto precharge disabled and has not yet
terminated.
Idle:
4. The following states must not be interrupted by a command issued to the same bank.
Issue DESELECT or NOP commands, or allowable commands to the other bank, on any
clock edge occurring during these states. Allowable commands to the other bank are
determined by its current state and this table, and according to Table 38 (page 67).
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Commands
Starts with registration of a PRECHARGE command and ends when tRP
is met. After tRP is met, the bank will be in the idle state.
Read with au- Starts with registration of a READ command with auto precharge enato precharge bled and ends when tRP has been met. After tRP is met, the bank will
be in the idle state.
enabled:
Row activate: Starts with registration of an ACTIVATE command and ends when
tRCD is met. After tRCD is met, the bank will be in the row active state.
Write with au- Starts with registration of a WRITE command with auto precharge enato precharge bled and ends when tRP has been met. After tRP is met, the bank will
be in the idle state.
enabled:
5. The following states must not be interrupted by any executable command (DESELECT or
NOP commands must be applied on each positive clock edge during these states):
Precharge:
Starts with registration of a REFRESH command and ends when tRFC is
met. After tRFC is met, the DDR2 SDRAM will be in the all banks idle state.
Starts with registration of the LOAD MODE command and ends when
Accessing
tMRD has been met. After tMRD is met, the DDR2 SDRAM will be in the
mode
all banks idle state.
register:
Precharge Starts with registration of a PRECHARGE ALL command and ends when
tRP is met. After tRP is met, all banks will be in the idle state.
all:
All states and sequences not shown are illegal or reserved.
Not bank-specific; requires that all banks are idle and bursts are not in progress.
READs or WRITEs listed in the Command/Action column include READs or WRITEs with
auto precharge enabled and READs or WRITEs with auto precharge disabled.
May or may not be bank-specific; if multiple banks are to be precharged, each must be
in a valid state for precharging.
A WRITE command may be applied after the completion of the READ burst.
Refresh:
6.
7.
8.
9.
10.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Commands
Table 38: Truth Table – Current State Bank n – Command to Bank m
Notes: 1–6 apply to the entire table
Current State
CS#
RAS# CAS#
Any
WE#
Command/Action
Notes
H
X
X
X
DESELECT (NOP/continue previous operation)
L
H
H
H
NO OPERATION (NOP/continue previous operation)
Idle
X
X
X
X
Any command otherwise allowed to bank m
Row
active, active,
or precharge
L
L
H
H
ACTIVATE (select and activate row)
L
H
L
H
READ (select column and start READ burst)
7
L
H
L
L
WRITE (select column and start WRITE burst)
7
L
L
H
L
PRECHARGE
L
L
H
H
ACTIVATE (select and activate row)
L
H
L
H
READ (select column and start new READ burst)
L
H
L
L
WRITE (select column and start WRITE burst)
L
L
H
L
PRECHARGE
L
L
H
H
ACTIVATE (select and activate row)
L
H
L
H
READ (select column and start READ burst)
L
H
L
L
WRITE (select column and start new WRITE burst)
L
L
H
L
PRECHARGE
L
L
H
H
ACTIVATE (select and activate row)
L
H
L
H
READ (select column and start new READ burst)
L
H
L
L
WRITE (select column and start WRITE burst)
L
L
H
L
PRECHARGE
L
L
H
H
ACTIVATE (select and activate row)
L
H
L
H
READ (select column and start READ burst)
L
H
L
L
WRITE (select column and start new WRITE burst)
L
L
H
L
PRECHARGE
Read (auto
precharge
disabled)
Write (auto precharge
disabled)
Read (with
auto
precharge)
Write (with
auto
precharge)
Notes:
7, 9, 10
7
7
7, 8
7, 10
7
1. This table applies when CKEn - 1 was HIGH and CKEn is HIGH and after tXSNR has been
met (if the previous state was self refresh).
2. This table describes an alternate bank operation, except where noted (the current state
is for bank n and the commands shown are those allowed to be issued to bank m, assuming that bank m is in such a state that the given command is allowable). Exceptions are
covered in the notes below.
3. Current state definitions:
Idle:
Row active:
Read:
Write:
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7, 8
The bank has been precharged, tRP has been met, and any READ
burst is complete.
A row in the bank has been activated and tRCD has been met.
No data bursts/accesses and no register accesses are in progress.
A READ burst has been initiated with auto precharge disabled
and has not yet terminated.
A WRITE burst has been initiated with auto precharge disabled
and has not yet terminated.
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Commands
READ with auto
precharge enabled/
WRITE with auto
precharge enabled:
4.
5.
6.
7.
8.
9.
10.
The READ with auto precharge enabled or WRITE with auto precharge enabled states can each be broken into two parts: the
access period and the precharge period. For READ with auto precharge, the precharge period is defined as if the same burst was
executed with auto precharge disabled and then followed with
the earliest possible PRECHARGE command that still accesses all
of the data in the burst. For WRITE with auto precharge, the precharge period begins when tWR ends, with tWR measured as if
auto precharge was disabled. The access period starts with registration of the command and ends where the precharge period
(or tRP) begins. This device supports concurrent auto precharge
such that when a READ with auto precharge is enabled or a
WRITE with auto precharge is enabled, any command to other
banks is allowed, as long as that command does not interrupt
the read or write data transfer already in process. In either case,
all other related limitations apply (contention between read data and write data must be avoided).
The minimum delay from a READ or WRITE command with auto precharge enabled to
a command to a different bank is summarized in Table 39 (page 68).
REFRESH and LOAD MODE commands may only be issued when all banks are idle.
Not used.
All states and sequences not shown are illegal or reserved.
READs or WRITEs listed in the Command/Action column include READs or WRITEs with
auto precharge enabled and READs or WRITEs with auto precharge disabled.
A WRITE command may be applied after the completion of the READ burst.
Requires appropriate DM.
The number of clock cycles required to meet tWTR is either two or tWTR/tCK, whichever
is greater.
Table 39: Minimum Delay with Auto Precharge Enabled
From Command (Bank n)
WRITE with auto precharge
READ with auto precharge
Minimum Delay
(with Concurrent Auto Precharge)
To Command (Bank m)
READ or READ with auto precharge
(CL - 1) + (BL/2) +
tWTR
Units
tCK
WRITE or WRITE with auto precharge
(BL/2)
tCK
PRECHARGE or ACTIVATE
1
tCK
READ or READ with auto precharge
(BL/2)
tCK
WRITE or WRITE with auto precharge
(BL/2) + 2
tCK
PRECHARGE or ACTIVATE
1
tCK
DESELECT
The DESELECT function (CS# HIGH) prevents new commands from being executed by
the DDR2 SDRAM. The DDR2 SDRAM is effectively deselected. Operations already in
progress are not affected. DESELECT is also referred to as COMMAND INHIBIT.
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Commands
NO OPERATION (NOP)
The NO OPERATION (NOP) command is used to instruct the selected DDR2 SDRAM to
perform a NOP (CS# is LOW; RAS#, CAS#, and WE are HIGH). This prevents unwanted
commands from being registered during idle or wait states. Operations already in progress are not affected.
LOAD MODE (LM)
The mode registers are loaded via bank address and address inputs. The bank address
balls determine which mode register will be programmed. See Mode Register (MR)
(page 70). The LM command can only be issued when all banks are idle, and a subsequent executable command cannot be issued until tMRD is met.
ACTIVATE
The ACTIVATE command is used to open (or activate) a row in a particular bank for a
subsequent access. The value on the bank address inputs determines the bank, and the
address inputs select the row. This row remains active (or open) for accesses until a precharge command is issued to that bank. A precharge command must be issued before
opening a different row in the same bank.
READ
The READ command is used to initiate a burst read access to an active row. The value
on the bank address inputs determine the bank, and the address provided on address
inputs A0–Ai (where Ai is the most significant column address bit for a given configuration) selects the starting column location. The value on input A10 determines whether
or not auto precharge is used. If auto precharge is selected, the row being accessed will
be precharged at the end of the read burst; if auto precharge is not selected, the row will
remain open for subsequent accesses.
DDR2 SDRAM also supports the AL feature, which allows a READ or WRITE command
to be issued prior to tRCD (MIN) by delaying the actual registration of the READ/WRITE
command to the internal device by AL clock cycles.
WRITE
The WRITE command is used to initiate a burst write access to an active row. The value
on the bank select inputs selects the bank, and the address provided on inputs A0–Ai
(where Ai is the most significant column address bit for a given configuration) selects
the starting column location. The value on input A10 determines whether or not auto
precharge is used. If auto precharge is selected, the row being accessed will be precharged at the end of the WRITE burst; if auto precharge is not selected, the row will
remain open for subsequent accesses.
DDR2 SDRAM also supports the AL feature, which allows a READ or WRITE command
to be issued prior to tRCD (MIN) by delaying the actual registration of the READ/WRITE
command to the internal device by AL clock cycles.
Input data appearing on the DQ is written to the memory array subject to the DM input
logic level appearing coincident with the data. If a given DM signal is registered LOW,
the corresponding data will be written to memory; if the DM signal is registered HIGH,
the corresponding data inputs will be ignored, and a WRITE will not be executed to that
byte/column location (see Figure 64 (page 106)).
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Mode Register (MR)
PRECHARGE
The PRECHARGE command is used to deactivate the open row in a particular bank or
the open row in all banks. The bank(s) will be available for a subsequent row activation
a specified time (tRP) after the PRECHARGE command is issued, except in the case of
concurrent auto precharge, where a READ or WRITE command to a different bank is
allowed as long as it does not interrupt the data transfer in the current bank and does
not violate any other timing parameters. After a bank has been precharged, it is in the
idle state and must be activated prior to any READ or WRITE commands being issued to
that bank. A PRECHARGE command is allowed if there is no open row in that bank (idle
state) or if the previously open row is already in the process of precharging. However,
the precharge period will be determined by the last PRECHARGE command issued to
the bank.
REFRESH
REFRESH is used during normal operation of the DDR2 SDRAM and is analogous to CAS#before-RAS# (CBR) REFRESH. All banks must be in the idle mode prior to issuing a
REFRESH command. This command is nonpersistent, so it must be issued each time a
refresh is required. The addressing is generated by the internal refresh controller. This
makes the address bits a “Don’t Care” during a REFRESH command.
SELF REFRESH
The SELF REFRESH command can be used to retain data in the DDR2 SDRAM, even if
the rest of the system is powered down. When in the self refresh mode, the DDR2
SDRAM retains data without external clocking. All power supply inputs (including Vref)
must be maintained at valid levels upon entry/exit and during SELF REFRESH operation.
The SELF REFRESH command is initiated like a REFRESH command except CKE is
LOW. The DLL is automatically disabled upon entering self refresh and is automatically
enabled upon exiting self refresh.
Mode Register (MR)
The mode register is used to define the specific mode of operation of the DDR2 SDRAM.
This definition includes the selection of a burst length, burst type, CAS latency, operating mode, DLL RESET, write recovery, and power-down mode, as shown in Figure 34
(page 71). Contents of the mode register can be altered by re-executing the LOAD
MODE (LM) command. If the user chooses to modify only a subset of the MR variables,
all variables must be programmed when the command is issued.
The MR is programmed via the LM command and will retain the stored information
until it is programmed again or until the device loses power (except for bit M8, which is
self-clearing). Reprogramming the mode register will not alter the contents of the memory array, provided it is performed correctly.
The LM command can only be issued (or reissued) when all banks are in the precharged
state (idle state) and no bursts are in progress. The controller must wait the specified
time tMRD before initiating any subsequent operations such as an ACTIVATE command. Violating either of these requirements will result in an unspecified operation.
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Mode Register (MR)
Burst Length
Burst length is defined by bits M0–M2, as shown in Figure 34. Read and write accesses
to the DDR2 SDRAM are burst-oriented, with the burst length being programmable to
either four or eight. The burst length determines the maximum number of column locations that can be accessed for a given READ or WRITE command.
When a READ or WRITE command is issued, a block of columns equal to the burst
length is effectively selected. All accesses for that burst take place within this block,
meaning that the burst will wrap within the block if a boundary is reached. The block is
uniquely selected by A2–Ai when BL = 4 and by A3–Ai when BL = 8 (where Ai is the most
significant column address bit for a given configuration). The remaining (least significant) address bit(s) is (are) used to select the starting location within the block. The
programmed burst length applies to both read and write bursts.
Figure 34: MR Definition
1
2
BA2 BA1 BA0 An A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
Address Bus
16 15 14 n 12 11 10
0
MR
WR
0 PD
Mode Register (Mx)
9
8
M12 PD Mode
0
Fast exit
(normal)
1
Slow exit
(low power)
M11 M10 M9
M15 M14
Notes:
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7
6
5
4
3
2
1
0
DLL TM CAS# Latency BT Burst Length
M2 M1 M0 Burst Length
M7 Mode
0 Normal
0
0
0
Reserved
1
0
0
1
Reserved
0
1
0
4
0
1
1
8
Test
M8 DLL Reset
0
No
1
0
0
Reserved
1
Yes
1
0
1
Reserved
1
1
0
Reserved
1
1
1
Reserved
Write Recovery
0
0
0
Reserved
0
0
1
2
M3
0
1
0
3
0
Sequential
0
1
1
4
1
Interleaved
1
0
0
5
1
0
1
6
1
1
0
7
1
1
1
8
Mode Register Definition
0
0
Mode register (MR)
0
1
Extended mode register (EMR)
1
0
Extended mode register (EMR2)
1
1
Extended mode register (EMR3)
M6 M5 M4
Burst Type
CAS Latency (CL)
0
0
0
Reserved
0
0
1
Reserved
0
1
0
Reserved
0
1
1
3
1
0
0
4
1
0
1
5
1
1
0
6
1
1
1
7
1. M16 (BA2) is only applicable for densities ≥1Gb, reserved for future use, and must be
programmed to “0.”
2. Mode bits (Mn) with corresponding address balls (An) greater than M12 (A12) are reserved for future use and must be programmed to “0.”
3. Not all listed WR and CL options are supported in any individual speed grade.
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Mode Register (MR)
Burst Type
Accesses within a given burst may be programmed to be either sequential or interleaved. The burst type is selected via bit M3, as shown in Figure 34. The ordering of
accesses within a burst is determined by the burst length, the burst type, and the starting column address, as shown in Table 40. DDR2 SDRAM supports 4-bit burst mode
and 8-bit burst mode only. For 8-bit burst mode, full interleaved address ordering is
supported; however, sequential address ordering is nibble-based.
Table 40: Burst Definition
Burst Length
Starting Column Address
(A2, A1, A0)
Burst Type = Sequential
Burst Type = Interleaved
00
0, 1, 2, 3
0, 1, 2, 3
01
1, 2, 3, 0
1, 0, 3, 2
10
2, 3, 0, 1
2, 3, 0, 1
11
3, 0, 1, 2
3, 2, 1, 0
000
0, 1, 2, 3, 4, 5, 6, 7
0, 1, 2, 3, 4, 5, 6, 7
001
1, 2, 3, 0, 5, 6, 7, 4
1, 0, 3, 2, 5, 4, 7, 6
010
2, 3, 0, 1, 6, 7, 4, 5
2, 3, 0, 1, 6, 7, 4, 5
011
3, 0, 1, 2, 7, 4, 5, 6
3, 2, 1, 0, 7, 6, 5, 4
100
4, 5, 6, 7, 0, 1, 2, 3
4, 5, 6, 7, 0, 1, 2, 3
101
5, 6, 7, 4, 1, 2, 3, 0
5, 4, 7, 6, 1, 0, 3, 2
110
6, 7, 4, 5, 2, 3, 0, 1
6, 7, 4, 5, 2, 3, 0, 1
111
7, 4, 5, 6, 3, 0, 1, 2
7, 6, 5, 4, 3, 2, 1, 0
4
8
Order of Accesses Within a Burst
Operating Mode
The normal operating mode is selected by issuing a command with bit M7 set to “0,”
and all other bits set to the desired values, as shown in Figure 34 (page 71). When bit M7
is “1,” no other bits of the mode register are programmed. Programming bit M7 to “1”
places the DDR2 SDRAM into a test mode that is only used by the manufacturer and
should not be used. No operation or functionality is guaranteed if M7 bit is “1.”
DLL RESET
DLL RESET is defined by bit M8, as shown in Figure 34. Programming bit M8 to “1” will
activate the DLL RESET function. Bit M8 is self-clearing, meaning it returns back to a
value of “0” after the DLL RESET function has been issued.
Anytime the DLL RESET function is used, 200 clock cycles must occur before a READ
command can be issued to allow time for the internal clock to be synchronized with the
external clock. Failing to wait for synchronization to occur may result in a violation of
the tAC or tDQSCK parameters.
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Mode Register (MR)
Write Recovery
Write recovery (WR) time is defined by bits M9–M11, as shown in Figure 34 (page 71).
The WR register is used by the DDR2 SDRAM during WRITE with auto precharge operation. During WRITE with auto precharge operation, the DDR2 SDRAM delays the internal auto precharge operation by WR clocks (programmed in bits M9–M11) from the last
data burst. An example of WRITE with auto precharge is shown in Figure 63 (page 105).
WR values of 2, 3, 4, 5, 6, 7, or 8 clocks may be used for programming bits M9–M11. The
user is required to program the value of WR, which is calculated by dividing tWR (in
nanoseconds) by tCK (in nanoseconds) and rounding up a noninteger value to the next
integer; WR (cycles) = tWR (ns)/tCK (ns). Reserved states should not be used as an unknown operation or incompatibility with future versions may result.
Power-Down Mode
Active power-down (PD) mode is defined by bit M12, as shown in Figure 34. PD mode
enables the user to determine the active power-down mode, which determines performance versus power savings. PD mode bit M12 does not apply to precharge PD mode.
When bit M12 = 0, standard active PD mode, or “fast-exit” active PD mode, is enabled.
The tXARD parameter is used for fast-exit active PD exit timing. The DLL is expected to
be enabled and running during this mode.
When bit M12 = 1, a lower-power active PD mode, or “slow-exit” active PD mode, is
enabled. The tXARDS parameter is used for slow-exit active PD exit timing. The DLL can
be enabled but “frozen” during active PD mode because the exit-to-READ command
timing is relaxed. The power difference expected between IDD3P normal and IDD3P lowpower mode is defined in the DDR2 IDD Specifications and Conditions table.
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Mode Register (MR)
CAS Latency (CL)
The CAS latency (CL) is defined by bits M4–M6, as shown in Figure 34 (page 71). CL is
the delay, in clock cycles, between the registration of a READ command and the availability of the first bit of output data. The CL can be set to 3, 4, 5, 6, or 7 clocks, depending
on the speed grade option being used.
DDR2 SDRAM does not support any half-clock latencies. Reserved states should not be
used as an unknown operation otherwise incompatibility with future versions may result.
DDR2 SDRAM also supports a feature called posted CAS additive latency (AL). This feature allows the READ command to be issued prior to tRCD (MIN) by delaying the
internal command to the DDR2 SDRAM by AL clocks. The AL feature is described in
further detail in Posted CAS Additive Latency (AL) (page 77).
Examples of CL = 3 and CL = 4 are shown in Figure 35; both assume AL = 0. If a READ
command is registered at clock edge n, and the CL is m clocks, the data will be available
nominally coincident with clock edge n + m (this assumes AL = 0).
Figure 35: CL
CK#
T0
T1
T2
T3
T4
T5
T6
READ
NOP
NOP
NOP
NOP
NOP
NOP
CK
Command
DQS, DQS#
DO
n
DQ
DO
n+1
DO
n+2
DO
n+3
CL = 3 (AL = 0)
CK#
T0
T1
T2
T3
T4
T5
T6
READ
NOP
NOP
NOP
NOP
NOP
NOP
CK
Command
DQS, DQS#
DO
n
DQ
DO
n+1
DO
n+2
DO
n+3
CL = 4 (AL = 0)
Transitioning data
Notes:
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Don’t care
1. BL = 4.
2. Posted CAS# additive latency (AL) = 0.
3. Shown with nominal tAC, tDQSCK, and tDQSQ.
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Extended Mode Register (EMR)
Extended Mode Register (EMR)
The extended mode register controls functions beyond those controlled by the mode
register; these additional functions are DLL enable/disable, output drive strength, ondie termination (ODT), posted AL, off-chip driver impedance calibration (OCD), DQS#
enable/disable, RDQS/RDQS# enable/disable, and output disable/enable. These functions are controlled via the bits shown in Figure 36. The EMR is programmed via the LM
command and will retain the stored information until it is programmed again or the
device loses power. Reprogramming the EMR will not alter the contents of the memory
array, provided it is performed correctly.
The EMR must be loaded when all banks are idle and no bursts are in progress, and the
controller must wait the specified time tMRD before initiating any subsequent operation. Violating either of these requirements could result in an unspecified operation.
Figure 36: EMR Definition
1
2
BA2 BA1 BA0 An A12
16
0
A10 A9 A8 A7 A6 A5 A4 A3 A2
15 14 n 12 11 10 9 8 7 6 5 4 3 2
1 0
MRS 0 Out RDQS DQS# OCD Program RTT Posted CAS# RTT ODS DLL
Extended mode
register (Ex)
Outputs
E0
DLL Enable
0
Enabled
E6 E2 RTT (Nominal)
0
Enable (normal)
1
Disabled
0 0
RTT disabled
1
Disable (test/debug)
0 1
75Ω
1 0
150Ω
E1
1 1
50Ω
0
Full
1
Reduced
0
No
1
Yes
E10 DQS# Enable
E15 E14
Output Drive Strength
3
E5 E4 E3 Posted CAS# Additive Latency (AL)
0
Enable
0
0
0
0
1
Disable
0
0
1
1
0
1
0
2
0
1
1
3
1
0
0
4
1
0
1
5
1
1
0
6
1
1
1
Reserved
4
E9 E8 E7 OCD Operation
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Address bus
E12
E11 RDQS Enable
Notes:
A1 A0
0
0
0
OCD exit
0
0
1
Reserved
0
1
0
Reserved
1
0
0
Reserved
1
1
1
Enable OCD defaults
Mode Register Set
0
0
Mode register (MR)
0
1
Extended mode register (EMR)
1
0
Extended mode register (EMR2)
1
1
Extended mode register (EMR3)
1. E16 (BA2) is only applicable for densities ≥1Gb, reserved for future use, and must be programmed to “0.”
2. Mode bits (En) with corresponding address balls (An) greater than E12 (A12) are reserved for future use and must be programmed to “0.”
3. Not all listed AL options are supported in any individual speed grade.
4. As detailed in the Initialization (page 81) section notes, during initialization of the
OCD operation, all three bits must be set to “1” for the OCD default state, then set to
“0” before initialization is finished.
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Extended Mode Register (EMR)
DLL Enable/Disable
The DLL may be enabled or disabled by programming bit E0 during the LM command,
as shown in Figure 36 (page 75). These specifications are applicable when the DLL is
enabled for normal operation. DLL enable is required during power-up initialization
and upon returning to normal operation after having disabled the DLL for the purpose
of debugging or evaluation. Enabling the DLL should always be followed by resetting
the DLL using the LM command.
The DLL is automatically disabled when entering SELF REFRESH operation and is automatically re-enabled and reset upon exit of SELF REFRESH operation.
Anytime the DLL is enabled (and subsequently reset), 200 clock cycles must occur before a READ command can be issued to allow time for the internal clock to synchronize
with the external clock. Failing to wait for synchronization to occur may result in a violation of the tAC or tDQSCK parameters.
Anytime the DLL is disabled and the device is operated below 25 MHz, any AUTO REFRESH command should be followed by a PRECHARGE ALL command.
Output Drive Strength
The output drive strength is defined by bit E1, as shown in Figure 36. The normal drive
strength for all outputs is specified to be SSTL_18. Programming bit E1 = 0 selects normal (full strength) drive strength for all outputs. Selecting a reduced drive strength
option (E1 = 1) will reduce all outputs to approximately 45 to 60 percent of the SSTL_18
drive strength. This option is intended for the support of lighter load and/or point-topoint environments.
DQS# Enable/Disable
The DQS# ball is enabled by bit E10. When E10 = 0, DQS# is the complement of the
differential data strobe pair DQS/DQS#. When disabled (E10 = 1), DQS is used in a singleended mode and the DQS# ball is disabled. When disabled, DQS# should be left floating; however, it may be tied to ground via a 20Ω to 10kΩ resistor. This function is also
used to enable/disable RDQS#. If RDQS is enabled (E11 = 1) and DQS# is enabled (E10 =
0), then both DQS# and RDQS# will be enabled.
RDQS Enable/Disable
The RDQS ball is enabled by bit E11, as shown in Figure 36. This feature is only applicable to the x8 configuration. When enabled (E11 = 1), RDQS is identical in function and
timing to data strobe DQS during a READ. During a WRITE operation, RDQS is ignored
by the DDR2 SDRAM.
Output Enable/Disable
The OUTPUT ENABLE function is defined by bit E12, as shown in Figure 36. When enabled (E12 = 0), all outputs (DQ, DQS, DQS#, RDQS, RDQS#) function normally. When
disabled (E12 = 1), all outputs (DQ, DQS, DQS#, RDQS, RDQS#) are disabled, thus removing output buffer current. The output disable feature is intended to be used during IDD
characterization of read current.
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Extended Mode Register (EMR)
On-Die Termination (ODT)
ODT effective resistance, RTT(EFF), is defined by bits E2 and E6 of the EMR, as shown in
Figure 36 (page 75). The ODT feature is designed to improve signal integrity of the memory channel by allowing the DDR2 SDRAM controller to independently turn on/off ODT
for any or all devices. RTT effective resistance values of 50Ω, 75Ω, and 150Ω are selectable and apply to each DQ, DQS/DQS#, RDQS/RDQS#, UDQS/UDQS#, LDQS/LDQS#,
DM, and UDM/LDM signals. Bits (E6, E2) determine what ODT resistance is enabled by
turning on/off “sw1,” “sw2,” or “sw3.” The ODT effective resistance value is selected by
enabling switch “sw1,” which enables all R1 values that are 150Ω each, enabling an effective resistance of 75Ω (RTT2 [EFF] = R2/2). Similarly, if “sw2” is enabled, all R2 values
that are 300Ω each, enable an effective ODT resistance of 150Ω (RTT2[EFF] = R2/2).
Switch “sw3” enables R1 values of 100Ω, enabling effective resistance of 50Ω. Reserved
states should not be used, as an unknown operation or incompatibility with future versions may result.
The ODT control ball is used to determine when RTT(EFF) is turned on and off, assuming
ODT has been enabled via bits E2 and E6 of the EMR. The ODT feature and ODT input
ball are only used during active, active power-down (both fast-exit and slow-exit
modes), and precharge power-down modes of operation.
ODT must be turned off prior to entering self refresh mode. During power-up and initialization of the DDR2 SDRAM, ODT should be disabled until the EMR command is
issued. This will enable the ODT feature, at which point the ODT ball will determine the
RTT(EFF) value. Anytime the EMR enables the ODT function, ODT may not be driven
HIGH until eight clocks after the EMR has been enabled (see Figure 79 (page 122) for
ODT timing diagrams).
Off-Chip Driver (OCD) Impedance Calibration
The OFF-CHIP DRIVER function is an optional DDR2 JEDEC feature not supported by
Micron and thereby must be set to the default state. Enabling OCD beyond the default
settings will alter the I/O drive characteristics and the timing and output I/O specifications will no longer be valid (see Initialization (page 81) for proper setting of OCD
defaults).
Posted CAS Additive Latency (AL)
Posted CAS additive latency (AL) is supported to make the command and data bus efficient for sustainable bandwidths in DDR2 SDRAM. Bits E3–E5 define the value of AL, as
shown in Figure 36. Bits E3–E5 allow the user to program the DDR2 SDRAM with an AL
of 0, 1, 2, 3, 4, 5, or 6 clocks. Reserved states should not be used as an unknown operation or incompatibility with future versions may result.
In this operation, the DDR2 SDRAM allows a READ or WRITE command to be issued
prior to tRCD (MIN) with the requirement that AL ≤ tRCD (MIN). A typical application
using this feature would set AL = tRCD (MIN) - 1 × tCK. The READ or WRITE command
is held for the time of the AL before it is issued internally to the DDR2 SDRAM device.
RL is controlled by the sum of AL and CL; RL = AL + CL. WRITE latency (WL) is equal to
RL minus one clock; WL = AL + CL - 1 × tCK. An example of RL is shown in Figure 37
(page 78). An example of a WL is shown in Figure 38 (page 78).
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Extended Mode Register (EMR)
Figure 37: READ Latency
CK#
T0
T1
T2
T3
T4
T5
T6
T7
T8
ACTIVE n
READ n
NOP
NOP
NOP
NOP
NOP
NOP
NOP
CK
Command
DQS, DQS#
tRCD (MIN)
DQ
AL = 2
DO
n
CL = 3
DO
n+1
DO
n+2
DO
n+3
RL = 5
Transitioning Data
Don’t Care
1. BL = 4.
2. Shown with nominal tAC, tDQSCK, and tDQSQ.
3. RL = AL + CL = 5.
Notes:
Figure 38: WRITE Latency
CK#
T0
T1
ACTIVE n
WRITE n
T2
T3
T4
T5
T6
T7
NOP
NOP
NOP
NOP
NOP
NOP
CK
Command
tRCD (MIN)
DQS, DQS#
AL = 2
CL - 1 = 2
DI
n
DQ
DI
n+1
DI
n+2
DI
n+3
WL = AL + CL - 1 = 4
Transitioning Data
Notes:
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Don’t Care
1. BL = 4.
2. CL = 3.
3. WL = AL + CL - 1 = 4.
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Extended Mode Register 2 (EMR2)
Extended Mode Register 2 (EMR2)
The extended mode register 2 (EMR2) controls functions beyond those controlled by
the mode register. Currently all bits in EMR2 are reserved, except for E7, which is used
in commercial or high-temperature operations, as shown in Figure 39. The EMR2 is programmed via the LM command and will retain the stored information until it is programmed again or until the device loses power. Reprogramming the EMR will not alter the
contents of the memory array, provided it is performed correctly.
Bit E7 (A7) must be programmed as “1” to provide a faster refresh rate on IT and AT
devices if TC exceeds 85°C.
EMR2 must be loaded when all banks are idle and no bursts are in progress, and the
controller must wait the specified time tMRD before initiating any subsequent operation. Violating either of these requirements could result in an unspecified operation.
Figure 39: EMR2 Definition
1
2
BA2 BA1 BA0 An A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2
16
0
E15 E14
Notes:
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15 14 n
MRS 0
12 11
0 0
10 9 8 7 6
0 0 SRT 0
0
5 4 3 2
0 0 0 0
A1 A0
1
0
0
0
Mode Register Set
E7
SRT Enable
Mode register (MR)
0
1X refresh rate (0°C to 85°C)
1
Extended mode register (EMR)
1
2X refresh rate (>85°C)
0
Extended mode register (EMR2)
1
Extended mode register (EMR3)
0
0
0
1
1
Address bus
Extended mode
register (Ex)
1. E16 (BA2) is only applicable for densities ≥1Gb, reserved for future use, and must be programmed to “0.”
2. Mode bits (En) with corresponding address balls (An) greater than E12 (A12) are reserved for future use and must be programmed to “0.”
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Extended Mode Register 3 (EMR3)
Extended Mode Register 3 (EMR3)
The extended mode register 3 (EMR3) controls functions beyond those controlled by
the mode register. Currently all bits in EMR3 are reserved, as shown in Figure 40. The
EMR3 is programmed via the LM command and will retain the stored information until
it is programmed again or until the device loses power. Reprogramming the EMR will
not alter the contents of the memory array, provided it is performed correctly.
EMR3 must be loaded when all banks are idle and no bursts are in progress, and the
controller must wait the specified time tMRD before initiating any subsequent operation. Violating either of these requirements could result in an unspecified operation.
Figure 40: EMR3 Definition
1
2
BA2 BA1 BA0 An A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2
16
15 14 n
12 11
10
0
MRS
0
0
E15 E14
Notes:
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0
0
9
0
8
0
7
0
6
0
5
0
4
0
3
0
2
0
A1 A0
1
0
0
0
Address bus
Extended mode
register (Ex)
Mode Register Set
0
0
Mode register (MR)
0
1
Extended mode register (EMR)
1
0
Extended mode register (EMR2)
1
1
Extended mode register (EMR3)
1. E16 (BA2) is only applicable for densities ≥1Gb, is reserved for future use, and must be
programmed to “0.”
2. Mode bits (En) with corresponding address balls (An) greater than E12 (A12) are reserved for future use and must be programmed to “0.”
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Initialization
Figure 41: DDR2 Power-Up and Initialization
DDR2 SDRAM must be powered up and initialized in a predefined manner. Operational procedures other than those specified may result in undefined operation. Figure 41 illustrates, and the notes outline, the sequence required for power-up and initialization.
VDD
VDDL
VDDQ
tVTD1
VTT1
VREF
T0
tCK
CK#
CK
tCL
LVCMOS
CKE low level2
Ta0
Tb0
Tc0
Td0
Te0
Tf0
Tg0
Th0
Ti0
Tj0
Tk0
Tl0
Tm0
NOP3
PRE
LM5
LM6
LM7
LM8
PRE9
REF10
REF10
LM11
LM12
LM13
Valid14
A10 = 1
Code
Code
Code
Code
A10 = 1
Code
Code
Code
Valid
tCL
SSTL_18 2
low level
ODT
81
Command
15
DM
15
High-Z
15
High-Z
DQS
DQ
Rtt
High-Z
T = 200µs (MIN)3
Power-up:
VDD and stable
clock (CK, CK#)
T = 400ns (MIN)4
tRPA
tMRD
EMR(2)
tMRD
EMR(3)
tMRD
tMRD
tRPA
tRFC
tRFC
tMRD
tMRD
tMRD
See no te 10
EMR
MR without
DLL RESET
EMR with
OCD default
EMR with
OCD exit
200 cycles of CK are required before a READ command can be issued
Normal
operation
MR with
DLL RESET
Indicates a Break in
Time Scale
Don’t care
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Initialization
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16
Address
2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Initialization
Notes:
1. Applying power; if CKE is maintained below 0.2 × VDDQ, outputs remain disabled. To
guarantee RTT (ODT resistance) is off, VREF must be valid and a low level must be applied
to the ODT ball (all other inputs may be undefined; I/Os and outputs must be less than
VDDQ during voltage ramp time to avoid DDR2 SDRAM device latch-up). VTT is not applied directly to the device; however, tVTD should be ≥0 to avoid device latch-up. At
least one of the following two sets of conditions (A or B) must be met to obtain a stable
supply state (stable supply defined as VDD, VDDL, VDDQ, VREF, and VTT are between their
minimum and maximum values as stated in (page 0 )):
A. Single power source: The VDD voltage ramp from 300mV to VDD,min must take no longer than 200ms; during the VDD voltage ramp, |VDD - VDDQ| ≤ 0.3V. Once supply voltage
ramping is complete (when VDDQ crosses VDD,min), specifications apply.
• VDD, VDDL, and VDDQ are driven from a single power converter output
• VTT is limited to 0.95V MAX
• VREF tracks VDDQ/2; VREF must be within ±0.3V with respect to VDDQ/2 during supply
ramp time; does not need to be satisfied when ramping power down
• VDDQ ≥ VREF at all times
B. Multiple power sources: VDD ≥ VDDL ≥ VDDQ must be maintained during supply voltage
ramping, for both AC and DC levels, until supply voltage ramping completes (VDDQ
crosses VDD,min). Once supply voltage ramping is complete, specifications apply.
2.
3.
4.
5.
6.
7.
8.
9.
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• Apply VDD and VDDL before or at the same time as VDDQ; VDD/VDDL voltage ramp time
must be ≤ 200ms from when VDD ramps from 300mV to VDD,min
• Apply VDDQ before or at the same time as VTT; the VDDQ voltage ramp time from when
VDD,min is achieved to when VDDQ,min is achieved must be ≤ 500ms; while VDD is ramping, current can be supplied from VDD through the device to VDDQ
• VREF must track VDDQ/2; VREF must be within ±0.3V with respect to VDDQ/2 during supply ramp time; VDDQ ≥ VREF must be met at all times; does not need to be satisfied
when ramping power down
• Apply VTT; the VTT voltage ramp time from when VDDQ,min is achieved to when VTT,min
is achieved must be no greater than 500ms
CKE requires LVCMOS input levels prior to state T0 to ensure DQs are High-Z during device power-up prior to VREF being stable. After state T0, CKE is required to have SSTL_18
input levels. Once CKE transitions to a high level, it must stay HIGH for the duration of
the initialization sequence.
For a minimum of 200µs after stable power and clock (CK, CK#), apply NOP or DESELECT
commands, then take CKE HIGH.
Wait a minimum of 400ns then issue a PRECHARGE ALL command.
Issue a LOAD MODE command to the EMR(2). To issue an EMR(2) command, provide
LOW to BA0, and provide HIGH to BA1; set register E7 to “0” or “1” to select appropriate self refresh rate; remaining EMR(2) bits must be “0” (see Extended Mode Register 2
(EMR2) (page 79) for all EMR(2) requirements).
Issue a LOAD MODE command to the EMR(3). To issue an EMR(3) command, provide
HIGH to BA0 and BA1; remaining EMR(3) bits must be “0.” Extended Mode Register 3
(EMR3) for all EMR(3) requirements.
Issue a LOAD MODE command to the EMR to enable DLL. To issue a DLL ENABLE command, provide LOW to BA1 and A0; provide HIGH to BA0; bits E7, E8, and E9 can be set
to “0” or “1;” Micron recommends setting them to “0;” remaining EMR bits must be
“0.” Extended Mode Register (EMR) (page 75) for all EMR requirements.
Issue a LOAD MODE command to the MR for DLL RESET. 200 cycles of clock input is required to lock the DLL. To issue a DLL RESET, provide HIGH to A8 and provide LOW to
BA1 and BA0; CKE must be HIGH the entire time the DLL is resetting; remaining MR bits
must be “0.” Mode Register (MR) (page 70) for all MR requirements.
Issue PRECHARGE ALL command.
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Initialization
10. Issue two or more REFRESH commands.
11. Issue a LOAD MODE command to the MR with LOW to A8 to initialize device operation
(that is, to program operating parameters without resetting the DLL). To access the MR,
set BA0 and BA1 LOW; remaining MR bits must be set to desired settings. Mode Register
(MR) (page 70) for all MR requirements.
12. Issue a LOAD MODE command to the EMR to enable OCD default by setting bits E7, E8,
and E9 to “1,” and then setting all other desired parameters. To access the EMR, set BA0
HIGH and BA1 LOW (see Extended Mode Register (EMR) (page 75) for all EMR requirements.
13. Issue a LOAD MODE command to the EMR to enable OCD exit by setting bits E7, E8, and
E9 to “0,” and then setting all other desired parameters. To access the extended mode
registers, EMR, set BA0 HIGH and BA1 LOW for all EMR requirements.
14. The DDR2 SDRAM is now initialized and ready for normal operation 200 clock cycles after the DLL RESET at Tf0.
15. DM represents DM for the x4, x8 configurations and UDM, LDM for the x16 configuration; DQS represents DQS, DQS#, UDQS, UDQS#, LDQS, LDQS#, RDQS, RDQS# for the
appropriate configuration (x4, x8, x16); DQ represents DQ0–DQ3 for x4, DQ–DQ7 for x8
and DQ0–DQ15 for x16.
16. A10 = PRECHARGE ALL, CODE = desired values for mode registers (bank addresses are
required to be decoded).
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ACTIVATE
ACTIVATE
Before any READ or WRITE commands can be issued to a bank within the DDR2
SDRAM, a row in that bank must be opened (activated), even when additive latency is
used. This is accomplished via the ACTIVATE command, which selects both the bank
and the row to be activated.
After a row is opened with an ACTIVATE command, a READ or WRITE command may
be issued to that row subject to the tRCD specification. tRCD (MIN) should be divided
by the clock period and rounded up to the next whole number to determine the earliest
clock edge after the ACTIVATE command on which a READ or WRITE command can be
entered. The same procedure is used to convert other specification limits from time
units to clock cycles. For example, a tRCD (MIN) specification of 20ns with a 266 MHz
clock (tCK = 3.75ns) results in 5.3 clocks, rounded up to 6. This is shown in Figure 42,
which covers any case where 5 < tRCD (MIN)/tCK ≤ 6. Figure 42 also shows the case for
tRRD where 2 < tRRD (MIN)/tCK ≤ 3.
Figure 42: Example: Meeting tRRD (MIN) and tRCD (MIN)
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
Command
ACT
NOP
NOP
ACT
NOP
NOP
NOP
NOP
NOP
RD/WR
Address
Row
CK#
CK
Bank address
Row
Bank x
Bank y
tRRD
Row
Col
Bank z
Bank y
tRRD
tRCD
Don’t Care
A subsequent ACTIVATE command to a different row in the same bank can only be issued after the previous active row has been closed (precharged). The minimum time
interval between successive ACTIVATE commands to the same bank is defined by tRC.
A subsequent ACTIVATE command to another bank can be issued while the first bank is
being accessed, which results in a reduction of total row-access overhead. The minimum time interval between successive ACTIVATE commands to different banks is
defined by tRRD.
DDR2 devices with 8 banks (1Gb or larger) have an additional requirement: tFAW. This
requires no more than four ACTIVATE commands may be issued in any given tFAW
(MIN) period, as shown in Figure 43 (page 85).
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ACTIVATE
Figure 43: Multibank Activate Restriction
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
T10
Command
ACT
READ
ACT
READ
ACT
READ
ACT
READ
NOP
NOP
ACT
Address
Row
Col
Row
Col
Row
Col
Row
Col
Row
Bank a
Bank b
Bank c
Bank c
Bank d
Bank d
Bank e
CK#
CK
Bank address
Bank a
tRRD (MIN)
Bank b
tFAW (MIN)
Don’t Care
Note:
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1. DDR2-533 (-37E, x4 or x8), tCK = 3.75ns, BL = 4, AL = 3, CL = 4, tRRD (MIN) = 7.5ns,
tFAW (MIN) = 37.5ns.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
READ
READ
READ bursts are initiated with a READ command. The starting column and bank addresses are provided with the READ command, and auto precharge is either enabled or
disabled for that burst access. If auto precharge is enabled, the row being accessed is
automatically precharged at the completion of the burst. If auto precharge is disabled,
the row will be left open after the completion of the burst.
During READ bursts, the valid data-out element from the starting column address will
be available READ latency (RL) clocks later. RL is defined as the sum of AL and CL:
RL = AL + CL. The value for AL and CL are programmable via the MR and EMR commands, respectively. Each subsequent data-out element will be valid nominally at the
next positive or negative clock edge (at the next crossing of CK and CK#). Figure 44
(page 87) shows examples of RL based on different AL and CL settings.
DQS/DQS# is driven by the DDR2 SDRAM along with output data. The initial LOW state
on DQS and the HIGH state on DQS# are known as the read preamble (tRPRE). The
LOW state on DQS and the HIGH state on DQS# coincident with the last data-out element are known as the read postamble (tRPST).
Upon completion of a burst, assuming no other commands have been initiated, the DQ
will go High-Z. A detailed explanation of tDQSQ (valid data-out skew), tQH (data-out
window hold), and the valid data window are depicted in Figure 53 (page 95) and Figure 54 (page 96). A detailed explanation of tDQSCK (DQS transition skew to CK) and
tAC (data-out transition skew to CK) is shown in Figure 55 (page 97).
Data from any READ burst may be concatenated with data from a subsequent READ
command to provide a continuous flow of data. The first data element from the new
burst follows the last element of a completed burst. The new READ command should
be issued x cycles after the first READ command, where x equals BL/2 cycles (see Figure 45 (page 88)).
Nonconsecutive read data is illustrated in Figure 46 (page 89). Full-speed random
read accesses within a page (or pages) can be performed. DDR2 SDRAM supports the
use of concurrent auto precharge timing (see Table 41 (page 92)).
DDR2 SDRAM does not allow interrupting or truncating of any READ burst using BL = 4
operations. Once the BL = 4 READ command is registered, it must be allowed to complete the entire READ burst. However, a READ (with auto precharge disabled) using BL
= 8 operation may be interrupted and truncated only by another READ burst as long as
the interruption occurs on a 4-bit boundary due to the 4n prefetch architecture of
DDR2 SDRAM. As shown in Figure 47 (page 90), READ burst BL = 8 operations may
not be interrupted or truncated with any other command except another READ command.
Data from any READ burst must be completed before a subsequent WRITE burst is allowed. An example of a READ burst followed by a WRITE burst is shown in Figure 48
(page 90). The tDQSS (NOM) case is shown (tDQSS [MIN] and tDQSS [MAX] are defined in Figure 56 (page 99)).
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READ
Figure 44: READ Latency
CK#
T0
T1
T2
T3
READ
NOP
NOP
NOP
T3n
T4
T4n
T5
CK
Command
Address
NOP
NOP
Bank a,
Col n
RL = 3 (AL = 0, CL = 3)
DQS, DQS#
DO
n
DQ
CK#
T0
T1
T2
T3
T4
T4n
READ
NOP
NOP
NOP
NOP
T5
T5n
CK
Command
Address
NOP
Bank a,
Col n
AL = 1
CL = 3
RL = 4 (AL = 1 + CL = 3)
DQS, DQS#
DO
n
DQ
CK#
T0
T1
T2
T3
READ
NOP
NOP
NOP
T3n
T4
T4n
T5
CK
Command
Address
NOP
NOP
Bank a,
Col n
RL = 4 (AL = 0, CL = 4)
DQS, DQS#
DO
n
DQ
Transitioning Data
Notes:
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Don’t Care
1. DO n = data-out from column n.
2. BL = 4.
3. Three subsequent elements of data-out appear in the programmed order following
DO n.
4. Shown with nominal tAC, tDQSCK, and tDQSQ.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
READ
Figure 45: Consecutive READ Bursts
T0
T1
T2
T3
Command
READ
NOP
READ
NOP
Address
Bank,
Col n
CK#
T3n
T4
T4n
T5n
T5
T6n
T6
CK
NOP
NOP
NOP
Bank,
Col b
tCCD
RL = 3
DQS, DQS#
DO
n
DQ
T0
T1
T2
Command
READ
NOP
READ
Address
Bank,
Col n
CK#
T2n
T3
DO
b
T3n
T4
T4n
T5
T5n
T6n
T6
CK
NOP
NOP
NOP
NOP
Bank,
Col b
tCCD
RL = 4
DQS, DQS#
DO
n
DQ
Transitioning Data
Notes:
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DO
b
Don’t Care
1. DO n (or b) = data-out from column n (or column b).
2. BL = 4.
3. Three subsequent elements of data-out appear in the programmed order following
DO n.
4. Three subsequent elements of data-out appear in the programmed order following
DO b.
5. Shown with nominal tAC, tDQSCK, and tDQSQ.
6. Example applies only when READ commands are issued to same device.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
READ
Figure 46: Nonconsecutive READ Bursts
CK#
CK
Command
T0
T1
T2
T3
T3n
READ
NOP
NOP
READ
Address
Bank,
Col n
T4
T4n
NOP
T5
T6
T6n
NOP
NOP
T7
T7n
NOP
T8
NOP
Bank,
Col b
CL = 3
DQS, DQS#
DO
n
DQ
DO
b
T4n
T0
T1
T2
T3
T4
Command
READ
NOP
NOP
READ
NOP
Address
Bank,
Col n
CK#
CK
T5
NOP
T5n
T6
T7
T7n
NOP
NOP
T8
NOP
Bank,
Col b
CL = 4
DQS, DQS#
DO
n
DQ
DO
b
Transitioning Data
Notes:
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Don’t Care
1. DO n (or b) = data-out from column n (or column b).
2. BL = 4.
3. Three subsequent elements of data-out appear in the programmed order following
DO n.
4. Three subsequent elements of data-out appear in the programmed order following
DO b.
5. Shown with nominal tAC, tDQSCK, and tDQSQ.
6. Example applies when READ commands are issued to different devices or nonconsecutive READs.
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READ
Figure 47: READ Interrupted by READ
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
Command
READ1
NOP2
READ3
NOP2
Valid
Valid
Valid
Valid
Valid
Valid
Address
Valid4
CK#
CK
Valid4
Valid5
A10
DQS, DQS#
DO
DQ
DO
DO
DO
DO
DO
DO
DO
DO
DO
DO
DO
CL = 3 (AL = 0)
tCCD
CL = 3 (AL = 0)
Transitioning Data
Notes:
Don’t Care
1. BL = 8 required; auto precharge must be disabled (A10 = LOW).
2. NOP or COMMAND INHIBIT commands are valid. PRECHARGE command cannot be issued to banks used for READs at T0 and T2.
3. Interrupting READ command must be issued exactly 2 × tCK from previous READ.
4. READ command can be issued to any valid bank and row address (READ command at T0
and T2 can be either same bank or different bank).
5. Auto precharge can be either enabled (A10 = HIGH) or disabled (A10 = LOW) by the interrupting READ command.
6. Example shown uses AL = 0; CL = 3, BL = 8, shown with nominal tAC, tDQSCK, and tDQSQ.
Figure 48: READ-to-WRITE
CK#
CK
Command
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
T10
T11
ACT n
READ n
NOP
NOP
NOP
WRITE
NOP
NOP
NOP
NOP
NOP
NOP
DQS, DQS#
tRCD = 3
WL = RL - 1 = 4
DO
n
DQ
AL = 2
CL = 3
DO
n+1
DO
n+2
DO
n+3
DI
n
DI
n+1
DI
n+2
DI
n+3
RL = 5
Transitioning Data
Notes:
Don’t Care
1. BL = 4; CL = 3; AL = 2.
2. Shown with nominal tAC, tDQSCK, and tDQSQ.
READ with Precharge
A READ burst may be followed by a PRECHARGE command to the same bank, provided
auto precharge is not activated. The minimum READ-to-PRECHARGE command spacing to the same bank has two requirements that must be satisfied: AL + BL/2 clocks and
tRTP. tRTP is the minimum time from the rising clock edge that initiates the last 4-bit
prefetch of a READ command to the PRECHARGE command. For BL = 4, this is the time
from the actual READ (AL after the READ command) to PRECHARGE command. For
BL = 8, this is the time from AL + 2 × CK after the READ-to-PRECHARGE command.
Following the PRECHARGE command, a subsequent command to the same bank canPDF: 09005aef844ec98c
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
READ
not be issued until tRP is met. However, part of the row precharge time is hidden during
the access of the last data elements.
Examples of READ-to-PRECHARGE for BL = 4 are shown in Figure 49 and in Figure 50
for BL = 8. The delay from READ-to-PRECHARGE period to the same bank is AL + BL/
2 - 2CK + MAX (tRTP/tCK or 2 × CK) where MAX means the larger of the two.
Figure 49: READ-to-PRECHARGE – BL = 4
CK#
CK
Command
T0
4-bit
prefetch
T1
T2
T3
T4
T5
T6
T7
NOP
NOP
PRE
NOP
NOP
ACT
NOP
READ
AL + BL/2 - 2CK + MAX (tRTP/tCK or 2CK)
Address
Bank a
Bank a
A10
Bank a
Valid
AL = 1
Valid
CL = 3
DQS, DQS#
≥tRTP (MIN)
DQ
DO
DO
DO
DO
≥tRP (MIN)
≥tRAS (MIN)
≥tRC (MIN)
Transitioning Data
Notes:
Don’t Care
1. RL = 4 (AL = 1, CL = 3); BL = 4.
2. tRTP ≥ 2 clocks.
3. Shown with nominal tAC, tDQSCK, and tDQSQ.
Figure 50: READ-to-PRECHARGE – BL = 8
CK#
CK
Command
T0
First 4-bit
prefetch
T1
READ
NOP
T2
Second 4-bit
prefetch
T3
T4
T5
T6
T7
T8
NOP
NOP
NOP
PRE
NOP
NOP
ACT
AL + BL/2 - 2CK + MAX (tRTP/tCK or 2CK)
Address
Bank a
A10
AL = 1
Bank a
Bank a
Valid
Valid
CL = 3
DQS, DQS#
DQ
DO
DO
≥tRTP (MIN)
DO
DO
DO
DO
DO
DO
≥tRP (MIN)
≥tRAS (MIN)
≥tRC (MIN)
Transitioning Data
Notes:
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Don’t Care
1. RL = 4 (AL = 1, CL = 3); BL = 8.
2. tRTP ≥ 2 clocks.
3. Shown with nominal tAC, tDQSCK, and tDQSQ.
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READ
READ with Auto Precharge
If A10 is high when a READ command is issued, the READ with auto precharge function
is engaged. The DDR2 SDRAM starts an auto precharge operation on the rising clock
edge that is AL + (BL/2) cycles later than the read with auto precharge command provided tRAS (MIN) and tRTP are satisfied. If tRAS (MIN) is not satisfied at this rising clock
edge, the start point of the auto precharge operation will be delayed until tRAS (MIN) is
satisfied. If tRTP (MIN) is not satisfied at this rising clock edge, the start point of the
auto precharge operation will be delayed until tRTP (MIN) is satisfied. When the internal precharge is pushed out by tRTP, tRP starts at the point where the internal precharge happens (not at the next rising clock edge after this event).
When BL = 4, the minimum time from READ with auto precharge to the next ACTIVATE
command is AL + (tRTP + tRP)/tCK. When BL = 8, the minimum time from READ with
auto precharge to the next ACTIVATE command is AL + 2 clocks + (tRTP + tRP)/tCK. The
term (tRTP + tRP)/tCK is always rounded up to the next integer. A general purpose equation can also be used: AL + BL/2 - 2CK + (tRTP + tRP)/tCK. In any event, the internal
precharge does not start earlier than two clocks after the last 4-bit prefetch.
READ with auto precharge command may be applied to one bank while another bank is
operational. This is referred to as concurrent auto precharge operation, as noted in Table 41. Examples of READ with precharge and READ with auto precharge with applicable timing requirements are shown in Figure 51 (page 93) and Figure 52 (page 94),
respectively.
Table 41: READ Using Concurrent Auto Precharge
From Command (Bank n)
To Command (Bank m)
Minimum Delay
(with Concurrent Auto Precharge)
Units
READ with auto precharge
READ or READ with auto precharge
BL/2
tCK
WRITE or WRITE with auto precharge
(BL/2) + 2
tCK
PRECHARGE or ACTIVATE
1
tCK
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
READ
Figure 51: Bank Read – Without Auto Precharge
T1
T0
CK#
CK
T2
tCH
tCK
T3
T4
NOP1
READ2
T5
T6
T7
T7n
NOP1
PRE3
NOP1
T8
T9
T8n
tCL
CKE
Command
NOP1
ACT
NOP1
NOP1
ACT
tRTP4
Address
RA
Col n
A10
RA
5
RA
All banks
RA
One bank
Bank address
Bank x
Bank x6
Bank x
tRCD
Bank x
CL = 3
tRP
tRAS3
tRC
DM
Case 1: tAC (MIN) and tDQSCK (MIN)
7
DQS, DQS#
tDQSCK (MIN)
tRPRE
tLZ (MIN)
DO
n
DQ8
tLZ (MIN)
Case 2: tAC (MAX) and tDQSCK (MAX)
7
DQS, DQS#
tRPRE
tAC (MIN)
tDQSCK (MAX)
tHZ (MIN)
tRPST
7
tLZ (MAX)
DQ8
DO
n
tLZ (MIN)
tAC (MAX)
Transitioning Data
Notes:
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
tRPST
7
tHZ (MAX)
Don’t Care
1. NOP commands are shown for ease of illustration; other commands may be valid at
these times.
2. BL = 4 and AL = 0 in the case shown.
3. The PRECHARGE command can only be applied at T6 if tRAS (MIN) is met.
4. READ-to-PRECHARGE = AL + BL/2 - 2CK + MAX (tRTP/tCK or 2CK).
5. Disable auto precharge.
6. “Don’t Care” if A10 is HIGH at T5.
7. I/O balls, when entering or exiting High-Z, are not referenced to a specific voltage level,
but to when the device begins to drive or no longer drives, respectively.
8. DO n = data-out from column n; subsequent elements are applied in the programmed
order.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
READ
Figure 52: Bank Read – with Auto Precharge
CK#
T1
T0
CK
T2
tCK
tCH
T3
T4
T5
T6
T7
T7n
READ2,3
NOP1
NOP1
NOP1
NOP1
T8
T8n
tCL
CKE
Command1
NOP1
ACT
NOP1
ACT
Col n
RA
Address
NOP1
RA
4
A10
Bank address
RA
RA
Bank x
Bank x
Bank x
AL = 1
CL = 3
tRTP
tRCD
tRP
tRAS
tRC
DM
tDQSCK (MIN)
Case 1: tAC (MIN) and tDQSCK (MIN)
5
DQS, DQS#
tRPRE
tRPST
5
tLZ (MIN)
DO
n
DQ6
tLZ (MIN)
Case 2: tAC (MAX) and tDQSCK (MAX)
5
tAC (MIN)
tRPRE
tDQSCK (MAX)
tHZ (MIN)
tRPST
5
DQS, DQS#
tLZ (MAX)
DQ6
DO
n
4-bit
prefetch
t
Internal LZ (MAX)
precharge
tAC (MAX)
Transitioning Data
Notes:
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
tHZ (MAX)
Don’t Care
1. NOP commands are shown for ease of illustration; other commands may be valid at
these times.
2. BL = 4, RL = 4 (AL = 1, CL = 3) in the case shown.
3. The DDR2 SDRAM internally delays auto precharge until both tRAS (MIN) and tRTP (MIN)
have been satisfied.
4. Enable auto precharge.
5. I/O balls, when entering or exiting High-Z, are not referenced to a specific voltage level,
but to when the device begins to drive or no longer drives, respectively.
6. DO n = data-out from column n; subsequent elements are applied in the programmed
order.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
READ
Figure 53: x4, x8 Data Output Timing – tDQSQ, tQH, and Data Valid Window
T1
T2
T2n
T3
T3n
T4
CK#
CK
tHP1
tHP1
tHP1
tHP1
tDQSQ2
tDQSQ2
tQH5
tQH5
tQHS
tHP1
tHP1
tDQSQ2
tDQSQ2
DQS#
DQS3
DQ (last data valid)
DQ4
DQ4
DQ4
DQ4
DQ4
DQ4
DQ (first data no longer valid)
tQH5
tQHS
tQH5
tQHS
tQHS
DQ (last data valid)
T2
T2n
T3
T3n
DQ (first data no longer valid)
T2
T2n
T3
T3n
All DQs and DQS collectively6
T2
T2n
T3
T3n
Data
valid
window
Data
valid
window
Data
valid
window
Data
valid
window
Earliest signal transition
Latest signal transition
Notes:
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1. tHP is the lesser of tCL or tCH clock transitions collectively when a bank is active.
2. tDQSQ is derived at each DQS clock edge, is not cumulative over time, begins with DQS
transitions, and ends with the last valid transition of DQ.
3. DQ transitioning after the DQS transition defines the tDQSQ window. DQS transitions at
T2 and at T2n are “early DQS,” at T3 are “nominal DQS,” and at T3n are “late DQS.”
4. DQ0, DQ1, DQ2, DQ3 for x4 or DQ0–DQ7 for x8.
5. tQH is derived from tHP: tQH = tHP - tQHS.
6. The data valid window is derived for each DQS transition and is defined as tQH - tDQSQ.
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READ
Figure 54: x16 Data Output Timing – tDQSQ, tQH, and Data Valid Window
CK#
T1
T2
T2n
T3
T3n
T4
CK
tHP1
tHP1
tHP1
tDQSQ2
tHP1
tHP1
tHP1
tDQSQ2
tDQSQ2
tDQSQ2
tQH5
tQHS
tQH5
tQHS
tQH5
tQHS
LDSQ#
LDQS3
Lower Byte
DQ (last data valid)4
DQ4
DQ4
DQ4
DQ4
DQ4
DQ4
DQ (first data no longer valid)4
tQH5
tQHS
DQ (last data valid)4
T2
T2n
T3
T3n
DQ (first data no longer valid)4
T2
T2n
T3
T3n
DQ0–DQ7 and LDQS collectively6
T2
T2n
T3
T3n
Data valid
window
Data valid
window
Data valid
window
tDQSQ2
Data valid
window
tDQSQ2
tDQSQ2
tDQSQ2
tQH5
tQHS
tQH5
tQHS
tQH5
tQHS
UDQS#
UDQS3
Upper Byte
DQ (last data valid)7
DQ7
DQ7
DQ7
DQ7
DQ7
DQ7
DQ (first data no longer valid)7
tQH5
DQ (last data valid)7
T2
T2n
DQ (first data no longer valid)7
T2
T2n
DQ8–DQ15 and UDQS collectively6
T2
T2n
Data valid
window
Notes:
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Data valid
window
T3
T3
tQHS
T3n
T3n
T3
T3n
Data valid
window
Data valid
window
1. tHP is the lesser of tCL or tCH clock transitions collectively when a bank is active.
2. tDQSQ is derived at each DQS clock edge, is not cumulative over time, begins with DQS
transitions, and ends with the last valid transition of DQ.
3. DQ transitioning after the DQS transitions define the tDQSQ window. LDQS defines the
lower byte, and UDQS defines the upper byte.
4. DQ0, DQ1, DQ2, DQ3, DQ4, DQ5, DQ6, or DQ7.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
WRITE
5. tQH is derived from tHP: tQH = tHP - tQHS.
6. The data valid window is derived for each DQS transition and is tQH - tDQSQ.
7. DQ8, DQ9, DQ10, D11, DQ12, DQ13, DQ14, or DQ15.
Figure 55: Data Output Timing – tAC and tDQSCK
CK#
T01
T1
T2
T3
T3n
T4
T4n
T5
T5n
T6
T6n
T7
CK
tLZ (MIN)
tRPRE
tDQSCK2 (MAX)
tDQSCK2 (MIN)
tHZ (MAX)
tRPST
DQS#/DQS or
LDQS#/LDQS/UDQ#/UDQS3
DQ (last data valid)
DQ (first data valid)
All DQs collectively4
T3
tLZ (MIN)
Notes:
T3n
T4
T4n
T3
T3n
T4
T4n
T3
T3n
T4
T4n
tAC5 (MIN)
T5
T5n
T6
T6n
T5
T5n
T6
T6n
T5
T5n
T6
T6n
tAC5 (MAX)
tHZ (MAX)
1. READ command with CL = 3, AL = 0 issued at T0.
2. tDQSCK is the DQS output window relative to CK and is the long-term component of
DQS skew.
3. DQ transitioning after DQS transitions define tDQSQ window.
4. All DQ must transition by tDQSQ after DQS transitions, regardless of tAC.
5. tAC is the DQ output window relative to CK and is the “long term” component of DQ
skew.
6. tLZ (MIN) and tAC (MIN) are the first valid signal transitions.
7. tHZ (MAX) and tAC (MAX) are the latest valid signal transitions.
8. I/O balls, when entering or exiting High-Z, are not referenced to a specific voltage level,
but to when the device begins to drive or no longer drives, respectively.
WRITE
WRITE bursts are initiated with a WRITE command. DDR2 SDRAM uses WL equal to RL
minus one clock cycle (WL = RL - 1CK) (see READ (page 69)). The starting column and
bank addresses are provided with the WRITE command, and auto precharge is either
enabled or disabled for that access. If auto precharge is enabled, the row being accessed
is precharged at the completion of the burst.
Note:
For the WRITE commands used in the following illustrations, auto precharge is disabled.
During WRITE bursts, the first valid data-in element will be registered on the first rising
edge of DQS following the WRITE command, and subsequent data elements will be registered on successive edges of DQS. The LOW state on DQS between the WRITE command and the first rising edge is known as the write preamble; the LOW state on DQS
following the last data-in element is known as the write postamble.
The time between the WRITE command and the first rising DQS edge is WL ±tDQSS.
Subsequent DQS positive rising edges are timed, relative to the associated clock edge,
as ±tDQSS. tDQSS is specified with a relatively wide range (25% of one clock cycle). All of
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
WRITE
the WRITE diagrams show the nominal case, and where the two extreme cases (tDQSS
[MIN] and tDQSS [MAX]) might not be intuitive, they have also been included. Figure 56
(page 99) shows the nominal case and the extremes of tDQSS for BL = 4. Upon completion of a burst, assuming no other commands have been initiated, the DQ will remain
High-Z and any additional input data will be ignored.
Data for any WRITE burst may be concatenated with a subsequent WRITE command to
provide continuous flow of input data. The first data element from the new burst is applied after the last element of a completed burst. The new WRITE command should be
issued x cycles after the first WRITE command, where x equals BL/2.
Figure 57 (page 100) shows concatenated bursts of BL = 4 and how full-speed random
write accesses within a page or pages can be performed. An example of nonconsecutive
WRITEs is shown in Figure 58 (page 100). DDR2 SDRAM supports concurrent auto precharge options, as shown in Table 42.
DDR2 SDRAM does not allow interrupting or truncating any WRITE burst using BL = 4
operation. Once the BL = 4 WRITE command is registered, it must be allowed to complete the entire WRITE burst cycle. However, a WRITE BL = 8 operation (with auto
precharge disabled) might be interrupted and truncated only by another WRITE burst
as long as the interruption occurs on a 4-bit boundary due to the 4n-prefetch architecture of DDR2 SDRAM. WRITE burst BL = 8 operations may not be interrupted or
truncated with any command except another WRITE command, as shown in Figure 59
(page 101).
Data for any WRITE burst may be followed by a subsequent READ command. To follow
a WRITE, tWTR should be met, as shown in Figure 60 (page 102). The number of clock
cycles required to meet tWTR is either 2 or tWTR/tCK, whichever is greater. Data for any
WRITE burst may be followed by a subsequent PRECHARGE command. tWR must be
met, as shown in Figure 61 (page 103). tWR starts at the end of the data burst, regardless of the data mask condition.
Table 42: WRITE Using Concurrent Auto Precharge
From Command
(Bank n)
WRITE with auto precharge
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To Command
(Bank m)
Minimum Delay
(with Concurrent Auto Precharge)
READ or READ with auto precharge
(CL - 1) + (BL/2) +
tWTR
Units
tCK
WRITE or WRITE with auto precharge
(BL/2)
tCK
PRECHARGE or ACTIVATE
1
tCK
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
WRITE
Figure 56: Write Burst
T0
T1
T2
Command
WRITE
NOP
NOP
Address
Bank a,
Col b
CK#
T2n
T3
T3n
T4
CK
tDQSS (NOM)
NOP
WL ± tDQSS
NOP
5
DQS, DQS#
DI
b
DQ
DM
tDQSS (MIN)
tDQSS5
WL - tDQSS
DQS, DQS#
DI
b
DQ
DM
tDQSS (MAX)
WL + tDQSS
tDQSS5
DQS, DQS#
DI
b
DQ
DM
Transitioning Data
Notes:
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Don’t Care
1. Subsequent rising DQS signals must align to the clock within tDQSS.
2. DI b = data-in for column b.
3. Three subsequent elements of data-in are applied in the programmed order following
DI b.
4. Shown with BL = 4, AL = 0, CL = 3; thus, WL = 2.
5. A10 is LOW with the WRITE command (auto precharge is disabled).
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
WRITE
Figure 57: Consecutive WRITE-to-WRITE
CK#
T0
T1
WRITE
NOP
T1n
T2
T2n
T3
T3n
T4
T4n
T5
T5n
T6
CK
Command
WRITE
NOP
NOP
NOP
1
1
NOP
tCCD
WL = 2
WL = 2
Address
Bank,
Col b
tDQSS (NOM)
Bank,
Col n
WL ± tDQSS
1
DQS, DQS#
DI
b
DQ
DI
n
DM
Transitioning Data
Notes:
Don’t Care
1. Subsequent rising DQS signals must align to the clock within tDQSS.
2. DI b, etc. = data-in for column b, etc.
3. Three subsequent elements of data-in are applied in the programmed order following
DI b.
4. Three subsequent elements of data-in are applied in the programmed order following
DI n.
5. Shown with BL = 4, AL = 0, CL = 3; thus, WL = 2.
6. Each WRITE command may be to any bank.
Figure 58: Nonconsecutive WRITE-to-WRITE
CK#
T0
T1
T2
NOP
NOP
T2n
T3
T3n
T4
T4n
T5
T5n
T6
T6n
CK
Command
WRITE
WRITE
Address
tDQSS (NOM)
NOP
NOP
NOP
1
1
WL = 2
WL = 2
Bank,
Col b
Bank,
Col n
WL ± tDQSS
1
DQS, DQS#
DQ
DI
b
DI
n
DM
Transitioning Data
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Don’t Care
1. Subsequent rising DQS signals must align to the clock within tDQSS.
2. DI b (or n), etc. = data-in for column b (or column n).
3. Three subsequent elements of data-in are applied in the programmed order following
DI b.
4. Three subsequent elements of data-in are applied in the programmed order following
DI n.
5. Shown with BL = 4, AL = 0, CL = 3; thus, WL = 2.
6. Each WRITE command may be to any bank.
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WRITE
Figure 59: WRITE Interrupted by WRITE
CK#
CK
Command
Address
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
WRITE1 a
NOP2
WRITE3 b
NOP2
NOP2
NOP2
NOP2
Valid4
Valid4
Valid4
Valid5
Valid5
Valid6
A10
7
DQS, DQS#
DI
a
DQ
DI
a+1
7
DI
a+2
DI
a+3
DI
b
7
DI
b+1
DI
b+2
7
DI
b+3
7
DI
b+4
DI
b+5
DI
b+6
DI
b+7
WL = 3
2-clock requirement
WL = 3
Transitioning Data
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Don’t Care
1. BL = 8 required and auto precharge must be disabled (A10 = LOW).
2. The NOP or COMMAND INHIBIT commands are valid. The PRECHARGE command cannot
be issued to banks used for WRITEs at T0 and T2.
3. The interrupting WRITE command must be issued exactly 2 × tCK from previous WRITE.
4. The earliest WRITE-to-PRECHARGE timing for WRITE at T0 is WL + BL/2 + tWR where tWR
starts with T7 and not T5 (because BL = 8 from MR and not the truncated length).
5. The WRITE command can be issued to any valid bank and row address (WRITE command
at T0 and T2 can be either same bank or different bank).
6. Auto precharge can be either enabled (A10 = HIGH) or disabled (A10 = LOW) by the interrupting WRITE command.
7. Subsequent rising DQS signals must align to the clock within tDQSS.
8. Example shown uses AL = 0; CL = 4, BL = 8.
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WRITE
Figure 60: WRITE-to-READ
CK#
T0
T1
T2
WRITE
NOP
NOP
T2n
T3
T3n
T4
T5
T6
T7
T8
NOP
READ
NOP
NOP
T9
T9n
CK
Command
NOP
NOP
NOP
tWTR1
Address
Bank a,
Col b
tDQSS (NOM)
Bank a,
Col n
WL ± tDQSS
CL = 3
2
DQS, DQS#
DI
b
DQ
DI
DM
tDQSS (MIN)
WL - tDQSS
CL = 3
2
DQS, DQS#
DI
b
DQ
DI
DM
tDQSS (MAX)
WL + tDQSS
CL = 3
2
DQS, DQS#
DI
b
DQ
DI
DM
Transitioning Data
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Don’t Care
1. tWTR is required for any READ following a WRITE to the same device, but it is not required between module ranks.
2. Subsequent rising DQS signals must align to the clock within tDQSS.
3. DI b = data-in for column b; DO n = data-out from column n.
4. BL = 4, AL = 0, CL = 3; thus, WL = 2.
5. One subsequent element of data-in is applied in the programmed order following DI b.
6. tWTR is referenced from the first positive CK edge after the last data-in pair.
7. A10 is LOW with the WRITE command (auto precharge is disabled).
8. The number of clock cycles required to meet tWTR is either 2 or tWTR/tCK, whichever is
greater.
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WRITE
Figure 61: WRITE-to-PRECHARGE
CK#
T0
T1
T2
WRITE
NOP
NOP
T2n
T3
T3n
T4
T5
NOP
NOP
T6
T7
NOP
PRE
CK
Command
NOP
tWR
Address
Bank a,
Col b
tDQSS (NOM)
tRP
Bank,
(a or all)
WL + tDQSS
1
DQS#
DQS
DI
b
DQ
DM
tDQSS (MIN)
WL - tDQSS
1
DQS#
DQS
DI
b
DQ
DM
tDQSS (MAX)
WL + tDQSS
1
DQS#
DQS
DI
b
DQ
DM
Transitioning Data
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Don’t Care
1. Subsequent rising DQS signals must align to the clock within tDQSS.
2. DI b = data-in for column b.
3. Three subsequent elements of data-in are applied in the programmed order following
DI b.
4. BL = 4, CL = 3, AL = 0; thus, WL = 2.
5. tWR is referenced from the first positive CK edge after the last data-in pair.
6. The PRECHARGE and WRITE commands are to the same bank. However, the PRECHARGE
and WRITE commands may be to different banks, in which case tWR is not required and
the PRECHARGE command could be applied earlier.
7. A10 is LOW with the WRITE command (auto precharge is disabled).
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WRITE
Figure 62: Bank Write – Without Auto Precharge
CK#
T0
T1
CK
T3
T4
T5
WRITE2
NOP1
NOP1
T2
tCK
tCH
T5n
T6
T6n
T7
T8
T9
NOP1
NOP1
PRE
tCL
CKE
Command
NOP1
ACT
NOP1
Address
RA
Col n
A10
RA
3
NOP1
All banks
One bank
Bank select
Bank x
Bank x4
Bank x
tRCD
tWR
WL = 2
tRP
tRAS
WL ±tDQSS (NOM)
5
DQS, DQS#
tWPRE
tDQSL tDQSH tWPST
DI
n
DQ6
DM
Transitioning Data
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Don’t Care
1. NOP commands are shown for ease of illustration; other commands may be valid at
these times.
2. BL = 4 and AL = 0 in the case shown.
3. Disable auto precharge.
4. “Don’t Care” if A10 is HIGH at T9.
5. Subsequent rising DQS signals must align to the clock within tDQSS.
6. DI n = data-in for column n; subsequent elements are applied in the programmed order.
7. tDSH is applicable during tDQSS (MIN) and is referenced from CK T5 or T6.
8. tDSS is applicable during tDQSS (MAX) and is referenced from CK T6 or T7.
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WRITE
Figure 63: Bank Write – with Auto Precharge
CK#
T0
T1
CK
T2
tCK
tCH
T3
T4
T5
WRITE2
NOP1
NOP1
T5n
T6
T6n
T7
T8
T9
NOP1
NOP1
NOP1
tCL
CKE
Command
NOP1
ACT
Address
RA
A10
RA
NOP1
NOP1
Col n
3
Bank select
Bank x
Bank x
tRCD
WR4
WL = 2
tRP
tRAS
WL ±tDQSS (NOM)
5
DQS, DQS#
tWPRE
tDQSL tDQSH tWPST
DI
n
DQ6
DM
Transitioning Data
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Don’t Care
1. NOP commands are shown for ease of illustration; other commands may be valid at
these times.
2. BL = 4 and AL = 0 in the case shown.
3. Enable auto precharge.
4. WR is programmed via MR9–MR11 and is calculated by dividing tWR (in ns) by tCK and
rounding up to the next integer value.
5. Subsequent rising DQS signals must align to the clock within tDQSS.
6. DI n = data-in from column n; subsequent elements are applied in the programmed order.
7. tDSH is applicable during tDQSS (MIN) and is referenced from CK T5 or T6.
8. tDSS is applicable during tDQSS (MAX) and is referenced from CK T6 or T7.
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WRITE
Figure 64: WRITE – DM Operation
CK#
CK
T0
T1
T2
tCK
T3
tCH
T4
T5
T6
T6n
NOP1
NOP1
WL = 2
NOP1
T7
T7n
T8
T9
T10
T11
tCL
CKE
Command
NOP1
ACT
NOP1
WRITE2
AL = 1
Address
RA
Col n
A10
RA
3
Bank select
NOP1
NOP1
NOP1
NOP1
PRE
All banks
Bank x
One bank
Bank x4
Bank x
tRCD
tWR5
tRPA
tRAS
WL ±tDQSS (NOM)
6
DQS, DQS#
tWPRE
DQ7
tDQSL tDQSH tWPST
DI
n
DM
Transitioning Data
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Don’t Care
1. NOP commands are shown for ease of illustration; other commands may be valid at
these times.
2. BL = 4, AL = 1, and WL = 2 in the case shown.
3. Disable auto precharge.
4. “Don’t Care” if A10 is HIGH at T11.
5. tWR starts at the end of the data burst regardless of the data mask condition.
6. Subsequent rising DQS signals must align to the clock within tDQSS.
7. DI n = data-in for column n; subsequent elements are applied in the programmed order.
8. tDSH is applicable during tDQSS (MIN) and is referenced from CK T6 or T7.
9. tDSS is applicable during tDQSS (MAX) and is referenced from CK T7 or T8.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
PRECHARGE
Figure 65: Data Input Timing
T0
T1
T1n
T2
T2n
T3
T3n
T4
CK#
CK
t DSH 1 t DSS 2
3
WL - tDQSS (NOM)
DQS
DQS#
t WPRE
DQ
t DQSL
t DSH 1 t DSS 2
t DQSH
t WPST
DI
DM
Transitioning Data
Notes:
1.
2.
3.
4.
5.
6.
Don’t Care
tDSH
(MIN) generally occurs during tDQSS (MIN).
(MIN) generally occurs during tDQSS (MAX).
Subsequent rising DQS signals must align to the clock within tDQSS.
WRITE command issued at T0.
For x16, LDQS controls the lower byte and UDQS controls the upper byte.
WRITE command with WL = 2 (CL = 3, AL = 0) issued at T0.
tDSS
PRECHARGE
Precharge can be initiated by either a manual PRECHARGE command or by an autoprecharge in conjunction with either a READ or WRITE command. Precharge will deactivate the open row in a particular bank or the open row in all banks. The PRECHARGE
operation is shown in the previous READ and WRITE operation sections.
During a manual PRECHARGE command, the A10 input determines whether one or all
banks are to be precharged. In the case where only one bank is to be precharged, bank
address inputs determine the bank to be precharged. When all banks are to be precharged, the bank address inputs are treated as “Don’t Care.”
Once a bank has been precharged, it is in the idle state and must be activated prior to
any READ or WRITE commands being issued to that bank. When a single-bank PRECHARGE command is issued, tRP timing applies. When the PRECHARGE (ALL) command is issued, tRPA timing applies, regardless of the number of banks opened.
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REFRESH
REFRESH
The commercial temperature DDR2 SDRAM requires REFRESH cycles at an average interval of 7.8125µs (MAX) and all rows in all banks must be refreshed at least once every
64ms. The refresh period begins when the REFRESH command is registered and ends
tRFC (MIN) later. The average interval must be reduced to 3.9µs (MAX) when T exC
ceeds +85°C.
Figure 66: Refresh Mode
T0
CK#
T2
T1
CK
tCK
tCH
T3
T4
Ta0
Ta1
Tb0
Tb1
Tb2
NOP1
REF
NOP1
REF2
NOP1
NOP1
ACT
tCL
CKE
Command
NOP1
NOP1
PRE
Address
RA
All banks
A10
RA
One bank
Bank
Bank(s)3
BA
DQS, DQS#4
DQ4
DM4
tRP
tRFC (MIN)
tRFC2
Indicates a break in
time scale
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Don’t Care
1. NOP commands are shown for ease of illustration; other valid commands may be possible at these times. CKE must be active during clock positive transitions.
2. The second REFRESH is not required and is only shown as an example of two back-toback REFRESH commands.
3. “Don’t Care” if A10 is HIGH at this point; A10 must be HIGH if more than one bank is
active (must precharge all active banks).
4. DM, DQ, and DQS signals are all “Don’t Care”/High-Z for operations shown.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
SELF REFRESH
SELF REFRESH
The SELF REFRESH command is initiated when CKE is LOW. The differential clock
should remain stable and meet tCKE specifications at least 1 × tCK after entering self
refresh mode. The procedure for exiting self refresh requires a sequence of commands.
First, the differential clock must be stable and meet tCK specifications at least 1 × tCK
prior to CKE going back to HIGH. Once CKE is HIGH (tCKE [MIN] has been satisfied
with three clock registrations), the DDR2 SDRAM must have NOP or DESELECT commands issued for tXSNR. A simple algorithm for meeting both refresh and DLL requirements is used to apply NOP or DESELECT commands for 200 clock cycles before
applying any other command.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
SELF REFRESH
Figure 67: Self Refresh
CK#
CK1
T0
T1
tCH
T2
Ta0
tCK1
tCL
Ta1
tCK1
Tb0
Ta2
tISXR2
Tc0
tCKE3
Td0
t IH
CKE1
Command
NOP
NOP4
REF
NOP4
Valid5
Valid5
t IH
ODT6
tAOFD/tAOFPD6
Address
Valid
Valid7
DQS#, DQS
DQ
DM
tXSRD2, 7
Enter self refresh
mode (synchronous)
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
tXSNR2, 5, 10
tCKE (MIN)9
tRP8
Exit self refresh
mode (asynchronous)
Indicates a break in
time scale
Don’t Care
1. Clock must be stable and meeting tCK specifications at least 1 × tCK after entering self
refresh mode and at least 1 × tCK prior to exiting self refresh mode.
2. Self refresh exit is asynchronous; however, tXSNR and tXSRD timing starts at the first rising clock edge where CKE HIGH satisfies tISXR.
3. CKE must stay HIGH until tXSRD is met; however, if self refresh is being re-entered, CKE
may go back LOW after tXSNR is satisfied.
4. NOP or DESELECT commands are required prior to exiting self refresh until state Tc0,
which allows any nonREAD command.
5. tXSNR is required before any nonREAD command can be applied.
6. ODT must be disabled and RTT off (tAOFD and tAOFPD have been satisfied) prior to entering self refresh at state T1.
7. tXSRD (200 cycles of CK) is required before a READ command can be applied at state Td0.
8. Device must be in the all banks idle state prior to entering self refresh mode.
9. After self refresh has been entered, tCKE (MIN) must be satisfied prior to exiting self
refresh.
10. Upon exiting SELF REFRESH, ODT must remain LOW until tXSRD is satisfied.
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Power-Down Mode
Power-Down Mode
DDR2 SDRAM supports multiple power-down modes that allow significant power savings over normal operating modes. CKE is used to enter and exit different power-down
modes. Power-down entry and exit timings are shown in Figure 68 (page 112). Detailed
power-down entry conditions are shown in Figure 69 (page 114)–Figure 76 (page 117).
Table 43 (page 113) is the CKE Truth Table.
DDR2 SDRAM requires CKE to be registered HIGH (active) at all times that an access is
in progress—from the issuing of a READ or WRITE command until completion of the
burst. Thus, a clock suspend is not supported. For READs, a burst completion is defined
when the read postamble is satisfied; for WRITEs, a burst completion is defined when
the write postamble and tWR (WRITE-to-PRECHARGE command) or tWTR (WRITE-toREAD command) are satisfied, as shown in Figure 71 (page 115) and Figure 72
(page 115) on Figure 72 (page 115). The number of clock cycles required to meet tWTR
is either two or tWTR/tCK, whichever is greater.
Power-down mode (see Figure 68 (page 112)) is entered when CKE is registered low
coincident with an NOP or DESELECT command. CKE is not allowed to go LOW during
a mode register or extended mode register command time, or while a READ or WRITE
operation is in progress. If power-down occurs when all banks are idle, this mode is
referred to as precharge 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#, ODT, and CKE. For maximum
power savings, the DLL is frozen during precharge power-down. Exiting active powerdown requires the device to be at the same voltage and frequency as when it entered
power-down. Exiting precharge power-down requires the device to be at the same voltage as when it entered power-down; however, the clock frequency is allowed to change
(see Precharge Power-Down Clock Frequency Change (page 118)).
The maximum duration for either active or precharge power-down is limited by the refresh requirements of the device tRFC (MAX). The minimum duration for power-down
entry and exit is limited by the tCKE (MIN) parameter. The following must be maintained while in power-down mode: CKE LOW, a stable clock signal, and stable power
supply signals at the inputs of the DDR2 SDRAM. All other input signals are “Don’t
Care” except ODT. Detailed ODT timing diagrams for different power-down modes are
shown in Figure 81 (page 123)–Figure 86 (page 127).
The power-down state is synchronously exited when CKE is registered HIGH (in conjunction with a NOP or DESELECT command), as shown in Figure 68 (page 112).
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Power-Down Mode
Figure 68: Power-Down
T1
T2
T3
T4
T5
T6
T7
T8
NOP
NOP
Valid
Valid
CK#
CK
Command
tCH
tCK
Valid1
tCL
NOP
tCKE (MIN)2
tIH
CKE
tCKE (MIN)2
tIH
tIS
Address
Valid
Valid
Valid
tXP3, tXARD4
tXARDS5
DQS, DQS#
DQ
DM
Enter
power-down
mode6
Notes:
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2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Exit
power-down
mode
Don’t Care
1. If this command is a PRECHARGE (or if the device is already in the idle state), then the
power-down mode shown is precharge power-down. If this command is an ACTIVATE
(or if at least one row is already active), then the power-down mode shown is active powerdown.
2. tCKE (MIN) of three clocks means CKE must be registered on three consecutive positive
clock edges. CKE must remain at the valid input level the entire time it takes to achieve
the three clocks of registration. Thus, after any CKE transition, CKE may not transition
from its valid level during the time period of tIS + 2 × tCK + tIH. CKE must not transition
during its tIS and tIH window.
3. tXP timing is used for exit precharge power-down and active power-down to any nonREAD command.
4. tXARD timing is used for exit active power-down to READ command if fast exit is selected via MR (bit 12 = 0).
5. tXARDS timing is used for exit active power-down to READ command if slow exit is selected via MR (bit 12 = 1).
6. No column accesses are allowed to be in progress at the time power-down is entered. If
the DLL was not in a locked state when CKE went LOW, the DLL must be reset after
exiting power-down mode for proper READ operation.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Power-Down Mode
Table 43: Truth Table – CKE
Notes 1–4 apply to the entire table
CKE
Current State
Previous Cycle
(n - 1)
Current
Cycle (n)
Command (n)
CS#, RAS#, CAS#,
WE#
Action (n)
Notes
Power-down
L
L
X
Maintain power-down
5, 6
L
H
DESELECT or NOP
Power-down exit
7, 8
L
L
X
Maintain self refresh
6
L
H
DESELECT or NOP
Self refresh exit
7, 9, 10
Bank(s) active
H
L
DESELECT or NOP Active power-down entry
All banks idle
H
L
DESELECT or NOP
Precharge power-down
entry
7, 8, 11
H
L
Refresh
Self refresh entry
10, 12, 13
H
H
Self refresh
Notes:
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Shown in Table 36 (page 64)
7, 8, 11, 12
14
1. CKE (n) is the logic state of CKE at clock edge n; CKE (n - 1) was the state of CKE at the
previous clock edge.
2. Current state is the state of the DDR2 SDRAM immediately prior to clock edge n.
3. Command (n) is the command registered at clock edge n, and action (n) is a result of
command (n).
4. The state of ODT does not affect the states described in this table. The ODT function is
not available during self refresh (see ODT Timing (page 121) for more details and specific restrictions).
5. Power-down modes do not perform any REFRESH operations. The duration of powerdown mode is therefore limited by the refresh requirements.
6. “X” means “Don’t Care” (including floating around VREF) in self refresh and powerdown. However, ODT must be driven high or low in power-down if the ODT function is
enabled via EMR.
7. All states and sequences not shown are illegal or reserved unless explicitly described elsewhere in this document.
8. Valid commands for power-down entry and exit are NOP and DESELECT only.
9. On self refresh exit, DESELECT or NOP commands must be issued on every clock edge
occurring during the tXSNR period. READ commands may be issued only after tXSRD
(200 clocks) is satisfied.
10. Valid commands for self refresh exit are NOP and DESELECT only.
11. Power-down and self refresh can not be entered while READ or WRITE operations,
LOAD MODE operations, or PRECHARGE operations are in progress. See SELF REFRESH
(page 109) and SELF REFRESH (page 70) for a list of detailed restrictions.
12. Minimum CKE high time is tCKE = 3 × tCK. Minimum CKE LOW time is tCKE = 3 × tCK.
This requires a minimum of 3 clock cycles of registration.
13. Self refresh mode can only be entered from the all banks idle state.
14. Must be a legal command, as defined in Table 36 (page 64).
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Power-Down Mode
Figure 69: READ-to-Power-Down or Self Refresh Entry
CK#
T0
T1
T2
T3
T4
T5
READ
NOP
NOP
NOP
Valid
Valid
T6
T7
CK
Command
NOP1
tCKE (MIN)
CKE
Address
Valid
A10
DQS, DQS#
DQ
DO
DO
RL = 3
DO
DO
Power-down2 or
self refresh entry
Transitioning Data
Notes:
Don’t Care
1. In the example shown, READ burst completes at T5; earliest power-down or self refresh
entry is at T6.
2. Power-down or self refresh entry may occur after the READ burst completes.
Figure 70: READ with Auto Precharge-to-Power-Down or Self Refresh Entry
CK#
T0
T1
T2
T3
T4
T5
T6
READ
NOP
NOP
NOP
Valid
Valid
NOP1
T7
CK
Command
tCKE (MIN)
CKE
Address
Valid
A10
DQS, DQS#
DQ
RL = 3
DO
DO
DO
DO
Power-down or
self refresh2 entry
Transitioning Data
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Don’t Care
1. In the example shown, READ burst completes at T5; earliest power-down or self refresh
entry is at T6.
2. Power-down or self refresh entry may occur after the READ burst completes.
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Power-Down Mode
Figure 71: WRITE-to-Power-Down or Self Refresh Entry
CK#
CK
Command
T0
T1
T2
T3
T4
T5
T6
T7
WRITE
NOP
NOP
NOP
Valid
Valid
Valid
NOP1
T8
tCKE (MIN)
CKE
Address
Valid
A10
DQS, DQS#
DQ
DO
DO
DO
DO
tWTR
WL = 3
Power-down or
self refresh entry1
Transitioning Data
Note:
Don’t Care
1. Power-down or self refresh entry may occur after the WRITE burst completes.
Figure 72: WRITE with Auto Precharge-to-Power-Down or Self Refresh Entry
CK#
CK
Command
T0
T1
T2
T3
T4
T5
Ta0
Ta1
WRITE
NOP
NOP
NOP
Valid
Valid
Valid1
NOP
Ta2
tCKE (MIN)
CKE
Address
Valid
A10
DQS, DQS#
DQ
DO
DO
DO
DO
WR2
WL = 3
Power-down or
self refresh entry
Indicates a break in
time scale
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Transitioning Data
Don’t Care
1. Internal PRECHARGE occurs at Ta0 when WR has completed; power-down entry may occur 1 x tCK later at Ta1, prior to tRP being satisfied.
2. WR is programmed through MR9–MR11 and represents (tWR [MIN] ns/tCK) rounded up
to next integer tCK.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
Power-Down Mode
Figure 73: REFRESH Command-to-Power-Down Entry
CK#
T0
T1
T2
Valid
REFRESH
NOP
T3
CK
Command
tCKE (MIN)
CKE
1 x tCK
Power-down1
entry
Don’t Care
Note:
1. The earliest precharge power-down entry may occur is at T2, which is 1 × tCK after the
REFRESH command. Precharge power-down entry occurs prior to tRFC (MIN) being satisfied.
Figure 74: ACTIVATE Command-to-Power-Down Entry
CK#
T0
T1
T2
Valid
ACT
NOP
T3
CK
Command
Address
VALID
tCKE (MIN)
CKE
1 tCK
Power-down1
entry
Don’t Care
Note:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
1. The earliest active power-down entry may occur is at T2, which is 1 × tCK after the ACTIVATE command. Active power-down entry occurs prior to tRCD (MIN) being satisfied.
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Power-Down Mode
Figure 75: PRECHARGE Command-to-Power-Down Entry
T0
T1
T2
Valid
PRE
NOP
CK#
T3
CK
Command
Address
Valid
All banks
vs
Single bank
A10
tCKE
(MIN)
CKE
1 x tCK
Power-down1
entry
Don’t Care
Note:
1. The earliest precharge power-down entry may occur is at T2, which is 1 × tCK after the
PRECHARGE command. Precharge power-down entry occurs prior to tRP (MIN) being satisfied.
Figure 76: LOAD MODE Command-to-Power-Down Entry
CK#
T0
T1
T2
T3
Valid
LM
NOP
NOP
T4
CK
Command
Valid1
Address
tCKE (MIN)
CKE
tRP2
tMRD
Power-down3
entry
Don’t Care
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
1. Valid address for LM command includes MR, EMR, EMR(2), and EMR(3) registers.
2. All banks must be in the precharged state and tRP met prior to issuing LM command.
3. The earliest precharge power-down entry is at T3, which is after tMRD is satisfied.
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Precharge Power-Down Clock Frequency Change
Precharge Power-Down Clock Frequency Change
When the DDR2 SDRAM is in precharge power-down mode, ODT must be turned off
and CKE must be at a logic LOW level. A minimum of two differential clock cycles must
pass after CKE goes LOW before clock frequency may change. The device input clock
frequency is allowed to change only within minimum and maximum operating frequencies specified for the particular speed grade. During input clock frequency change, ODT
and CKE must be held at stable LOW levels. When the input clock frequency is changed,
new stable clocks must be provided to the device before precharge power-down may be
exited, and DLL must be reset via MR after precharge power-down exit. Depending on
the new clock frequency, additional LM commands might be required to adjust the CL,
WR, AL, and so forth. Depending on the new clock frequency, an additional LM command might be required to appropriately set the WR MR9, MR10, MR11. During the
DLL relock period of 200 cycles, ODT must remain off. After the DLL lock time, the
DRAM is ready to operate with a new clock frequency.
Figure 77: Input Clock Frequency Change During Precharge Power-Down Mode
New clock frequency
Previous clock frequency
CK#
CK
T0
T1
tCH
T2
T3
Ta1
Ta0
tCH
tCL
Ta2
Ta3
Ta4
Tb0
NOP
Valid
tCL
tCK
tCK
2 x tCK (MIN)1
1 x tCK (MIN)2
tCKE (MIN)3
tCKE (MIN)3
CKE
Command
Address
Valid4
NOP
NOP
NOP
Valid
LM
DLL RESET
Valid
tXP
ODT
DQS, DQS#
DQ
High-Z
High-Z
DM
Enter precharge
power-down mode
Frequency
change
Exit precharge
power-down mode
200 x tCK
Indicates a break in
time scale
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Don’t Care
1. A minimum of 2 × tCK is required after entering precharge power-down prior to changing clock frequencies.
2. When the new clock frequency has changed and is stable, a minimum of 1 × tCK is required prior to exiting precharge power-down.
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Reset
3. Minimum CKE high time is tCKE = 3 × tCK. Minimum CKE LOW time is tCKE = 3 × tCK.
This requires a minimum of three clock cycles of registration.
4. If this command is a PRECHARGE (or if the device is already in the idle state), then the
power-down mode shown is precharge power-down, which is required prior to the
clock frequency change.
Reset
CKE Low Anytime
DDR2 SDRAM applications may go into a reset state anytime during normal operation.
If an application enters a reset condition, CKE is used to ensure the DDR2 SDRAM device resumes normal operation after reinitializing. All data will be lost during a reset
condition; however, the DDR2 SDRAM device will continue to operate properly if the
following conditions outlined in this section are satisfied.
The reset condition defined here assumes all supply voltages (VDD, VDDQ, VDDL, and
VREF) are stable and meet all DC specifications prior to, during, and after the RESET operation. All other input balls of the DDR2 SDRAM device are a “Don’t Care” during
RESET with the exception of CKE.
If CKE asynchronously drops LOW during any valid operation (including a READ or
WRITE burst), the memory controller must satisfy the timing parameter tDELAY before
turning off the clocks. Stable clocks must exist at the CK, CK# inputs of the DRAM before CKE is raised HIGH, at which time the normal initialization sequence must occur
(see Initialization). The DDR2 SDRAM device is now ready for normal operation after
the initialization sequence. Figure 78 (page 120) shows the proper sequence for a RESET operation.
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Reset
Figure 78: RESET Function
T0
T1
T2
T3
T4
T5
tCK
CK#
CK
tDELAY
tCL
Tb0
Ta0
tCL
tCKE (MIN)
1
CKE
ODT
Command
NOP2
READ
READ
NOP2
NOP2
NOP2
PRE
DM3
Address
Col n
Col n
All banks
A10
Bank address
Bank a
DQS3
DQ3
Bank b
High-Z
High-Z
High-Z
DO
DO
4
High-Z
DO
High-Z
RTT
System
RESET
T = 400ns (MIN)
tRPA
Start of normal5
initialization
sequence
Indicates a break in
time scale
Notes:
PDF: 09005aef844ec98c
2gbddr2_1.55V.pdf – Rev. A 1/11 EN
Unknown
RTT On
Transitioning Data
Don’t Care
1. VDD, VDDL, VDDQ, VTT, and VREF must be valid at all times.
2. Either NOP or DESELECT command may be applied.
3. DM represents DM for x4/x8 configuration and UDM, LDM for x16 configuration. DQS
represents DQS, DQS#, UDQS, UDQS#, LDQS, LDQS#, RDQS, and RDQS# for the appropriate configuration (x4, x8, x16).
4. In certain cases where a READ cycle is interrupted, CKE going HIGH may result in the
completion of the burst.
5. Initialization timing is shown in Figure 41 (page 81).
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
ODT Timing
ODT Timing
Once a 12ns delay (tMOD) has been satisfied, and after the ODT function has been enabled via the EMR LOAD MODE command, ODT can be accessed under two timing
categories. ODT will operate either in synchronous mode or asynchronous mode, depending on the state of CKE. ODT can switch anytime except during self refresh mode
and a few clocks after being enabled via EMR, as shown in Figure 79 (page 122).
There are two timing categories for ODT—turn-on and turn-off. During active mode
(CKE HIGH) and fast-exit power-down mode (any row of any bank open, CKE LOW,
MR[12 = 0]), tAOND, tAON, tAOFD, and tAOF timing parameters are applied, as shown
in Figure 81 (page 123).
During slow-exit power-down mode (any row of any bank open, CKE LOW, MR[12] = 1)
and precharge power-down mode (all banks/rows precharged and idle, CKE LOW),
tAONPD and tAOFPD timing parameters are applied, as shown in Figure 82 (page 124).
ODT turn-off timing, prior to entering any power-down mode, is determined by the parameter tANPD (MIN), as shown in Figure 83 (page 124). At state T2, the ODT HIGH
signal satisfies tANPD (MIN) prior to entering power-down mode at T5. When tANPD
(MIN) is satisfied, tAOFD and tAOF timing parameters apply. Figure 83 (page 124) also
shows the example where tANPD (MIN) is not satisfied because ODT HIGH does not
occur until state T3. When tANPD (MIN) is not satisfied, tAOFPD timing parameters apply.
ODT turn-on timing prior to entering any power-down mode is determined by the parameter tANPD, as shown in Figure 84 (page 125). At state T2, the ODT HIGH signal
satisfies tANPD (MIN) prior to entering power-down mode at T5. When tANPD (MIN) is
satisfied, tAOND and tAON timing parameters apply. Figure 84 (page 125) also shows
the example where tANPD (MIN) is not satisfied because ODT HIGH does not occur
until state T3. When tANPD (MIN) is not satisfied, tAONPD timing parameters apply.
ODT turn-off timing after exiting any power-down mode is determined by the parameter tAXPD (MIN), as shown in Figure 85 (page 126). At state Ta1, the ODT LOW signal
satisfies tAXPD (MIN) after exiting power-down mode at state T1. When tAXPD (MIN) is
satisfied, tAOFD and tAOF timing parameters apply. Figure 85 (page 126) also shows
the example where tAXPD (MIN) is not satisfied because ODT LOW occurs at state Ta0.
When tAXPD (MIN) is not satisfied, tAOFPD timing parameters apply.
ODT turn-on timing after exiting either slow-exit power-down mode or precharge powerdown mode is determined by the parameter tAXPD (MIN), as shown in Figure 86
(page 127). At state Ta1, the ODT HIGH signal satisfies tAXPD (MIN) after exiting powerdown mode at state T1. When tAXPD (MIN) is satisfied, tAOND and tAON timing
parameters apply. Figure 86 (page 127) also shows the example where tAXPD (MIN) is
not satisfied because ODT HIGH occurs at state Ta0. When tAXPD (MIN) is not satisfied,
tAONPD timing parameters apply.
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
ODT Timing
Figure 79: ODT Timing for Entering and Exiting Power-Down Mode
Synchronous
Synchronous or
Synchronous
Asynchronous
tANPD (3 tCKs)
First CKE latched LOW
tAXPD (8 tCKs)
First CKE latched HIGH
CKE
Any mode except
self refresh mode
Applicable modes
tAOND/tAOFD
Active power-down fast (synchronous)
Any mode except
self refresh mode
Active power-down slow (asynchronous)
Precharge power-down (asynchronous)
tAOND/tAOFD
(synchronous)
tAONPD/tAOFPD
tAOND/tAOFD
(asynchronous)
Applicable timing parameters
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
ODT Timing
MRS Command to ODT Update Delay
During normal operation, the value of the effective termination resistance can be
changed with an EMRS set command. tMOD (MAX) updates the RTT setting.
Figure 80: Timing for MRS Command to ODT Update Delay
T0
Command
Ta0
Ta1
Ta2
Ta3
Ta4
Ta5
EMRS1
NOP
NOP
NOP
NOP
NOP
CK#
CK
2
ODT2
tMOD
tAOFD
tIS
0ns
Internal
RTT setting
Old setting
Undefined
New setting
Indicates a break in
time scale
Notes:
1. The LM command is directed to the mode register, which updates the information in
EMR (A6, A2), that is, RTT (nominal).
2. To prevent any impedance glitch on the channel, the following conditions must be met:
tAOFD must be met before issuing the LM command; ODT must remain LOW for the
entire duration of the tMOD window until tMOD is met.
Figure 81: ODT Timing for Active or Fast-Exit Power-Down Mode
CK#
T0
CK
T1
tCK
tCH
T2
T3
T4
T5
T6
tCL
Command
Valid
Valid
Valid
Valid
Valid
Valid
Valid
Address
Valid
Valid
Valid
Valid
Valid
Valid
Valid
CKE
tAOND
ODT
tAOFD
RTT
tAON (MIN)
tAOF (MAX)
tAON (MAX)
tAOF (MIN)
RTT Unknown
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123
RTT On
Don’t Care
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
ODT Timing
Figure 82: ODT Timing for Slow-Exit or Precharge Power-Down Modes
CK#
T0
CK
T1
tCK
tCH
T2
T3
T4
T5
T6
T7
tCL
Command
Valid
Valid
Valid
Valid
Valid
Valid
Valid
Valid
Address
Valid
Valid
Valid
Valid
Valid
Valid
Valid
Valid
CKE
ODT
tAONPD (MAX)
tAONPD (MIN)
RTT
tAOFPD (MIN)
tAOFPD (MAX)
Transitioning RTT
RTT Unknown
RTT On
Don’t Care
Figure 83: ODT Turn-Off Timings When Entering Power-Down Mode
CK#
T0
T1
T2
T3
T4
T5
T6
NOP
NOP
NOP
NOP
NOP
NOP
NOP
CK
Command
tANPD (MIN)
CKE
tAOFD
ODT
tAOF (MAX)
RTT
tAOF (MIN)
tAOFPD (MAX)
ODT
RTT
tAOFPD (MIN)
Transitioning RTT
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RTT Unknown
RTT ON
Don’t Care
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
ODT Timing
Figure 84: ODT Turn-On Timing When Entering Power-Down Mode
CK#
T0
T1
T2
T3
T4
T5
T6
NOP
NOP
NOP
NOP
NOP
NOP
NOP
CK
Command
tANPD (MIN)
CKE
ODT
tAOND
tAON (MAX)
RTT
tAON (MIN)
ODT
tAONPD (MAX)
RTT
tAONPD (MIN)
Transitioning RTT
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125
RTT Unknown
RTT On
Don’t Care
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
ODT Timing
Figure 85: ODT Turn-Off Timing When Exiting Power-Down Mode
CK#
T0
T1
T2
T3
T4
Ta0
Ta1
Ta2
Ta3
Ta4
Ta5
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
CK
Command
tAXPD (MIN)
CKE
tCKE (MIN)
tAOFD
ODT
tAOF (MAX)
RTT
tAOF (MIN)
tAOFPD (MAX)
ODT
RTT
tAOFPD (MIN)
Indicates a break in
time scale
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RTT Unknown
126
RTT On
Transitioning RTT
Don’t Care
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2Gb: x4, x8, x16 1.55V DDR2 SDRAM
ODT Timing
Figure 86: ODT Turn-On Timing When Exiting Power-Down Mode
CK#
T0
T1
T2
T3
T4
Ta0
Ta1
Ta2
Ta3
Ta4
Ta5
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
CK
Command
tAXPD (MIN)
CKE
tCKE (MIN)
ODT
tAOND
tAON (MAX)
RTT
tAON (MIN)
ODT
tAONPD (MAX)
RTT
tAONPD (MIN)
Indicates a break in
time scale
RTT Unknown
RTT On
Transitioning RTT
Don’t Care
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www.micron.com/productsupport Customer Comment Line: 800-932-4992
Micron and the Micron logo are trademarks of Micron Technology, Inc.
All other trademarks are the property of their respective owners.
This data sheet contains minimum and maximum limits specified over the power supply and temperature range set forth herein.
Although considered final, these specifications are subject to change, as further product development and data characterization sometimes occur.
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