MICRON MT47H16M16BG-3ITB

256Mb: x4, x8, x16 DDR2 SDRAM
Features
DDR2 SDRAM
MT47H64M4 – 16 Meg x 4 x 4 banks
MT47H32M8 – 8 Meg x 8 x 4 banks
MT47H16M16 – 4 Meg x 16 x 4 banks
Options1
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Marking
• Configuration
– 64 Meg x 4 (16 Meg x 4 x 4 banks)
– 32 Meg x 8 (8 Meg x 8 x 4 banks)
– 16 Meg x 16 (4 Meg x 16 x 4 banks)
• FBGA package (Pb-free)
– 60-ball FBGA (8mm x 12mm) x4, x8
– 84-ball FBGA (8mm x 14mm) x16
• FBGA package (lead solder)
– 60-ball FBGA (8mm x 12mm) x4, x8
– 84-ball FBGA (8mm x 14mm) x16
• Timing – cycle time
– 3.0ns @ CL = 5 (DDR2-667)
– 3.75ns @ CL = 4 (DDR2-533)
– 5.0ns @ CL = 3 (DDR2-400)
• Self refresh
– Standard
– Low-power
• Operating temperature
– Commercial (0°C ื T C ื +85°C)
– Industrial (–40°C ื T C ื +95°C;
–40°C ื T A ื +85°C)
– Automotive (–40°C ื T C, T A ื +105°C)
• Revision
VDD = 1.8V ±0.1V, V DDQ = 1.8V ±0.1V
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
4 internal banks for concurrent operation
Programmable CAS latency (CL)
Posted CAS additive latency (AL)
WRITE latency = READ latency - 1 tCK
Selectable burst lengths (BL): 4 or 8
Adjustable data-output drive strength
64ms, 8192-cycle refresh
On-die termination (ODT)
Industrial temperature (IT) option
Automotive temperature (AT) option
RoHS-compliant
Supports JEDEC clock jitter specification
Note:
64M4
32M8
16M16
BP
BG
FP
FG
-3
-37E
-5E
None
L
None
IT
AT
:B
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 (MT/s)
tRC
Speed Grade
CL = 3
CL = 4
CL = 5
-3
400
533
667
55
-37E
400
533
n/a
55
-5E
400
400
n/a
55
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1
(ns)
Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
Products and specifications discussed herein are subject to change by Micron without notice.
256Mb: x4, x8, x16 DDR2 SDRAM
Features
Table 2: Addressing
Parameter
Configuration
64 Meg x 4
32 Meg x 8
16 Meg x 16
16 Meg x 4 x 4 banks
8 Meg x 8 x 4 banks
4 Meg x 16 x 4 banks
Refresh count
8K
8K
8K
Row address
A[12:0] (8K)
A[12:0] (8K)
A[12:0] (8K)
Bank address
BA[1:0] (4)
BA[1:0] (4)
BA[1:0] (4)
A[11, 9:0] (2K)
A[9:0] (1K)
A[8:0] (512)
Column address
Figure 1: 256Mb DDR2 Part Numbers
Example Part Number: MT47H32M8BP-3 :B
MT47H
Package
Speed
Revision
^
Configuration
:
:B Revision
Configuration
64 Meg x 4
64M4
L Low power
32 Meg x 8
32M8
IT Industrial temperature
16 Meg x 16
16M16
AT Automotive temperature
Package
Pb-free
84-ball 8mm x 14mm FBGA
BG
60-ball 8mm x 12mm FBGA
BP
Lead solder
84-ball 8mm x 14mm FBGA
FG
60-ball 8mm x 12mm FBGA
FP
Note:
-3
Speed Grade
tCK = 3ns, CL = 5
-37E tCK = 3.75ns, CL = 4
-5E tCK = 5ns, CL = 3
1. Not all speeds and configurations are available in all packages.
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.
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Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
256Mb: x4, x8, x16 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 ................................................................................................................ 27
AC and DC Operating Conditions .................................................................................................................... 39
ODT DC Electrical Characteristics ................................................................................................................... 40
Input Electrical Characteristics and Operating Conditions ............................................................................... 41
Output Electrical Characteristics and Operating Conditions ............................................................................. 44
Output Driver Characteristics ......................................................................................................................... 46
Power and Ground Clamp Characteristics ....................................................................................................... 50
AC Overshoot/Undershoot Specification ......................................................................................................... 51
Input Slew Rate Derating ................................................................................................................................ 53
Commands .................................................................................................................................................... 66
Truth Tables ............................................................................................................................................... 66
DESELECT ................................................................................................................................................. 70
NO OPERATION (NOP) ............................................................................................................................... 71
LOAD MODE (LM) ...................................................................................................................................... 71
ACTIVATE .................................................................................................................................................. 71
READ ......................................................................................................................................................... 71
WRITE ....................................................................................................................................................... 71
PRECHARGE .............................................................................................................................................. 72
REFRESH ................................................................................................................................................... 72
SELF REFRESH ........................................................................................................................................... 72
Mode Register (MR) ........................................................................................................................................ 72
Burst Length .............................................................................................................................................. 73
Burst Type .................................................................................................................................................. 74
Operating Mode ......................................................................................................................................... 74
DLL RESET ................................................................................................................................................. 74
Write Recovery ........................................................................................................................................... 75
Power-Down Mode ..................................................................................................................................... 75
CAS Latency (CL) ........................................................................................................................................ 76
Extended Mode Register (EMR) ....................................................................................................................... 77
DLL Enable/Disable ................................................................................................................................... 78
Output Drive Strength ................................................................................................................................ 78
DQS# Enable/Disable ................................................................................................................................. 78
RDQS Enable/Disable ................................................................................................................................. 78
Output Enable/Disable ............................................................................................................................... 78
On-Die Termination (ODT) ......................................................................................................................... 79
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256Mb: x4, x8, x16 DDR2 SDRAM
Features
Off-Chip Driver (OCD) Impedance Calibration ............................................................................................ 79
Posted CAS Additive Latency (AL) ................................................................................................................ 79
Extended Mode Register 2 (EMR2) ................................................................................................................... 81
Extended Mode Register 3 (EMR3) ................................................................................................................... 82
Initialization .................................................................................................................................................. 83
ACTIVATE ...................................................................................................................................................... 86
READ ............................................................................................................................................................. 88
READ with Precharge .................................................................................................................................. 92
READ with Auto Precharge .......................................................................................................................... 94
WRITE ........................................................................................................................................................... 99
PRECHARGE ................................................................................................................................................. 109
REFRESH ...................................................................................................................................................... 110
SELF REFRESH .............................................................................................................................................. 111
Power-Down Mode ........................................................................................................................................ 113
Precharge Power-Down Clock Frequency Change ........................................................................................... 120
Reset ............................................................................................................................................................. 121
CKE Low Anytime ...................................................................................................................................... 121
ODT Timing .................................................................................................................................................. 123
MRS Command to ODT Update Delay ........................................................................................................ 125
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256MbDDR2.pdf - Rev. N 7/11 EN
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Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
256Mb: x4, x8, x16 DDR2 SDRAM
Features
List of Figures
Figure 1: 256Mb DDR2 Part Numbers ............................................................................................................... 2
Figure 2: Simplified State Diagram ................................................................................................................... 8
Figure 3: 64 Meg x 4 Functional Block Diagram ............................................................................................... 11
Figure 4: 32 Meg x 8 Functional Block Diagram ............................................................................................... 12
Figure 5: 16 Meg x 16 Functional Block Diagram ............................................................................................. 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 (8mm x 14mm) – x16 ..................................................................................... 18
Figure 9: 60-Ball, FBGA Package (8mm x 12mm) – x4, x8 ................................................................................. 19
Figure 10: Example Temperature Test Point Location ...................................................................................... 22
Figure 11: Single-Ended Input Signal Levels ................................................................................................... 41
Figure 12: Differential Input Signal Levels ...................................................................................................... 42
Figure 13: Differential Output Signal Levels .................................................................................................... 44
Figure 14: Output Slew Rate Load .................................................................................................................. 45
Figure 15: Full Strength Pull-Down Characteristics ......................................................................................... 46
Figure 16: Full Strength Pull-Up Characteristics .............................................................................................. 47
Figure 17: Reduced Strength Pull-Down Characteristics .................................................................................. 48
Figure 18: Reduced Strength Pull-Up Characteristics ...................................................................................... 49
Figure 19: Input Clamp Characteristics .......................................................................................................... 50
Figure 20: Overshoot ..................................................................................................................................... 51
Figure 21: Undershoot ................................................................................................................................... 51
Figure 22: Nominal Slew Rate for tIS ............................................................................................................... 56
Figure 23: Tangent Line for tIS ........................................................................................................................ 56
Figure 24: Nominal Slew Rate for tIH .............................................................................................................. 57
Figure 25: Tangent Line for tIH ....................................................................................................................... 57
Figure 26: Nominal Slew Rate for tDS ............................................................................................................. 62
Figure 27: Tangent Line for tDS ...................................................................................................................... 62
Figure 28: Nominal Slew Rate for tDH ............................................................................................................. 63
Figure 29: Tangent Line for tDH ..................................................................................................................... 63
Figure 30: AC Input Test Signal Waveform Command/Address Balls ................................................................ 64
Figure 31: AC Input Test Signal Waveform for Data with DQS, DQS# (Differential) ............................................ 64
Figure 32: AC Input Test Signal Waveform for Data with DQS (Single-Ended) ................................................... 65
Figure 33: AC Input Test Signal Waveform (Differential) .................................................................................. 65
Figure 34: MR Definition ............................................................................................................................... 73
Figure 35: CL ................................................................................................................................................. 76
Figure 36: EMR Definition ............................................................................................................................. 77
Figure 37: READ Latency ............................................................................................................................... 80
Figure 38: WRITE Latency .............................................................................................................................. 80
Figure 39: EMR2 Definition ........................................................................................................................... 81
Figure 40: EMR3 Definition ........................................................................................................................... 82
Figure 41: DDR2 Power-Up and Initialization ................................................................................................. 83
Figure 42: Example: Meeting tRRD (MIN) and tRCD (MIN) .............................................................................. 86
Figure 43: Multibank Activate Restriction ....................................................................................................... 87
Figure 44: READ Latency ............................................................................................................................... 89
Figure 45: Consecutive READ Bursts .............................................................................................................. 90
Figure 46: Nonconsecutive READ Bursts ........................................................................................................ 91
Figure 47: READ Interrupted by READ ............................................................................................................ 92
Figure 48: READ-to-WRITE ............................................................................................................................ 92
Figure 49: READ-to-PRECHARGE – BL = 4 ...................................................................................................... 93
Figure 50: READ-to-PRECHARGE – BL = 8 ...................................................................................................... 93
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‹ 2003 Micron Technology, Inc. All rights reserved.
256Mb: x4, x8, x16 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 .............................................................................................. 95
Bank Read – with Auto Precharge ................................................................................................... 96
x4, x8 Data Output Timing – tDQSQ, tQH, and Data Valid Window ................................................... 97
x16 Data Output Timing – tDQSQ, tQH, and Data Valid Window ...................................................... 98
Data Output Timing – tAC and tDQSCK .......................................................................................... 99
Write Burst ................................................................................................................................... 101
Consecutive WRITE-to-WRITE ...................................................................................................... 102
Nonconsecutive WRITE-to-WRITE ................................................................................................ 102
WRITE Interrupted by WRITE ....................................................................................................... 103
WRITE-to-READ ........................................................................................................................... 104
WRITE-to-PRECHARGE ................................................................................................................ 105
Bank Write – Without Auto Precharge ............................................................................................ 106
Bank Write – with Auto Precharge .................................................................................................. 107
WRITE – DM Operation ................................................................................................................ 108
Data Input Timing ........................................................................................................................ 109
Refresh Mode ............................................................................................................................... 110
Self Refresh .................................................................................................................................. 112
Power-Down ................................................................................................................................ 114
READ-to-Power-Down or Self Refresh Entry .................................................................................. 116
READ with Auto Precharge-to-Power-Down or Self Refresh Entry ................................................... 116
WRITE-to-Power-Down or Self Refresh Entry ................................................................................. 117
WRITE with Auto Precharge-to-Power-Down or Self Refresh Entry .................................................. 117
REFRESH Command-to-Power-Down Entry .................................................................................. 118
ACTIVATE Command-to-Power-Down Entry ................................................................................. 118
PRECHARGE Command-to-Power-Down Entry ............................................................................. 119
LOAD MODE Command-to-Power-Down Entry ............................................................................. 119
Input Clock Frequency Change During Precharge Power-Down Mode ............................................ 120
RESET Function ........................................................................................................................... 122
ODT Timing for Entering and Exiting Power-Down Mode ............................................................... 124
Timing for MRS Command to ODT Update Delay .......................................................................... 125
ODT Timing for Active or Fast-Exit Power-Down Mode .................................................................. 125
ODT Timing for Slow-Exit or Precharge Power-Down Modes .......................................................... 126
ODT Turn-Off Timings When Entering Power-Down Mode ............................................................ 126
ODT Turn-On Timing When Entering Power-Down Mode .............................................................. 127
ODT Turn-Off Timing When Exiting Power-Down Mode ................................................................ 128
ODT Turn-On Timing When Exiting Power-Down Mode ................................................................. 129
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‹ 2003 Micron Technology, Inc. All rights reserved.
256Mb: x4, x8, x16 DDR2 SDRAM
Features
List of Tables
Table 1: Key Timing Parameters ....................................................................................................................... 1
Table 2: Addressing ......................................................................................................................................... 2
Table 3: FBGA 60-Ball – x4, x8 and 84-Ball – x16 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 (4-Bank Interleave READ Operation) ................................................................. 24
Table 10: DDR2 IDD Specifications and Conditions ......................................................................................... 25
Table 11: AC Operating Specifications and Conditions .................................................................................... 27
Table 12: Recommended DC Operating Conditions (SSTL_18) ........................................................................ 39
Table 13: ODT DC Electrical Characteristics ................................................................................................... 40
Table 14: Input DC Logic Levels ..................................................................................................................... 41
Table 15: Input AC Logic Levels ...................................................................................................................... 41
Table 16: Differential Input Logic Levels ......................................................................................................... 42
Table 17: Differential AC Output Parameters ................................................................................................... 44
Table 18: Output DC Current Drive ................................................................................................................ 44
Table 19: Output Characteristics .................................................................................................................... 45
Table 20: Full Strength Pull-Down Current (mA) ............................................................................................. 46
Table 21: Full Strength Pull-Up Current (mA) .................................................................................................. 47
Table 22: Reduced Strength Pull-Down Current (mA) ...................................................................................... 48
Table 23: Reduced Strength Pull-Up Current (mA) .......................................................................................... 49
Table 24: Input Clamp Characteristics ............................................................................................................ 50
Table 25: Address and Control Balls ................................................................................................................ 51
Table 26: Clock, Data, Strobe, and Mask Balls ................................................................................................. 51
Table 27: AC Input Test Conditions ................................................................................................................ 52
Table 28: DDR2-400/533 Setup and Hold Time Derating Values ( tIS and tIH) .................................................... 54
Table 29: DDR2-667/800/1066 Setup and Hold Time Derating Values ( tIS and tIH) ........................................... 55
Table 30: DDR2-400/533 tDS, tDH Derating Values with Differential Strobe ...................................................... 58
Table 31: DDR2-667/800/1066 tDS, tDH Derating Values with Differential Strobe ............................................. 59
Table 32: Single-Ended DQS Slew Rate Derating Values Using tDSb and tDHb ................................................... 60
Table 33: Single-Ended DQS Slew Rate Fully Derated (DQS, DQ at V REF) at DDR2-667 ...................................... 60
Table 34: Single-Ended DQS Slew Rate Fully Derated (DQS, DQ at V REF) at DDR2-533 ...................................... 61
Table 35: Single-Ended DQS Slew Rate Fully Derated (DQS, DQ at V REF) at DDR2-400 ...................................... 61
Table 36: Truth Table – DDR2 Commands ...................................................................................................... 66
Table 37: Truth Table – Current State Bank n – Command to Bank n ................................................................ 67
Table 38: Truth Table – Current State Bank n – Command to Bank m ............................................................... 69
Table 39: Minimum Delay with Auto Precharge Enabled ................................................................................. 70
Table 40: Burst Definition .............................................................................................................................. 74
Table 41: READ Using Concurrent Auto Precharge .......................................................................................... 94
Table 42: WRITE Using Concurrent Auto Precharge ....................................................................................... 100
Table 43: Truth Table – CKE .......................................................................................................................... 115
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‹ 2003 Micron Technology, Inc. All rights reserved.
256Mb: x4, x8, x16 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_
L
CK
H
Refreshing
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
READ
A
W
AD
RIT
W
RE
RIT
WRITE
Writing
READ
Reading
WRITE
REA
ITE
DA
A
E_
PR
,
E
A
PRE, PRE_A
PR
E_
PR
Writing
with
auto
precharge
READ A
E,
PR
WRITE A
A
WR
Reading
with
auto
precharge
Precharging
Note:
PDF: 09005aef8117c187
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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.
8
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‹ 2003 Micron Technology, Inc. All rights reserved.
256Mb: x4, x8, x16 DDR2 SDRAM
Functional Description
Functional Description
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,
one-clock-cycle data transfer at the internal DRAM core and four corresponding n-bitwide, 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 T C exceeds 85°C; this also requires
use of the high-temperature self refresh option. Additionally, ODT resistance, input/
output impedance and IDD values must be derated when T C is < 0°C or > 85°C.
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Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
256Mb: x4, x8, x16 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 T C 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 T C 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 (DQ[7:0]), DM refers to LDM and DQS refers to LDQS. For the upper byte (DQ[15:8]), DM refers to UDM and DQS refers to UDQS.
• A x16 device's DQ bus is comprised of two bytes. If only one of the bytes needs to be
used, use the lower byte for data transfers and terminate the upper byte as noted:
–
–
–
–
Connect UDQS to ground via 1k˖* resistor
Connect UDQS# to V DD via 1k˖* resistor
Connect UDM to V DD via 1k˖* resistor
Connect DQ[15:8] individually to either V SS or V DD via 1k˖* resistors, or float
DQ[15:8].
*If ODT is used, 1k˖ resistor should be changed to 4x that of the selected ODT.
• 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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256MbDDR2.pdf - Rev. N 7/11 EN
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Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
256Mb: x4, x8, x16 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: 64 Meg x 4 Functional Block Diagram
ODT
CS#
RAS#
CAS#
WE#
Control
logic
Command
decode
CKE
CK
CK#
Mode
registers
15
Refresh 13
counter
Row- 13
address
MUX
13
Bank 3
Bank 3
Bank 2
Bank 2
Bank
1
Bank 1
Bank 0
Bank 0
rowaddress 8192
memory
latch and
array
decoder
(8192 x 512 x 16)
Column 0, Column 1
4
4
16 READ
4
latch
4
8192
A[12:0],
BA[1:0]
Address
15 register
2
I/O gating
DM mask logic
Bank
control
logic
512
(x16)
Column
decoder
11
Columnaddress
counter/
latch
9
2
4
Data
DRVRS
ODT control VDDQ
sw1 sw2 sw3
sw1
sw2 sw3
R1
R2
R3
R1
R2
R3
sw1
sw2 sw3
2
DQ[3:0]
DQS, DQS#
Input
registers
1
1
1
1
16
2
DLL
MUX
DQS
generator
Sense amplifiers
CK, CK#
R1
R2
R3
R1
R2
R3
sw1
sw2 sw3
4
WRITE
FIFO Mask 1
1
and
16
drivers
4
Internal
CK out
CK, CK#
16 4
CK in
Data 4
4
R1
R2
R3
4
4
R1
R2
R3
1
1
1
4
4
DQS, DQS#
RCVRS
4
DM
Column 0, Column 1
2
VSSQ
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256Mb: x4, x8, x16 DDR2 SDRAM
Functional Block Diagrams
Figure 4: 32 Meg x 8 Functional Block Diagram
ODT
CS#
RAS#
CAS#
WE#
Control
logic
Command
decode
CKE
CK
CK#
Mode
registers
15
Refresh 13
Row- 13
counter
address
MUX
13
Bank 3
Bank 2
Bank 1
Bank 0
rowaddress 8192
latch and
decoder
Bank 3
Bank 2
Bank 1
Bank 0
32
Memory
array
(8192 x 256 x 32)
8
8
READ 8
latch
8
8192
A[12:0],
BA[1:0]
Address
15 register
2
10
I/O gating
DM mask logic
Bank
control
logic
Columnaddress
counter/
latch
256
(x32)
8
2
Column
decoder
32
ODT control VDDQ
sw1 sw2 sw3
DLL
MUX
sw1
8
DRVRS
Data
DQS
generator
Sense amplifiers
2
CK, CK#
Column 0, Column 1
2
sw2 sw3
R1
R2
R3
R1
R2
R3
sw1
sw2 sw3
DQ[7:0]
DQS, DQS#
Input
registers
1
1
1
1
R1
R2
R3
DQS, DQS#
R1
R2
R3
RDQS#
sw1
sw2 sw3
4
WRITE
FIFO Mask 1
1
32
and
drivers
8
Internal
CK out
32 8
CK, CK#
CK in
Data 8
8
R1
R2
R3
8
8
R1
R2
R3
1
1
1
8
8
RCVRS
8
RDQS
DM
Column 0, Column 1
2
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12
VSSQ
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256Mb: x4, x8, x16 DDR2 SDRAM
Functional Block Diagrams
Figure 5: 16 Meg x 16 Functional Block Diagram
ODT
CKE
CK
CK#
Command
decode
Control
logic
CS#
RAS#
CAS#
WE#
Mode
registers
Refresh 13
counter
15
13
Row- 13
address
MUX
64
READ
latch
64
A[12:0],
BA[1:0]
15
Address
register
2
9
I/O gating
DM mask logic
Bank
control
logic
Columnaddress
counter/
latch
128
(x64)
7
2
Column
decoder
ODT control VDDQ
sw1 sw2 sw3
DLL
16
16
16 MUX
16
16
Data
DRVRS
sw1
sw2 sw3
R1
R2
R3
R1
R2
R3
sw1
sw2 sw3
DQ[15:0]
4
8192
2
CK, CK#
Column 0, Column 1
Bank 3
Bank 3
Bank 2
Bank 2
Bank 1
Bank 1
Bank 0
Bank 0
rowaddress 8192
Memory
latch and
array
decoder
(8192 x 128 x 64)
Sense amplifiers
DQS
generator UDQS, UDQS#
Input LDQS, LDQS#
registers
2
2
8
WRITE
FIFO Mask
64 and
drivers
Internal
CK out
64
CK, CK#
CK in
Data
Column 0, Column 1
R1
R2
R3
R1
R2
R3
sw1
sw2 sw3
2
2
2
2
2
2
16
16
16
16
16
16
R1
R2
R3
16
R1
R2
R3
16
2
UDQS, UDQS#
LDQS, LDQS#
RCVRS
16
UDM, LDM
4
VSSQ
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256Mb: x4, x8, x16 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
RFU
RFU
RFU
D
E
F
G
RFU
H
VDD
J
VSS
K
VSS
L
VDD
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256Mb: x4, x8, x16 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
RFU
A
VSSQ UDQS#/NU VDDQ
B
C
D
E
VSSQ LDQS#/NU VDDQ
F
G
H
J
K
L
RFU
M
VDD
N
VSS
P
VSS
R
VDD
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256Mb: x4, x8, x16 DDR2 SDRAM
Ball Assignments and Descriptions
Table 3: FBGA 60-Ball – x4, x8 and 84-Ball – x16 Descriptions
Symbol
Type
Description
A[12:0]
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[1:0]) or
all banks (A10 HIGH). The address inputs also provide the op-code during a LOAD MODE
command.
BA0, BA1
Input
Bank address inputs: BA[1:0] define to which bank an ACTIVATE, READ, WRITE, or PRECHARGE command is being applied. BA[1:0] 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 control, command, and address 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 enables (registered HIGH) and disables (registered LOW) internal circuitry and clocks on the DDR2 SDRAM. The specific circuitry that is enabled/disabled is dependent on the DDR2 SDRAM configuration and operating mode. Taking CKE LOW provides precharge power-down and SELF REFRESH operations (all banks idle), or ACTIVATE power-down
(row active in any bank). CKE is synchronous for power-down entry, power-down exit, output disable, and 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 sampled HIGH, along with the input data, 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 the lower byte DQ[7:0], and UDM is DM for the
upper byte DQ[15:8].
ODT
Input
On-die termination: ODT enables (registered HIGH) and disables (registered LOW) termination resistance internal to the DDR2 SDRAM. When enabled, ODT is only applied to each
of the following balls for the x4 configuration: DQ[3:0], DQS, DQS#, and DM; for the x8 configuration: DQ[7:0], DQS, DQS#, RDQS, RDQS#, and DM; and for the x16 configuration:
DQ[15:0], LDM, UDM, LDQS, LDQS#, UDQS, and UDQS#. 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
Data input/output: Bidirectional data bus for the 16 Meg x 16 configuration.
Bidirectional data bus for the 64 Meg x 4 configuration.
Bidirectional data bus for the 32 Meg x 8 configuration.
DQS, DQS#
I/O
Data strobe: DQS# is only used when differential data strobe mode is enabled via the
LOAD MODE command. Output with read data. Edge-aligned with read data. Input with
write data. Center-aligned with write data.
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256Mb: x4, x8, x16 DDR2 SDRAM
Ball Assignments and Descriptions
Table 3: FBGA 60-Ball – x4, x8 and 84-Ball – x16 Descriptions (Continued)
Symbol
Type
LDQS, LDQS#
I/O
Description
Data strobe for lower byte: LDQS# is only used when differential data strobe mode is enabled via the LOAD MODE command. Output with read data. Edge-aligned with read data.
Input with write data. Center-aligned with write data.
UDQS, UDQS#
I/O
Data strobe for upper byte: UDQS# is only used when differential data strobe mode is enabled via the LOAD MODE command. Output with read data. Edge-aligned with read data.
Input with write data. Center-aligned with write data.
RDQS, RDQS#
Output
Redundant data strobe: For the x8 configuration 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: 1.8V ±0.1V.
VDDL
Supply
DLL power supply: 1.8V ±0.1V.
VDDQ
Supply
DQ power supply: 1.8V ±0.1V. Isolated on the device for improved noise immunity.
VREF
Supply
SSTL_18 reference voltage (VDDQ/2).
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: For the x4 configuration, these balls are no function. For the x8 configuration,
they are used as DQ[7:4].
NU
–
Not used: If EMR(E10) = 0: For the x4 configuration, A2 = NU and A8 = NU. For the x8 configuration, A2 = RDQS# and A8 = DQS#. If EMR(E10) = 1: For the x4 configuration, A2 = NU
and A8 = NU. For the x8 configuration, A2 = NU and A8 = NU.
NU
–
Not Used: If EMR(E10) = 0: For the x16 configuration, A8 = UDQS# and E8 = LDQS#. If
EMR(E10) = 1: For the x16 configuration, A8 = NU and E8 = NU.
RFU
–
Reserved for future use: Bank address BA2, row address bits A[15:13].
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256Mb: x4, x8, x16 DDR2 SDRAM
Packaging
Packaging
Package Dimensions
Figure 8: 84-Ball, FBGA Package (8mm x 14mm) – x16
0.8 ±0.1
Seating plane
C
0.12 C
0.80
TYP
Ball A1 ID
0.25 MIN
Ball A1 ID location
84X Ø0.45
Solder ball material:
Pb-free – (SAC305) SnAgCu
Pb – (Eutectic) SnPbAg
Dimensions apply to solder
balls post-reflow.
CL
11.2
14.0 ±0.15
0.80 TYP
CL
6.4
8.0 ±0.15
1.2 MAX
Note:
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1. All dimensions are in millimeters.
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256Mb: x4, x8, x16 DDR2 SDRAM
Packaging
Figure 9: 60-Ball, FBGA Package (8mm x 12mm) – x4, x8
0.8 ±0.1
Seating plane
C
0.12 C
0.8 TYP
0.25 MIN
Ball A1 ID
60X Ø0.45
Solder ball material:
Pb-free – (SAC305) SnAgCu
Pb – (Eutectic) SnPbAg
Dimensions apply to solder
balls post-reflow.
Ball A1 ID location
12.0 ±0.15
CL
8.0
0.8 TYP
CL
6.4
8.0 ±0.15
Note:
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1.2 MAX
1. All dimensions are in millimeters.
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256Mb: x4, x8, x16 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: Address balls, bank address balls, 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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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. ˂C are not pass/fail parameters; they are targets.
4. Reduce MAX limit by 0.5pF for the -3 speed device.
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256Mb: x4, x8, x16 DDR2 SDRAM
Electrical Specifications – Absolute Ratings
Electrical Specifications – Absolute Ratings
Stresses greater than those listed in Table 5 may cause permanent damage to the device.
This is a stress rating only, and functional operation of the device at these or any other
conditions outside those indicated in the operational sections of this specification is
not implied. Exposure to absolute maximum rating conditions for extended periods
may adversely affect reliability.
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
VIN, VOUT –0.5
3
Voltage on any ball relative to VSS
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:
2.3
V
II
–5
5
μA
IOZ
–5
5
μA
IVREF
–2
2
μA
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 DRAM die shrinks, consider using final target theta values (rather than existing values) to account for increased thermal impedances from the die size
reduction.
The DDR2 SDRAM device’s safe junction temperature range can be maintained when
the T C 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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256Mb: x4, x8, x16 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
TC
–40
105
°C
2, 3, 4
TA
–40
105
°C
4, 5
Operating temperature: automotive
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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256Mb: x4, x8, x16 DDR2 SDRAM
Electrical Specifications – Absolute Ratings
Table 7: Thermal Impedance
˥ JA (°C/W)
˥ JA (°C/W)
˥ JA (°C/W)
Die Revision Package Substrate Airflow = 0m/s Airflow = 1m/s Airflow = 2m/s
B1
60-ball
84-ball
Last shrink
target2
60-ball
84-ball
Notes:
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˥ JB (°C/W)
˥ JC (°C/W)
4.4
2-layer
59.0
46.7
43.1
25.0
4-layer
37.8
32.5
30.7
20.5
2-layer
53.6
40.0
35.2
20.0
4-layer
36.6
29.9
27.5
19.2
2-layer
65
48
45
30
4-layer
45
38
34
27
2-layer
55
45
37
28
4-layer
40
35
30
27
5.2
5.0
6.0
1. Thermal resistance data is based on a number of samples from multiple lots and should
be viewed as a typical number.
2. This is an estimate; simulated number and actual results could vary.
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256Mb: x4, x8, x16 DDR2 SDRAM
Electrical Specifications – IDD Parameters
Electrical Specifications – IDD Parameters
IDD Specifications and Conditions
Table 8: General IDD Parameters
IDD Parameters
-3
-37E
-5E
Units
CL (IDD)
5
4
3
tCK
15
15
15
ns
60
60
55
ns
tRCD
tRC
(IDD)
(IDD)
tRRD
(IDD) - x4/x8 (1KB)
7.5
7.5
7.5
ns
tRRD
(IDD) - x16 (2KB)
10
10
10
ns
3
3.75
5
ns
ns
tCK
(IDD)
tRAS
MIN (IDD)
45
45
40
tRAS
MAX (IDD)
70,000
70,000
70,000
ns
15
15
15
ns
tRP
(IDD)
tRFC
(IDD - 256Mb)
75
75
75
ns
tRFC
(IDD - 512Mb)
105
105
105
ns
tRFC
(IDD - 1Gb)
127.5
127.5
127.5
ns
tRFC
(IDD - 2Gb)
195
195
195
ns
tFAW
(IDD) - x4/x8 (1KB)
Defined by pattern in Table 9
ns
tFAW
(IDD) - x16 (2KB)
Defined by pattern in Table 9
ns
IDD7 Conditions
The detailed timings are shown below for IDD7. Where general I DD parameters in Table 8
conflict with pattern requirements of Table 9, then Table 9 requirements take precedence.
Table 9: IDD7 Timing Patterns (4-Bank Interleave READ Operation)
Speed Grade
IDD7 Timing Patterns
Timing patterns for 4-bank x4/x8/x16 devices
-3
Notes:
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A0 RA0 D D A1 RA1 D D A2 RA2 D D A3 RA3 D D D D D D
-37E
A0 RA0 D A1 RA1 D A2 RA2 D A3 RA3 D D D D D
-5E
A0 RA0 A1 RA1 A2 RA2 A3 RA3 D D D
1. A = active; RA = read auto precharge; D = deselect.
2. All banks are being interleaved at tRC (IDD) without violating tRRD (IDD) using a BL = 4.
3. Control and address bus inputs are STABLE during DESELECTs.
24
Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
256Mb: x4, x8, x16 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
-3
-37E
-5E
Units
Operating one bank active-precharge current:
= tCK (IDD), tRC = tRC (IDD), tRAS = tRAS MIN (IDD);
CKE is HIGH, CS# is HIGH between valid commands;
Address bus inputs are switching; Data bus inputs
are switching
IDD0
x4, x8
90
80
75
mA
x16
90
80
75
Operating one bank active-read-precharge
current: IOUT = 0mA; BL = 4, CL = CL (IDD), AL = 0; tCK
= tCK (IDD), tRC = tRC (IDD), tRAS = tRAS MIN (IDD),
tRCD = tRCD (I ); CKE is HIGH, CS# is HIGH between
DD
valid commands; Address bus inputs are switching;
Data pattern is same as IDD4W
IDD1
x4, x8
100
90
85
x16
100
90
85
Precharge power-down current: All banks idle;
= tCK (IDD); CKE is LOW; Other control and address bus inputs are stable; Data bus inputs are floating
IDD2P
x4, x8, x16
5
5
5
mA
Precharge quiet standby current: All banks idle;
tCK = tCK (I ); CKE is HIGH, CS# is HIGH; Other conDD
trol and address bus inputs are stable; Data bus inputs are floating
IDD2Q
x4, x8
40
35
25
mA
x16
50
35
25
Precharge standby current: All banks idle;
= 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
30
x16
40
35
30
Active power-down current: All banks open;
= tCK (IDD); CKE is LOW; Other control and address bus inputs are stable; Data bus inputs are floating
IDD3Pf
Fast PDN exit
MR12 = 0
30
25
20
IDD3Ps
Slow PDN exit
MR12 = 1
6
6
6
Active standby current: All banks open;
tCK= tCK (I ), tRAS = tRAS MAX (I ), tRP = tRP (I );
DD
DD
DD
CKE is HIGH, CS# is HIGH between valid commands;
Other control and address bus inputs are switching;
Data bus inputs are switching
IDD3N
x4, x8
50
40
30
x16
55
40
30
Operating burst write current: All banks open;
Continuous burst writes; BL = 4, CL = CL (IDD), AL = 0;
tCK = tCK (I ), tRAS = tRAS MAX (I ), tRP = tRP (I );
DD
DD
DD
CKE is HIGH, CS# is HIGH between valid commands;
Address bus inputs are switching; Data bus inputs
are switching
IDD4W
x4, x8
190
160
125
x16
215
180
140
Operating burst read current: All banks open;
Continuous burst reads, IOUT = 0mA; BL = 4,
CL = CL (IDD), AL = 0; tCK = tCK (IDD),
tRAS = tRAS MAX (I ), tRP = tRP (I ); CKE is HIGH,
DD
DD
CS# is HIGH between valid commands; Address bus
inputs are switching; Data bus inputs are switching
IDD4R
x4, x8
180
150
115
x16
190
160
120
tCK
mA
tCK
tCK
tCK
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25
mA
mA
mA
mA
mA
Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
256Mb: x4, x8, x16 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
-3
-37E
-5E
Units
=
(IDD); REFRESH
Burst refresh current:
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
180
170
165
mA
x16
180
170
165
Self refresh current: CK and CK# at 0V; CKE ื 0.2V;
Other control and address bus inputs are floating;
Data bus inputs are floating
IDD6
x4, x8, x16
5
5
5
3
3
3
x4, x8
250
240
230
x16
320
300
290
tCK
tCK
Operating bank interleave read current: All
bank interleaving reads, IOUT = 0mA; BL = 4, CL = CL
(IDD), AL = tRCD (IDD) - 1 x tCK (IDD); tCK = tCK (IDD),
tRC = tRC (I ), tRRD = tRRD (I ), tRCD = tRCD (I );
DD
DD
DD
CKE is HIGH, CS# is HIGH between valid commands;
Address bus inputs are stable during deselects; Data
bus inputs are switching; See IDD7 Conditions
(page 24) for details
Notes:
IDD6L
IDD7
mA
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#.
5. Definitions for IDD conditions:
1.
2.
3.
4.
VIN ื VIL(AC)max
VIN ุ VIH(AC)min
Inputs stable at a HIGH or LOW level
Inputs at VREF = VDDQ/2
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 or on AT-option devices when operated outside of the range 0°C ื TC ื 85°C:
LOW
HIGH
Stable
Floating
Switching
When
TC ื 0°C
When
TC ุ 85°C
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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)
26
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‹ 2003 Micron Technology, Inc. All rights reserved.
PDF: 09005aef8117c187
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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 = 1.8V ±0.1V, VDD = 1.8V ±0.1V
AC Characteristics
-187E
-25E
-25
-3E
-3
-37E
-5E
Parameter
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
–
–
–
–
–
–
–
–
–
–
2.5
8.0
–
–
–
–
–
–
–
–
8.0
3.0
8.0
3.0
8.0
–
–
–
–
3.0
8.0
3.75
8.0
3.75
8.0
5.0
8.0
5.0
8.0
5.0
8.0
5.0
8.0
5.0
8.0
0.52
0.48
0.52
0.48
0.52
0.48
0.52
0.48
0.52
0.48
0.52
0.48
CL = 7
(avg) 1.875
8.0
–
–
CL = 6
tCK
(avg)
2.5
8.0
2.5
8.0
CL = 5
tCK
(avg)
2.5
8.0
2.5
8.0
3.0
CL = 4
tCK
(avg)
3.75
8.0
3.75
8.0
3.75
8.0
CL = 3
tCK
(avg)
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
CK low-level width
tCL
(avg)
0.48
0.52
0.48
0.52
0.48
0.52
0.48
Clock
cycle time
Clock
Symbol
tCK
Half clock period
tHP
tCH
MIN = lesser of
and
MAX = n/a
tCL
Max Units Notes
ns
6, 7, 8,
9
0.52
tCK
10
0.52
tCK
ps
27
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
256Mb: x4, x8, x16 DDR2 SDRAM
AC Timing Operating Specifications
Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
Absolute tCK
11
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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 = 1.8V ±0.1V, VDD = 1.8V ±0.1V
AC Characteristics
-187E
-25E
-25
-3E
-3
-37E
-5E
Symbol
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max Units Notes
Period jitter
Parameter
tJITper
–90
90
–100
100
–100
100
–125
125
–125
125
–125
125
–125
125
Half period
tJITdty
–75
75
–100
100
–100
100
–125
125
–125
125
–125
125
–150
150
Clock Jitter
Cycle to cycle
28
Cumulative error,
2 cycles
tERR
Cumulative error,
3 cycles
tERR
Cumulative error,
4 cycles
tERR
Cumulative error,
5 cycles
tERR
180
200
200
250
250
250
250
12
ps
13
ps
14
2per
–132
132
–150
150
–150
150
–175
175
–175
175
–175
175
–175
175
ps
15
3per
–157
157
–175
175
–175
175
–225
225
–225
225
–225
225
–225
225
ps
15
4per
–175
175
–200
200
–200
200
–250
250
–250
250
–250
250
–250
250
ps
15
5per
–188
188
–200
200
–200
200
–250
250
–250
250
–250
250
–250
250
ps
15, 16
–250
250
–300
300
–300
300
–350
350
–350
350
–350
350
–350
350
ps
15, 16
Cumulative error,
6–10 cycles
tERR
Cumulative error,
11–50 cycles
tERR
11–
–425
425
–450
450
–450
450
–450
450
–450
450
–450
450
–450
450
ps
15
50per
tDQSCK
–300
300
–350
350
–350
350
–400
400
–400
400
–450
450
–500
500
ps
19
DQS output access
time from CK/CK#
6–
10per
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
CK/CK# to DQS
Low-Z
1
256Mb: x4, x8, x16 DDR2 SDRAM
AC Timing Operating Specifications
Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
Data Strobe-Out
tJITcc
ps
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 = 1.8V ±0.1V, VDD = 1.8V ±0.1V
AC Characteristics
-187E
-25E
-25
-3E
-3
-37E
-5E
Parameter
Data Strobe-In
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256MbDDR2.pdf - Rev. N 7/11 EN
Table 11: AC Operating Specifications and Conditions (Continued)
Symbol
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max Units Notes
29
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
Write preamble
setup time
WRITE command
to first DQS
transition
256Mb: x4, x8, x16 DDR2 SDRAM
AC Timing Operating Specifications
Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
DQS rising edge to
CK rising edge
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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 = 1.8V ±0.1V, VDD = 1.8V ±0.1V
AC Characteristics
-187E
-25E
-25
-3E
-3
-37E
-5E
Symbol
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max Units Notes
tAC
–350
350
–400
400
–400
400
–450
450
–450
450
–500
500
–600
600
ps
19
tDQSQ
–
175
–
200
–
200
–
240
–
240
–
300
–
350
ps
26, 27
DQ hold from next
DQS strobe
tQHS
–
250
–
300
–
300
–
340
–
340
–
400
–
450
ps
28
DQ–DQS hold, DQS
to first DQ not valid
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
MIN = tQH - tDQSQ
MAX = n/a
ns
26, 27
Data-Out
DQS–DQ skew,
DQS to last DQ
valid, per group,
per access
Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
Data-In
30
2
Data valid output
window
DVW
DQ and DM input
setup time to DQS
tDSb
0
–
50
–
50
–
100
–
100
–
100
–
150
–
ps
26, 30,
31
DQ and DM input
hold time to DQS
tDHb
75
–
125
–
125
–
175
–
175
–
225
–
275
–
ps
26, 30,
31
DQ and DM input
setup time to DQS
tDSa
200
–
250
–
250
–
300
–
300
–
350
–
400
–
ps
26, 30,
31
DQ and DM input
hold time to DQS
tDHa
200
–
250
–
250
–
300
–
300
–
350
–
400
–
ps
26, 30,
31
DQ and DM input
pulse width
tDIPW
tCK
18, 32
MIN = 0.35 × tCK
MAX = n/a
256Mb: x4, x8, x16 DDR2 SDRAM
AC Timing Operating Specifications
Parameter
DQ output access
time from CK/CK#
PDF: 09005aef8117c187
256MbDDR2.pdf - Rev. N 7/11 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 = 1.8V ±0.1V, VDD = 1.8V ±0.1V
AC Characteristics
-187E
-25E
-25
-3E
-3
-37E
-5E
Parameter
Symbol
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Input setup time
tISb
125
–
175
–
175
–
200
–
200
–
250
–
350
Input hold time
tIHb
200
–
250
–
250
–
275
–
275
–
375
–
Input setup time
tISa
325
–
375
–
375
–
400
–
400
–
500
–
Input hold time
tIHa
325
–
375
–
375
–
400
–
400
–
500
–
600
Input pulse width
tIPW
0.6
–
0.6
–
0.6
–
0.6
–
0.6
–
0.6
–
tRC
54
–
55
–
55
–
54
–
55
–
55
–
ACTIVATE-to-READ
or WRITE delay
tRCD
13.125
–
12.5
–
15
–
12
–
15
–
15
ACTIVATE-toPRECHARGE delay
tRAS
40
70K
40
70K
40
70K
40
70K
40
70K
tRP
13.125
–
12.5
–
15
–
12
–
15
–
–
12
–
15
–
31
PRECHARGE period
–
ps
475
–
ps
31, 33
600
–
ps
31, 33
–
ps
31, 33
0.6
–
tCK
18, 32
55
–
ns
18, 34,
51
–
15
–
ns
18
40
70K
40
70K
ns
18, 34,
35
15
–
15
–
ns
18, 36
15
–
15
–
PRECHARGE
ALL period
<1Gb
tRPA
13.125
–
12.5
–
15
ุ1Gb
tRPA
15
–
15
–
17.5
ACTIVATE
-toACTIVATE
delay
different
bank
x4, x8
tRRD
7.5
–
7.5
–
7.5
–
7.5
–
7.5
–
7.5
–
7.5
x16
tRRD
10
–
10
–
10
–
10
–
10
–
10
–
4-bank
activate
period
(ุ1Gb)
x4, x8
tFAW
35
–
35
–
35
–
37.5
–
37.5
–
37.5
x16
tFAW
45
–
45
–
45
–
50
–
50
–
50
15
18
31, 33
ns
18, 36
ns
18, 36
–
ns
18, 37
10
–
ns
18, 37
–
37.5
–
ns
18, 38
–
50
–
ns
18, 38
18.75
20
256Mb: x4, x8, x16 DDR2 SDRAM
AC Timing Operating Specifications
Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
Command and Address
ACTIVATE-toACTIVATE delay,
same bank
Max Units Notes
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 = 1.8V ±0.1V, VDD = 1.8V ±0.1V
AC Characteristics
-187E
-25E
-25
-3E
-3
-37E
-5E
Parameter
Command and Address
PDF: 09005aef8117c187
256MbDDR2.pdf - Rev. N 7/11 EN
Table 11: AC Operating Specifications and Conditions (Continued)
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
tRTP
7.5
–
7.5
–
7.5
–
7.5
–
7.5
–
7.5
–
7.5
–
ns
18, 37,
39
CAS#-to-CAS#
delay
tCCD
2
–
2
–
2
–
2
–
2
–
2
–
2
–
tCK
18
Write recovery
time
tWR
15
–
15
–
15
–
15
–
15
–
15
–
15
–
ns
18, 37
Write AP recovery
+ precharge time
tDAL
tWR
–
tWR
–
tWR
–
tWR
–
tWR
–
tWR
–
tWR
–
ns
40
Internal WRITE-toREAD delay
tWTR
7.5
–
7.5
–
7.5
–
7.5
–
7.5
–
7.5
–
10
–
ns
18, 37
LOAD MODE cycle
time
tMRD
2
–
2
–
2
–
2
–
2
–
2
–
2
–
tCK
18
tRFC
75
–
75
–
75
–
75
–
75
–
75
–
75
–
ns
18, 41
512Mb
105
–
105
–
105
–
105
–
105
–
105
–
105
–
1Gb
127.5
–
127.5
–
127.5
–
127.5
–
127.5
–
127.5
–
127.5
–
2Gb
195
–
195
–
195
–
195
–
195
–
195
–
195
–
–
7.8
–
7.8
–
7.8
–
7.8
–
7.8
–
7.8
–
7.8
μs
18, 41
IT
–
3.9
–
3.9
–
3.9
–
3.9
–
3.9
–
3.9
–
3.9
μs
18, 41
AT
–
3.9
–
3.9
–
3.9
–
3.9
–
3.9
–
3.9
–
3.9
μs
18, 41
ns
42
Refresh
256Mb
Average periodic
refresh
(commercial)
+
tRP
tREFI
Average periodic
refresh
(industrial)
tREFI
Average periodic
refresh
(automotive)
tREFI
CKE LOW to CK,
CK# uncertainty
tDELAY
+
tRP
+
tRP
+
tRP
+
tRP
MIN limit = tIS + tCK + tIH
MAX limit = n/a
+
tRP
+
Max Units Notes
tRP
256Mb: x4, x8, x16 DDR2 SDRAM
AC Timing Operating Specifications
REFRESHtoACTIVATE
or to
-REFRESH
interval
32
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‹ 2003 Micron Technology, Inc. All rights reserved.
Symbol
Internal READ-toPRECHARGE delay
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 = 1.8V ±0.1V, VDD = 1.8V ±0.1V
AC Characteristics
-187E
-25E
-25
-3E
-3
-37E
-5E
Parameter
33
Power-Down
Self Refresh
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Table 11: AC Operating Specifications and Conditions (Continued)
Symbol
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max Units Notes
Exit SELF REFRESH
to nonREAD
command
tXSNR
MIN limit = tRFC (MIN) + 10
MAX limit = n/a
ns
Exit SELF REFRESH
to READ command
tXSRD
MIN limit = 200
MAX limit = n/a
tCK
18
Exit SELF REFRESH
timing reference
tISXR
MIN limit = tIS
MAX limit = n/a
ps
33, 43
Exit active
powerdown to
READ
command
MR12
=0
tXARD
MR12
=1
CKE MIN
HIGH/LOW time
tXP
tCKE
–
2
–
2
–
2
–
2
–
2
–
2
–
tCK
18
10 AL
–
8 - AL
–
8 - AL
–
7 - AL
–
7 - AL
–
6 - AL
–
6 - AL
–
tCK
18
3
–
2
–
2
–
2
–
2
–
2
–
2
–
tCK
18
tCK
18, 44
MIN = 3
MAX = n/a
256Mb: x4, x8, x16 DDR2 SDRAM
AC Timing Operating Specifications
Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
Exit precharge
power-down and
active power-down
to any
nonREAD
command
3
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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 = 1.8V ±0.1V, VDD = 1.8V ±0.1V
AC Characteristics
-187E
-25E
-25
-3E
-3
-37E
-5E
Symbol
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
Min
ODT to powerdown entry latency
Parameter
tANPD
4
–
3
–
3
–
3
–
3
–
3
–
3
–
tCK
18
ODT power-down
exit latency
tAXPD
11
–
10
–
10
–
8
–
8
–
8
–
8
–
tCK
18
ODT turn-on delay
tAOND
2
tCK
18
ODT turn-off delay
tAOFD
2.5
tCK
18, 45
ps
19, 46
ps
47, 48
ps
49
ODT turn-on
tAON
tAC
tAC
ODT
(MIN) (MAX)
+
2575
= tAC
MIN
(MIN)
MAX = tAC (MAX) + 600
= tAC
(MIN)
MIN
MAX = tAC (MAX) + 700
tAC
Max Units Notes
(MIN)
MIN =
MAX = tAC (MAX) + 1000
34
tAOF
ODT turn-on
(power-down
mode)
tAONPD
ODT turn-off
(power-down
mode)
tAOFPD
MIN = tAC (MIN) + 2000
MAX = 2.5 × tCK + tAC (MAX) + 1000
ps
tMOD
MIN = 12
MAX = n/a
ns
ODT enable from
MRS command
MIN = tAC (MIN)
MAX = tAC (MAX) + 600
tAC
2×
(MIN)
+
+ 2000 tAC
(MAX)
+
1000
tCK
MIN = tAC (MIN) + 2000
MAX = 2 × tCK + tAC (MAX) + 1000
18, 50
256Mb: x4, x8, x16 DDR2 SDRAM
AC Timing Operating Specifications
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ODT turn-off
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Notes:
35
256Mb: x4, x8, x16 DDR2 SDRAM
AC Timing Operating Specifications
Micron Technology, Inc. reserves the right to change products or specifications without notice.
‹ 2003 Micron Technology, Inc. All rights reserved.
1. All voltages are referenced to VSS.
2. Tests for AC timing, IDD, and electrical AC and DC characteristics may be conducted at nominal reference/supply
voltage levels, but the related specifications and the operation of the device are warranted for the full voltage
range specified. ODT is disabled for all measurements that are not ODT-specific.
3. Outputs measured with equivalent load (see Figure 14 (page 45)).
4. AC timing and IDD tests may use a VIL-to-VIH swing of up to 1.0V in the test environment, and parameter specifications are guaranteed for the specified AC input levels under normal use conditions. The slew rate for the input
signals used to test the device is 1.0 V/ns for signals in the range between VIL(AC) and VIH(AC). Slew rates other than
1.0 V/ns may require the timing parameters to be derated as specified.
5. The AC and DC input level specifications are as defined in the SSTL_18 standard (that is, the receiver will effectively switch as a result of the signal crossing the AC input level and will remain in that state as long as the signal
does not ring back above [below] the DC input LOW [HIGH] level).
6. CK and CK# input slew rate is referenced at 1 V/ns (2 V/ns if measured differentially).
7. Operating frequency is only allowed to change during self refresh mode (see Figure 77 (page 120)), precharge
power-down mode, or system reset condition (see Reset (page 121)). SSC allows for small deviations in operating
frequency, provided the SSC guidelines are satisfied.
8. The clock’s tCK (AVG) is the average clock over any 200 consecutive clocks and tCK (AVG) MIN is the smallest clock
rate allowed (except for a deviation due to allowed clock jitter). Input clock jitter is allowed provided it does not
exceed values specified. Also, the jitter must be of a random Gaussian distribution in nature.
9. Spread spectrum is not included in the jitter specification values. However, the input clock can accommodate
spread spectrum at a sweep rate in the range 8–60 kHz with an additional one percent tCK (AVG); however, the
spread spectrum may not use a clock rate below tCK (AVG) MIN or above tCK (AVG) MAX.
10. MIN (tCL, tCH) refers to the smaller of the actual clock LOW time and the actual clock HIGH time driven to the
device. The clock’s half period must also be of a Gaussian distribution; tCH (AVG) and tCL (AVG) must be met with
or without clock jitter and with or without duty cycle jitter. tCH (AVG) and tCL (AVG) are the average of any 200
consecutive CK falling edges. tCH limits may be exceeded if the duty cycle jitter is small enough that the absolute
half period limits (tCH [ABS], tCL [ABS]) are not violated.
11. tHP (MIN) is the lesser of tCL and tCH actually applied to the device CK and CK# inputs; thus, tHP (MIN) ุ the lesser
of tCL (ABS) MIN and tCH (ABS) MIN.
12. The period jitter (tJITper) is the maximum deviation in the clock period from the average or nominal clock allowed
in either the positive or negative direction. JEDEC specifies tighter jitter numbers during DLL locking time. During
DLL lock time, the jitter values should be 20 percent less those than noted in the table (DLL locked).
13. The half-period jitter (tJITdty) applies to either the high pulse of clock or the low pulse of clock; however, the two
cumulatively can not exceed tJITper.
14. The cycle-to-cycle jitter (tJITcc) is the amount the clock period can deviate from one cycle to the next. JEDEC specifies tighter jitter numbers during DLL locking time. During DLL lock time, the jitter values should be 20 percent
less than those noted in the table (DLL locked).
15. The cumulative jitter error (tERRnper), where n is 2, 3, 4, 5, 6–10, or 11–50 is the amount of clock time allowed to
consecutively accumulate away from the average clock over any number of clock cycles.
16. JEDEC specifies using tERR6–10per when derating clock-related output timing (see notes 19 and 48). Micron requires
less derating by allowing tERR5per to be used.
17. This parameter is not referenced to a specific voltage level but is specified when the device output is no longer
driving (tRPST) or beginning to drive (tRPRE).
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36
256Mb: x4, x8, x16 DDR2 SDRAM
AC Timing Operating Specifications
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‹ 2003 Micron Technology, Inc. All rights reserved.
18. The inputs to the DRAM must be aligned to the associated clock, that is, the actual clock that latches it in. However, the input timing (in ns) references to the tCK (AVG) when determining the required number of clocks. The following input parameters are determined by taking the specified percentage times the tCK (AVG) rather than tCK:
tIPW, tDIPW, tDQSS, tDQSH, tDQSL, tDSS, tDSH, tWPST, and tWPRE.
19. The DRAM output timing is aligned to the nominal or average clock. Most output parameters must be derated by
the actual jitter error when input clock jitter is present; this will result in each parameter becoming larger. The
following parameters are required to be derated by subtracting tERR5per (MAX): tAC (MIN), tDQSCK (MIN), tLZDQS
(MIN), tLZDQ (MIN), tAON (MIN); while the following parameters are required to be derated by subtracting
tERR
t
t
t
t
t
t
5per (MIN): AC (MAX), DQSCK (MAX), HZ (MAX), LZDQS (MAX), LZDQ (MAX), AON (MAX). The parameter
tRPRE (MIN) is derated by subtracting tJITper (MAX), while tRPRE (MAX), is derated by subtracting tJITper (MIN).
The parameter tRPST (MIN) is derated by subtracting tJITdty (MAX), while tRPST (MAX), is derated by subtracting
tJITdty (MIN). Output timings that require tERR
5per derating can be observed to have offsets relative to the clock;
however, the total window will not degrade.
20. When DQS is used single-ended, the minimum limit is reduced by 100ps.
21. tHZ and tLZ transitions occur in the same access time windows as valid data transitions. These parameters are not
referenced to a specific voltage level, but specify when the device output is no longer driving (tHZ) or begins driving (tLZ).
t
22. LZ (MIN) will prevail over a tDQSCK (MIN) + tRPRE (MAX) condition.
23. This is not a device limit. The device will operate with a negative value, but system performance could be degraded due to bus turnaround.
24. It is recommended that DQS be valid (HIGH or LOW) on or before the WRITE command. The case shown (DQS going from High-Z to logic LOW) applies when no WRITEs were previously in progress on the bus. If a previous
WRITE was in progress, DQS could be HIGH during this time, depending on tDQSS.
25. The intent of the “Don’t Care” state after completion of the postamble is that the DQS-driven signal should either
be HIGH, LOW, or High-Z, and that any signal transition within the input switching region must follow valid input
requirements. That is, if DQS transitions HIGH (above VIH[DC]min), then it must not transition LOW (below VIH[DC])
prior to tDQSH (MIN).
26. Referenced to each output group: x4 = DQS with DQ[3:0]; x8 = DQS with DQ[7:0]; x16 = LDQS with DQ[7:0]; and
UDQS with DQ[15:8].
27. The data valid window is derived by achieving other specifications: tHP (tCK/2), tDQSQ, and tQH (tQH = tHP - tQHS).
The data valid window derates in direct proportion to the clock duty cycle and a practical data valid window can
be derived.
28. tQH = tHP - tQHS; the worst case tQH would be the lesser of tCL (ABS) MAX or tCH (ABS) MAX times tCK (ABS) MIN
- tQHS. Minimizing the amount of tCH (AVG) offset and value of tJITdty will provide a larger tQH, which in turn
will provide a larger valid data out window.
29. This maximum value is derived from the referenced test load. tHZ (MAX) will prevail over tDQSCK (MAX) + tRPST
(MAX) condition.
30. The values listed are for the differential DQS strobe (DQS and DQS#) with a differential slew rate of 2 V/ns (1 V/ns
for each signal). There are two sets of values listed: tDSa, tDHa and tDSb, tDHb. The tDSa, tDHa values (for reference
only) are equivalent to the baseline values of tDSb, tDHb at VREF when the slew rate is 2 V/ns, differentially. The
baseline values, tDSb, tDHb, are the JEDEC-defined values, referenced from the logic trip points. tDSb is referenced
from VIH(AC) for a rising signal and VIL(AC) for a falling signal, while tDHb is referenced from VIL(DC) for a rising signal and VIH(DC) for a falling signal. If the differential DQS slew rate is not equal to 2 V/ns, then the baseline values
must be derated by adding the values from Table 30 (page 58) and Table 31 (page 59). If the DQS differential
strobe feature is not enabled, then the DQS strobe is single-ended and the baseline values must be derated using
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31.
32.
33.
34.
35.
36.
37.
38.
37
39.
41.
42.
43.
44.
256Mb: x4, x8, x16 DDR2 SDRAM
AC Timing Operating Specifications
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‹ 2003 Micron Technology, Inc. All rights reserved.
40.
Table 32 (page 60). Single-ended DQS data timing is referenced at DQS crossing VREF. The correct timing values
for a single-ended DQS strobe are listed in Table 33 (page 60)–Table 35 (page 61) on Table 33 (page 60),
Table 34 (page 61), and Table 35 (page 61); listed values are already derated for slew rate variations and converted from baseline values to VREF values.
VIL/VIH DDR2 overshoot/undershoot. See AC Overshoot/Undershoot Specification (page 51).
For each input signal—not the group collectively.
There are two sets of values listed for command/address: tISa, tIHa and tISb, tIHb. The tISa, tIHa values (for reference
only) are equivalent to the baseline values of tISb, tIHb at VREF when the slew rate is 1 V/ns. The baseline values,
tIS , tIH , are the JEDEC-defined values, referenced from the logic trip points. tIS is referenced from V
b
b
b
IH(AC) for a
rising signal and VIL(AC) for a falling signal, while tIHb is referenced from VIL(DC) for a rising signal and VIH(DC) for a
falling signal. If the command/address slew rate is not equal to 1 V/ns, then the baseline values must be derated
by adding the values from Table 28 (page 54) and Table 29 (page 55).
This is applicable to READ cycles only. WRITE cycles generally require additional time due to tWR during auto precharge.
READs and WRITEs with auto precharge are allowed to be issued before tRAS (MIN) is satisfied because tRAS lockout feature is supported in DDR2 SDRAM.
When a single-bank PRECHARGE command is issued, tRP timing applies. tRPA timing applies when the PRECHARGE (ALL) command is issued, regardless of the number of banks open. For 8-bank devices (ุ1Gb), tRPA (MIN)
= tRP (MIN) + tCK (AVG) (Table 11 (page 27) lists tRP [MIN] + tCK [AVG] MIN).
This parameter has a two clock minimum requirement at any tCK.
The tFAW (MIN) parameter applies to all 8-bank DDR2 devices. No more than four bank-ACTIVATE commands may
be issued in a given tFAW (MIN) period. tRRD (MIN) restriction still applies.
The minimum internal READ-to-PRECHARGE time. This is the time from which the last 4-bit prefetch begins to
when the PRECHARGE command can be issued. A 4-bit prefetch is when the READ command internally latches the
READ so that data will output CL later. This parameter is only applicable when tRTP/(2 × tCK) > 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, 8192 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 121)).
tISXR is equal to tIS and is used for CKE setup time during self refresh exit, as shown in Figure 67 (page 112).
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.
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45. 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 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).
46. ODT turn-on time tAON (MIN) is when the device leaves High-Z and ODT resistance begins to turn on. ODT turnon time tAON (MAX) is when the ODT resistance is fully on. Both are measured from tAOND.
47. 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.
48. 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 tERR5per (MIN) and tJITdty (MIN).
49. The -187E maximum limit is 2 × tCK + tAC (MAX) + 1000 but it will likely be 3 x tCK + tAC (MAX) + 1000 in the
future.
50. Should use 8 tCK for backward compatibility.
51. DRAM devices should be evenly addressed when being accessed. Disproportionate accesses to a particular row address may result in reduction of the product lifetime.
38
256Mb: x4, x8, x16 DDR2 SDRAM
AC Timing Operating Specifications
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‹ 2003 Micron Technology, Inc. All rights reserved.
256Mb: x4, x8, x16 DDR2 SDRAM
AC and DC Operating Conditions
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
Supply voltage
VDD
1.7
1.8
1.9
V
1, 2
VDDL supply voltage
VDDL
1.7
1.8
1.9
V
2, 3
I/O supply voltage
VDDQ
1.7
1.8
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
I/O reference voltage
I/O termination voltage (system)
Notes:
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VDD and VDDQ must track each other. VDDQ must be ื VDD.
VSSQ = VSSL = VSS.
VDDQ tracks with VDD; VDDL tracks with VDD.
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 percent of the DC value. Peak-to-peak AC noise on VREF may not exceed ±2 percent
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.
1.
2.
3.
4.
39
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256Mb: x4, x8, x16 DDR2 SDRAM
ODT DC Electrical Characteristics
ODT DC Electrical Characteristics
Table 13: ODT DC Electrical Characteristics
All voltages are referenced to VSS
Parameter
Symbol
Min
Nom
Max
Units
Notes
RTT effective impedance value for 75˖ setting
EMR (A6, A2) = 0, 1
RTT1(EFF)
60
75
90
˖
1, 2
RTT effective impedance value for 150˖ setting
EMR (A6, A2) = 1, 0
RTT2(EFF)
120
150
180
˖
1, 2
RTT effective impedance value for 50˖ setting
EMR (A6, A2) = 1, 1
RTT3(EFF)
40
50
60
˖
1, 2
˂VM
–6
–
6
%
3
Deviation of VM with respect to VDDQ/2
Notes:
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 less 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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256Mb: x4, x8, x16 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
mV
mV
Input high (logic 1) voltage
VIH(DC)
VREF(DC) + 125
VDDQ1
Input low (logic 0) voltage
VIL(DC)
–300
VREF(DC) - 125
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
Units
VREF(DC) + 250
VDDQ1
mV
VREF(DC) + 200
1
mV
VDDQ
Input high (logic 1) voltage (-187E/-25E/-25/-3E/-3)
VIH(AC)
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 51).
Figure 11: Single-Ended Input Signal Levels
Note:
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1,150mV
VIH(AC)
1,025mV
VIH(DC)
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 41).
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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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
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.
Note:
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 21˖ for values of VOUT between VDDQ and VDDQ - 280mV.
2. For IOL(DC); VDDQ = 1.7V, VOUT = 280mV. VOUT/IOL must be less than 21˖ 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 VIH,min plus a noise margin and
VIL,max 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 21˖ 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
Nom
Max
See Output Driver Characteristics (page 46)
Pull-up and pull-down mismatch
Output slew rate
Notes:
Units
Notes
˖
1, 2
0
–
4
˖
1, 2, 3
1.5
–
5
V/ns
1, 4, 5, 6
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 = 1420mV; (VOUT - VDDQ)/IOH must be less than 23.4˖ 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 23.4˖ 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.
Figure 14: Output Slew Rate Load
VTT = VDDQ/2
Output
(VOUT)
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25ȍ
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)
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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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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)
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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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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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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:
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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 64).
3. See Input Slew Rate Derating (page 53).
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 56), Figure 25 (page 57), Figure 27 (page 62), and Figure 29
(page 63).
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 64).
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 65).
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 64).
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 65).
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.
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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 ˂tIS and ˂tIH derating
value, respectively. Example: tIS (total setup time) = tIS (base) + ˂tIS.
tIS,
the nominal slew rate for a rising signal, is defined as the slew rate between the last
crossing of V REF(DC) and the first crossing of V IH(AC)min. Setup nominal slew rate (tIS) for
a falling signal is defined as the slew rate between the last crossing of V REF(DC) and the
first crossing of V IL(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 56)).
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 56)).
tIH,
the nominal slew rate for a rising signal, is defined as the slew rate between the last
crossing of V IL(DC)max and the first crossing of V REF(DC). tIH, nominal slew rate for a falling signal, is defined as the slew rate between the last crossing of V IH(DC)min and the first
crossing of V REF(DC).
If the actual signal is always later than the nominal slew rate line between shaded “DC
to V REF(DC) region,” use the nominal slew rate for the derating value (Figure 24
(page 57)).
If the actual signal is earlier than the nominal slew rate line anywhere between shaded
“DC to V REF(DC) region,” the slew rate of a tangent line to the actual signal from the DC
level to V REF(DC) level is used for the derating value (Figure 25 (page 57)).
Although the total setup time might be negative for slow slew rates (a valid input signal
will not have reached V IH[AC]/VIL[AC] at the time of the rising clock transition), a valid input signal is still required to complete the transition and reach V IH(AC)/VIL(AC).
For slew rates in between the values listed in Table 28 (page 54) and Table 29
(page 55), the derating values may obtained by linear interpolation.
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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)
˂tIS
˂tIH
˂tIS
˂tIH
˂tIS
˂tIH
Units
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
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0.2
–525
–500
–495
–470
–465
–440
ps
0.15
–800
–708
–770
–678
–740
–648
ps
0.1
–1450
–1125
–1420
–1095
–1390
–1065
ps
54
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256Mb: x4, x8, x16 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
˂tIS
˂tIH
˂tIS
˂tIH
˂tIS
˂tIH
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
–1000
–1125
–970
–1095
–940
–1065
ps
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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
ǻTF
ǻTR
VREF(DC) - VIL(AC)max
Setup slew rate
=
falling signal
ǻTF
VIH(AC)min - VREF(DC)
Setup slew rate
=
rising signal
ǻTR
Figure 23: Tangent Line for tIS
CK
CK#
tIH
tIS
VDDQ
tIS
tIH
VIH(AC)min
VREF to AC
region
Nominal
line
VIH(DC)min
Tangent
line
VREF(DC)
Tangent
line
VIL(DC)max
Nominal
line
VREF to AC
region
VIL(AC)max
ǻTF
ǻTR
VSS
Tangent line (VIH[AC]min - VREF[DC])
Setup slew rate
=
rising signal
ǻTR
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256Mb: x4, x8, x16 DDR2 SDRAM
Input Slew Rate Derating
Figure 24: Nominal Slew Rate for tIH
CK
CK#
tIS
tIS
tIH
tIH
VDDQ
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
ǻTF
ǻTR
Figure 25: Tangent Line for tIH
CK
CK#
tIS
tIS
tIH
tIH
VDDQ
VIH(AC)min
Nominal
line
VIH(DC)min
DC to VREF
region
Tangent
line
VREF(DC)
Tangent
line
Nominal
line
DC to VREF
region
VIL(DC)max
VIL(AC)max
VSS
ǻTR
Tangent line (VREF[DC] - VIL[DC]max)
Hold slew rate
=
rising signal
ǻTR
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57
ǻTF
Hold slew rate Tangent line (VIH[DC]min - VREF[DC])
=
falling signal
ǻTF
Micron Technology, Inc. reserves the right to change products or specifications without notice.
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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
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
tDS
tDH
2.0
125
45
125
45
125
45
–
–
–
–
–
–
–
–
–
–
–
–
1.5
83
21
83
21
83
21
95
33
–
–
–
–
–
–
–
–
–
–
1.0
0
0
0
0
0
0
12
12
24
24
–
–
–
–
–
–
–
–
0.9
–
–
–11
–14
–11
–14
1
–2
13
10
25
22
–
–
–
–
–
–
0.8
–
–
–
–
–25
–31
–13
–19
–1
–7
11
5
23
17
–
–
–
–
0.7
–
–
–
–
–
–
–31
–42
–19
–30
–7
–18
5
–6
17
6
–
–
0.6
–
–
–
–
–
–
–
–
–43
–59
–31
–47
–19
–35
–7
–23
5
–11
0.5
–
–
–
–
–
–
–
–
–
–
–74
–89
–62
–77
–50
–65
–38
–53
0.4
–
–
–
–
–
–
–
–
–
–
–
–
4.0 V/ns
3.0 V/ns
Notes:
PDF: 09005aef8117c187
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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
–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 62)). 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 62)).
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 63)). 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 63)).
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 60) 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 61) and
Table 35 (page 61). 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.
58
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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
2.4 V/ns
2.0 V/ns
1.8 V/ns
1.6 V/ns
1.4 V/ns
1.2 V/ns
1.0 V/ns
0.8 V/ns
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: 09005aef8117c187
256MbDDR2.pdf - Rev. N 7/11 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 62)). 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 62)).
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 63)). 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 63)).
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 60) 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 60). Table 33 provides the VREF-based fully derated values for the DQ (tDSa and tDHa) for
59
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256Mb: x4, x8, x16 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
DQ (V/ns)
tDS
1.8 V/ns
tDH
tDS
1.6 V/ns
tDH
tDS
1.4 V/ns
tDH
tDS
1.2 V/ns
tDH
tDS
tDH
1.0 V/ns
tDS
tDH
0.8 V/ns
tDS
tDH
0.6 V/ns
tDS
tDH
0.4 V/ns
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
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
0.7
391
290
391
290
391
290
391
290
391
290
0.6
426
290
426
290
426
290
426
290
426
290
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
285
392
282
402
278
412
275
406
285
416
281
426
278
436
275
441
285
451
282
461
278
471
275
0.5
472
290
472
290
472
290
472
290
472
290
487
285
497
282
507
278
517
275
0.4
522
289
522
289
522
289
522
289
522
289
537
284
547
281
557
278
567
274
PDF: 09005aef8117c187
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60
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‹ 2003 Micron Technology, Inc. All rights reserved.
256Mb: x4, x8, x16 DDR2 SDRAM
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
tDH
VDDQ
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
ǻTF
ǻTR
VREF(DC) - VIL(AC)max
Setup slew rate
=
falling signal
Note:
VIH(AC)min - VREF(DC)
Setup slew rate
=
rising signal
ǻTR
ǻTF
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
DS
DH
t
DH
VIH(AC)min
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
ǻTR
ǻTF
VSS
Setup slew rate
=
falling signal
Note:
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Tangent line (V REF[DC] - VIL[AC]max)
ǻTF
Tangent line (VIH[AC]min - VREF[DC])
Setup slew rate
=
rising signal
ǻTR
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
tIS
tIH
tIH
VDDQ
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
ǻTF
ǻTR
Hold slew rate VIH(DC)min - VREF(DC)
=
falling signal
ǻTF
Hold slew rate VREF(DC) - VIL(DC)max
=
rising signal
ǻTR
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
tIS
tIH
tIH
VDDQ
VIH(AC)min
Nominal
line
VIH(DC)min
DC to VREF
region
Tangent
line
VREF(DC)
Tangent
line
Nominal
line
DC to VREF
region
VIL(DC)max
VIL(AC)max
VSS
Hold slew rate
=
rising signal
Note:
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Tangent line (VREF[DC] - VIL[DC]max)
ǻTR
ǻTF
ǻTR
Hold slew rate Tangent line (VIH[DC]min - VREF[DC])
=
falling signal
ǻTF
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
64
tDS
a
tDH
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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
Vswing (MAX)
VIH(AC)min
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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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 123) 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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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 92) and Figure 59 (page 103) for other restrictions and details.
9. The power-down mode does not perform any REFRESH operations. The duration of
power-down 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
Idle
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)
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
Row active
Notes:
8
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.
Row
A row in the bank has been activated, and tRCD has been met. No data bursts/
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.
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 69).
Idle:
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Commands
Precharge:
Starts with registration of a PRECHARGE command and ends when
is met. After tRP is met, the bank will be in the idle state.
Read with auto Starts with registration of a READ command with auto precharge
precharge
enabled and ends when tRP has been met. After tRP is met, the
enabled:
bank will be in the idle state.
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 auto Starts with registration of a WRITE command with auto precharge
precharge
enabled and ends when tRP has been met. After tRP is met, the
enabled:
bank will be in the idle state.
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):
tRP
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.
Accessing
Starts with registration of the LOAD MODE command and ends when
tMRD has been met. After tMRD is met, the DDR2 SDRAM will be in the
mode
register:
all banks idle state.
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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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 70).
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 72). 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 108)).
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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 73). 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 8bit 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 73). 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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256Mb: x4, x8, x16 DDR2 SDRAM
Mode Register (MR)
Write Recovery
Write recovery (WR) time is defined by bits M9–M11, as shown in Figure 34 (page 73).
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 107).
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 I DD3P 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 73). 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 79).
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
T0
T1
T2
T3
T4
T5
T6
READ
NOP
NOP
NOP
NOP
NOP
NOP
CK#
CK
Command
DQS, DQS#
DO
n
DQ
DO
n+1
DO
n+2
DO
n+3
CL = 3 (AL = 0)
T0
T1
T2
T3
T4
T5
T6
READ
NOP
NOP
NOP
NOP
NOP
NOP
CK#
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
75Ÿ
1 0
150Ÿ
E1
1 1
50Ÿ
0
Full
1
Reduced
0
No
1
Yes
E10 DQS# Enable
E15 E14
Output Drive Strength
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
E9 E8 E7 OCD Operation
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Address bus
E12
E11 RDQS Enable
Notes:
A1 A0
4
0
0
0
OCD exit
0
0
1
Reserved
0
1
0
Reserved
1
0
0
Reserved
1
1
1
Enable OCD defaults
3
Mode Register Set
0
0
0
1
Extended mode register (EMR)
1
0
Extended mode register (EMR2)
1
1
Extended mode register (EMR3)
Mode register (MR)
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 83) 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 77). 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 20˖ to 10k˖ 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 77). 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 50˖˖, and 150˖ 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 150˖ each, enabling an effective resistance of 75˖(RTT2 [EFF] = R2/2). Similarly, if “sw2” is enabled, all
R2 values that are 300˖ each, enable an effective ODT resistance of 150˖
(RTT2[EFF] = R2/2). Switch “sw3” enables R1 values of 100˖, enabling effective resistance
of 50˖. 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 124) 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 83) 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 80). An example of a WL is shown in Figure 38 (page 80).
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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)
DO
n
DQ
AL = 2
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
T0
T1
ACTIVE n
WRITE n
CK#
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 T C 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
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12 11
0 0
10 9 8 7 6
0 0 SRT 0
0
5 4 3 2
0 0 0 0
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)
E15 E14
Notes:
15 14 n
MRS 0
A1 A0
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
0
MRS
E15 E14
Notes:
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0
12 11
10
0
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
0
1
Extended mode register (EMR)
1
0
Extended mode register (EMR2)
1
1
Extended mode register (EMR3)
Mode register (MR)
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
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
CK#
CK
tCL
LVCMOS
CKE low level2
tCL
SSTL_18 2
low level
ODT
83
Command
15
DM
15
DQS
High-Z
15
DQ
High-Z
Rtt
High-Z
T = 200μs (MIN)3
Power-up:
VDD and stable
clock (CK, CK#)
T = 400ns (MIN)4
tRPA
tMRD
tMRD
EMR(2)
EMR(3)
tMRD
tMRD
tRPA
tRFC
tRFC
tMRD
tMRD
tMRD
6HHQR WH
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
256Mb: x4, x8, x16 DDR2 SDRAM
Initialization
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16
Address
256Mb: x4, x8, x16 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 Table 12 (page 39)):
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), Table 12 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, Table 12 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 81) 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 77) 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 72) for all MR requirements.
Issue PRECHARGE ALL command.
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256Mb: x4, x8, x16 DDR2 SDRAM
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 72) 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 77) 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 DQ[3:0] for x4, DQ[7:0] for x8 and
DQ[15:0] for x16.
16. A10 = PRECHARGE ALL, CODE = desired values for mode registers (bank addresses are
required to be decoded).
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256Mb: x4, x8, x16 DDR2 SDRAM
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 87).
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256Mb: x4, x8, x16 DDR2 SDRAM
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
Bank b
tRRD (MIN)
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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256Mb: x4, x8, x16 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 89) 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 97) and Figure 54 (page 98). A detailed explanation of tDQSCK (DQS transition skew to CK) and
tAC (data-out transition skew to CK) is shown in Figure 55 (page 99).
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 90)).
Nonconsecutive read data is illustrated in Figure 46 (page 91). 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 94)).
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 92), 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 92). The tDQSS (NOM) case is shown (tDQSS [MIN] and tDQSS [MAX] are defined in Figure 56 (page 101)).
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256Mb: x4, x8, x16 DDR2 SDRAM
READ
Figure 44: READ Latency
T0
T1
T2
T3
READ
NOP
NOP
NOP
T3n
T4
T4n
T5
CK#
CK
Command
Address
NOP
NOP
Bank a,
Col n
RL = 3 (AL = 0, CL = 3)
DQS, DQS#
DO
n
DQ
T0
T1
T2
T3
T4
T4n
READ
NOP
NOP
NOP
NOP
T5
T5n
CK#
CK
Command
Address
NOP
Bank a,
Col n
AL = 1
CL = 3
RL = 4 (AL = 1 + CL = 3)
DQS, DQS#
DO
n
DQ
T0
T1
T2
T3
READ
NOP
NOP
NOP
T3n
T4
T4n
T5
CK#
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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256Mb: x4, x8, x16 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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256Mb: x4, x8, x16 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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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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256Mb: x4, x8, x16 DDR2 SDRAM
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
DO
n+1
DO
n+2
DO
n+3
DI
n
DI
n+1
DI
n+2
DI
n+3
CL = 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. Fol-
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256Mb: x4, x8, x16 DDR2 SDRAM
READ
lowing the PRECHARGE command, a subsequent command to the same bank cannot
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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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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256Mb: x4, x8, x16 DDR2 SDRAM
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 95) and Figure 52 (page 96),
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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256Mb: x4, x8, x16 DDR2 SDRAM
READ
Figure 51: Bank Read – Without Auto Precharge
CK#
T1
T0
T2
T3
T4
NOP1
READ2
T5
T6
T7
T7n
NOP1
PRE3
NOP1
T8
T8n
T9
CK
tCH
tCK
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
tDQSCK (MIN)
Case 1: tAC (MIN) and tDQSCK (MIN)
7
tRPRE
tRPST
7
DQS, DQS#
tLZ (MIN)
DO
n
DQ8
tLZ (MIN)
Case 2: tAC (MAX) and tDQSCK (MAX)
7
tRPRE
tAC (MIN)
tDQSCK (MAX)
tHZ (MIN)
tRPST
7
DQS, DQS#
tLZ (MAX)
DQ8
DO
n
tLZ (MIN)
tAC (MAX)
Transitioning Data
Notes:
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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.
95
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256Mb: x4, x8, x16 DDR2 SDRAM
READ
Figure 52: Bank Read – with Auto Precharge
CK#
T1
T0
T2
T3
T4
T5
T6
T7
T7n
READ2,3
NOP1
NOP1
NOP1
NOP1
T8
T8n
CK
tCK
tCH
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
tRCD
tRTP
tRP
tRAS
tRC
DM
tDQSCK (MIN)
Case 1: tAC (MIN) and tDQSCK (MIN)
5
tRPRE
tRPST
5
DQS, DQS#
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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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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256Mb: x4, x8, x16 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 DQ[7:0] 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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256Mb: x4, x8, x16 DDR2 SDRAM
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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256Mb: x4, x8, x16 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
T01
T1
T2
T3
T3n
T4
T4n
T5
T5n
T6
T6n
T7
CK#
CK
tLZ (MIN)
tDQSCK2 (MAX)
tDQSCK2 (MIN)
tHZ (MAX)
tRPST
tRPRE
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)
T5n
T6
T6n
T5
T5n
T6
T6n
T5
T5n
T6
T6n
T5
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 71)). 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
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256Mb: x4, x8, x16 DDR2 SDRAM
WRITE
±tDQSS. tDQSS is specified with a relatively wide range (25% of one clock cycle). All of
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 101) 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 102) 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 102). 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 103).
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 104). 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 105). 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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256Mb: x4, x8, x16 DDR2 SDRAM
WRITE
Figure 56: Write Burst
T0
T1
T2
Command
WRITE
NOP
NOP
Address
Bank a,
Col b
T2n
T3
T3n
T4
CK#
CK
t DQSS (NOM)
NOP
WL ± tDQSS
NOP
5
DQS, DQS#
DI
b
DQ
DM
t DQSS (MIN)
tDQSS5
WL - tDQSS
DQS, DQS#
DI
b
DQ
DM
t DQSS (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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256Mb: x4, x8, x16 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
WL = 2
Address
tDQSS (NOM)
NOP
NOP
NOP
1
1
WL = 2
Bank,
Col b
Bank,
Col n
WL ± tDQSS
1
DQS, DQS#
DQ
DI
b
DI
n
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 (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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256Mb: x4, x8, x16 DDR2 SDRAM
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:
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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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256Mb: x4, x8, x16 DDR2 SDRAM
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
t DQSS (NOM)
Bank a,
Col n
WL ± tDQSS
CL = 3
2
DQS, DQS#
DI
b
DQ
DI
DM
t DQSS (MIN)
WL - tDQSS
CL = 3
2
DQS, DQS#
DI
b
DQ
DI
DM
t DQSS (MAX)
WL + tDQSS
CL = 3
2
DQS, DQS#
DI
b
DQ
DI
DM
Transitioning Data
Notes:
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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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256Mb: x4, x8, x16 DDR2 SDRAM
WRITE
Figure 61: WRITE-to-PRECHARGE
T0
T1
T2
WRITE
NOP
NOP
T2n
T3
T3n
T4
T5
NOP
NOP
T6
T7
NOP
PRE
CK#
CK
Command
NOP
tWR
Address
Bank a,
Col b
t DQSS (NOM)
tRP
Bank,
(a or all)
WL + tDQSS
1
DQS#
DQS
DI
b
DQ
DM
t DQSS (MIN)
WL - tDQSS
1
DQS#
DQS
DI
b
DQ
DM
t DQSS (MAX)
WL + tDQSS
1
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. 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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256Mb: x4, x8, x16 DDR2 SDRAM
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:
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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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256Mb: x4, x8, x16 DDR2 SDRAM
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:
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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.
t
7. DSH 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.
107
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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
NOP1
NOP1
NOP1
NOP1
PRE
All banks
One bank
Bank select
Bank x
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:
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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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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)
t DSH 1 t DSS 2
DQS
DQS#
t WPRE
DQ
t DQSL
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 exceeds
C
85°C.
Figure 66: Refresh Mode
T0
T2
T1
T3
T4
Ta0
Ta1
Tb0
Tb1
Tb2
NOP1
REF
NOP1
REF2
NOP1
NOP1
ACT
CK#
CK
tCK
tCH
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:
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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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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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SELF REFRESH
Figure 67: Self Refresh
T0
T1
T2
Ta0
Ta1
Tb0
Ta2
Tc0
Td0
CK#
CK1
tCH
tCK1
tCL
tCK1
tISXR2
W ,+
tCKE3
CKE1
Command
NOP
NOP4
REF
NOP4
Valid 5
Valid5
W ,+
ODT6
tAOFD/tAOFPD6
Address
Valid
Valid7
DQS#, DQS
DQ
DM
tXSNR2, 5, 10
tCKE (MIN)9
tRP8
tXSRD2, 7
Enter self refresh
mode (synchronous)
Notes:
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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 114). Detailed
power-down entry conditions are shown in Figure 69 (page 116)–Figure 76 (page 119).
Table 43 (page 115) 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 117) and Figure 72
(page 117) on Figure 72 (page 117). 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 114)) 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 120)).
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 125)–Figure 86 (page 129).
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 114).
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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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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
power-down.
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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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
7, 8, 11, 12
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 66)
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 123) 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 111) and SELF REFRESH (page 72) 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 66).
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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
RL = 3
DO
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:
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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:
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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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Power-Down Mode
Figure 73: REFRESH Command-to-Power-Down Entry
T0
T1
T2
Valid
REFRESH
NOP
T3
CK#
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
T0
T1
T2
Valid
ACT
NOP
T3
CK#
CK
Command
Address
VALID
tCKE (MIN)
CKE
1 tCK
Power-down1
entry
Don’t Care
Note:
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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:
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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 powerdown 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
Previous clock frequency
T0
T1
T2
New clock frequency
T3
Ta1
Ta0
Ta2
Ta3
Ta4
Tb0
NOP
Valid
CK#
CK
tCH
tCH
tCL
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:
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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, V DDQ, V DDL, 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 122) shows the proper sequence for a RESET operation.
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256Mb: x4, x8, x16 DDR2 SDRAM
Reset
Figure 78: RESET Function
T0
T1
T2
T3
T4
T5
tCK
Tb0
Ta0
CK#
CK
tCL
tDELAY
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 b
Bank a
DQS3
DQ3
High-Z
High-Z
High-Z
DO
DO
High-Z
DO
High-Z
RTT
System
RESET
T = 400ns (MIN)
tRPA
Start of normal5
initialization
sequence
Indicates a break in
time scale
Notes:
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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 83).
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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 124).
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 125).
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 126).
ODT turn-off timing, prior to entering any power-down mode, is determined by the parameter tANPD (MIN), as shown in Figure 83 (page 126). 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 126) 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 127). 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 127) 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 128). 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 128) 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 power-down mode is determined by the parameter tAXPD (MIN), as shown in Figure 86
(page 129). At state Ta1, the ODT HIGH signal satisfies tAXPD (MIN) after exiting power-down mode at state T1. When tAXPD (MIN) is satisfied, tAOND and tAON timing parameters apply. Figure 86 (page 129) 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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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
tAONPD/tAOFPD
(synchronous)
tAOND/tAOFD
(asynchronous)
Applicable timing parameters
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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
T1
T2
T3
T4
T5
T6
CK
tCK
tCH
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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RTT On
Don’t Care
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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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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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RTT Unknown
RTT On
Don’t Care
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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
128
RTT On
Transitioning RTT
Don’t Care
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256Mb: x4, x8, x16 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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