W9725G6KB
4M 4 BANKS 16 BIT DDR2 SDRAM
Publication Release Date: Feb. 07, 2017
Revision: A04
- 1 -
Table of Contents-
1. GENERAL DESCRIPTION ................................................................................................................... 4
2. FEATURES ........................................................................................................................................... 4
3. ORDER INFORMATION ....................................................................................................................... 5
4. KEY PARAMETERS ............................................................................................................................. 5
5. BALL CONFIGURATION ...................................................................................................................... 6
6. BALL DESCRIPTION ............................................................................................................................ 7
7. BLOCK DIAGRAM ................................................................................................................................ 8
8. FUNCTIONAL DESCRIPTION .............................................................................................................. 9
8.1 Power-up and Initialization Sequence ................................................................................................... 9
8.2 Mode Register and Extended Mode Registers Operation ................................................................... 10
8.2.1 Mode Register Set Command (MRS)............................................................................... 10
8.2.2 Extend Mode Register Set Commands (EMRS) .............................................................. 11
8.2.2.1 Extend Mode Register Set Command (1), EMR (1) ................................................ 11
8.2.2.2 DLL Enable/Disable ................................................................................................ 12
8.2.2.3 Extend Mode Register Set Command (2), EMR (2) ................................................ 13
8.2.2.4 Extend Mode Register Set Command (3), EMR (3) ................................................ 14
8.2.3 Off-Chip Driver (OCD) Impedance Adjustment ................................................................ 15
8.2.3.1 Extended Mode Register for OCD Impedance Adjustment .................................... 16
8.2.3.2 OCD Impedance Adjust .......................................................................................... 16
8.2.3.3 Drive Mode ............................................................................................................. 17
8.2.4 On-Die Termination (ODT) ............................................................................................... 18
8.2.5 ODT related timings ......................................................................................................... 18
8.2.5.1 MRS command to ODT update delay ..................................................................... 18
8.3 Command Function ............................................................................................................................. 20
8.3.1 Bank Activate Command .................................................................................................. 20
8.3.2 Read Command ............................................................................................................... 20
8.3.3 Write Command ............................................................................................................... 21
8.3.4 Burst Read with Auto-precharge Command ..................................................................... 21
8.3.5 Burst Write with Auto-precharge Command ..................................................................... 21
8.3.6 Precharge All Command .................................................................................................. 21
8.3.7 Self Refresh Entry Command .......................................................................................... 21
8.3.8 Self Refresh Exit Command ............................................................................................. 22
8.3.9 Refresh Command ........................................................................................................... 22
8.3.10 No-Operation Command .................................................................................................. 23
8.3.11 Device Deselect Command .............................................................................................. 23
8.4 Read and Write access modes ........................................................................................................... 23
8.4.1 Posted
CAS
................................................................................................................... 23
8.4.1.1 Examples of posted
CAS
operation ..................................................................... 23
8.4.2 Burst mode operation ....................................................................................................... 24
8.4.3 Burst read mode operation ............................................................................................... 25
8.4.4 Burst write mode operation .............................................................................................. 25
8.4.5 Write data mask ............................................................................................................... 26
8.5 Burst Interrupt ..................................................................................................................................... 26
8.6 Precharge operation ............................................................................................................................ 27
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 2 -
8.6.1 Burst read operation followed by precharge ..................................................................... 27
8.6.2 Burst write operation followed by precharge .................................................................... 27
8.7 Auto-precharge operation ................................................................................................................... 27
8.7.1 Burst read with Auto-precharge ....................................................................................... 28
8.7.2 Burst write with Auto-precharge ....................................................................................... 28
8.8 Refresh Operation ............................................................................................................................... 29
8.9 Power Down Mode .............................................................................................................................. 29
8.9.1 Power Down Entry ........................................................................................................... 30
8.9.2 Power Down Exit .............................................................................................................. 30
8.10 Input clock frequency change during precharge power down ............................................................. 30
9. OPERATION MODE ........................................................................................................................... 31
9.1 Command Truth Table ........................................................................................................................ 31
9.2 Clock Enable (CKE) Truth Table for Synchronous Transitions ........................................................... 32
9.3 Data Mask (DM) Truth Table ............................................................................................................... 32
9.4 Function Truth Table ........................................................................................................................... 33
9.5 Simplified Stated Diagram ................................................................................................................... 36
10. ELECTRICAL CHARACTERISTICS ................................................................................................... 37
10.1 Absolute Maximum Ratings ................................................................................................................ 37
10.2 Operating Temperature Condition ....................................................................................................... 37
10.3 Recommended DC Operating Conditions ........................................................................................... 37
10.4 ODT DC Electrical Characteristics ...................................................................................................... 38
10.5 Input DC Logic Level ........................................................................................................................... 38
10.6 Input AC Logic Level ........................................................................................................................... 38
10.7 Capacitance ........................................................................................................................................ 39
10.8 Leakage and Output Buffer Characteristics ........................................................................................ 39
10.9 DC Characteristics .............................................................................................................................. 40
10.10 IDD Measurement Test Parameters .......................................................................................... 42
10.11 AC Characteristics ..................................................................................................................... 43
10.11.1 AC Characteristics and Operating Condition for -18 speed grade ................................... 43
10.11.2 AC Characteristics and Operating Condition for -25/25I/-3 speed grade ......................... 45
10.12 AC Input Test Conditions ........................................................................................................... 66
10.13 Differential Input/Output AC Logic Levels .................................................................................. 66
10.14 AC Overshoot / Undershoot Specification ................................................................................. 67
10.14.1 AC Overshoot / Undershoot Specification for Address and Control Pins: ........................ 67
10.14.2 AC Overshoot / Undershoot Specification for Clock, Data, Strobe and Mask pins: .......... 67
11. TIMING WAVEFORMS ....................................................................................................................... 68
11.1 Command Input Timing ....................................................................................................................... 68
11.2 ODT Timing for Active/Standby Mode ................................................................................................. 69
11.3 ODT Timing for Power Down Mode .................................................................................................... 69
11.4 ODT Timing mode switch at entering power down mode .................................................................... 70
11.5 ODT Timing mode switch at exiting power down mode ...................................................................... 71
11.6 Data output (read) timing .................................................................................................................... 72
11.7 Burst read operation: RL=5 (AL=2, CL=3, BL=4) ................................................................................ 72
11.8 Data input (write) timing ...................................................................................................................... 73
11.9 Burst write operation: RL=5 (AL=2, CL=3, WL=4, BL=4) .................................................................... 73
11.10 Seamless burst read operation: RL = 5 ( AL = 2, and CL = 3, BL = 4) ...................................... 74
11.11 Seamless burst write operation: RL = 5 ( WL = 4, BL = 4) ......................................................... 74
11.12 Burst read interrupt timing: RL =3 (CL=3, AL=0, BL=8) ............................................................. 75
11.13 Burst write interrupt timing: RL=3 (CL=3, AL=0, WL=2, BL=8) .................................................. 75
11.14 Write operation with Data Mask: WL=3, AL=0, BL=4) ............................................................... 76
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
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11.15 Burst read operation followed by precharge: RL=4 (AL=1, CL=3, BL=4, tRTP ≤ 2clks) ............ 77
11.16 Burst read operation followed by precharge: RL=4 (AL=1, CL=3, BL=8, tRTP ≤ 2clks) ............ 77
11.17 Burst read operation followed by precharge: RL=5 (AL=2, CL=3, BL=4, tRTP ≤ 2clks) ............ 78
11.18 Burst read operation followed by precharge: RL=6 (AL=2, CL=4, BL=4, tRTP ≤ 2clks) ............ 78
11.19 Burst read operation followed by precharge: RL=4 (AL=0, CL=4, BL=8, tRTP > 2clks) ............ 79
11.20 Burst write operation followed by precharge: WL = (RL-1) = 3 .................................................. 79
11.21 Burst write operation followed by precharge: WL = (RL-1) = 4 .................................................. 80
11.22 Burst read operation with Auto-precharge: RL=4 (AL=1, CL=3, BL=8, tRTP ≤ 2clks) ............... 80
11.23 Burst read operation with Auto-precharge: RL=4 (AL=1, CL=3, BL=4, tRTP > 2clks) ............... 81
11.24 Burst read with Auto-precharge followed by an activation to the same bank (tRC Limit): RL=5
(AL=2, CL=3, internal tRCD=3, BL=4, tRTP ≤ 2clks) ....................................................................................... 81
11.25 Burst read with Auto-precharge followed by an activation to the same bank (tRP Limit): RL=5
(AL=2, CL=3, internal tRCD=3, BL=4, tRTP ≤ 2clks) ....................................................................................... 82
11.26 Burst write with Auto-precharge (tRC Limit): WL=2, WR=2, BL=4, tRP=3 ................................. 82
11.27 Burst write with Auto-precharge (WR + tRP Limit): WL=4, WR=2, BL=4, tRP=3 ....................... 83
11.28 Self Refresh Timing ................................................................................................................... 83
11.29 Basic Power Down Entry and Exit Timing.................................................................................. 84
11.30 Precharged Power Down Entry and Exit Timing ........................................................................ 84
11.31 Clock frequency change in precharge Power Down mode ........................................................ 85
12. PACKAGE SPECIFICATION .............................................................................................................. 86
13. REVISION HISTORY .......................................................................................................................... 87
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 4 -
1. GENERAL DESCRIPTION
The W9725G6KB is a 256M bits DDR2 SDRAM, organized as 4,194,304 words 4 banks 16 bits.
This device achieves high speed transfer rates up to 1066Mb/sec/pin (DDR2-1066) for general
applications. W9725G6KB is sorted into the following speed grades: -18, -25, 25I and -3. The -18
grade parts is compliant to the DDR2-1066 (7-7-7) specification. The -25 and 25I grade parts are
compliant to the DDR2-800 (5-5-5) or DDR2-800 (6-6-6) specification (the 25I industrial grade parts
which is guaranteed to support -40°C ≤ TCASE ≤ 95°C). The -3 grade parts is compliant to the DDR2-
667 (5-5-5) specification.
All of the control and address inputs are synchronized with a pair of externally supplied differential
clocks. Inputs are latched at the cross point of differential clocks (CLK rising and
CLK
falling). All
I/Os are synchronized with a single ended DQS or differential DQS-
DQS
pair in a source
synchronous fashion.
2. FEATURES
Power Supply: VDD, VDDQ = 1.8 V ± 0.1V
Double Data Rate architecture: two data transfers per clock cycle
CAS Latency: 3, 4, 5, 6 and 7
Burst Length: 4 and 8
Bi-directional, differential data strobes (DQS and
DQS
) are transmitted / received with data
Edge-aligned with Read data and center-aligned with Write data
DLL aligns DQ and DQS transitions with clock
Differential clock inputs (CLK and
CLK
)
Data masks (DM) for write data
Commands entered on each positive CLK edge, data and data mask are referenced to both edges
of DQS
Posted
CAS
programmable additive latency supported to make command and data bus efficiency
Read Latency = Additive Latency plus CAS Latency (RL = AL + CL)
Off-Chip-Driver impedance adjustment (OCD) and On-Die-Termination (ODT) for better signal
quality
Auto-precharge operation for read and write bursts
Auto Refresh and Self Refresh modes
Precharged Power Down and Active Power Down
Write Data Mask
Write Latency = Read Latency - 1 (WL = RL - 1)
Interface: SSTL_18
Packaged in WBGA 84 Ball (8x12.5 mm2), using Lead free materials with RoHS compliant
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 5 -
3. ORDER INFORMATION
PART NUMBER
SPEED GRADE
OPERATING TEMPERATURE
W9725G6KB-18
DDR2-1066 (7-7-7)
0°C ≤ TCASE ≤ 85°C
W9725G6KB-25
DDR2-800 (5-5-5) or DDR2-800 (6-6-6)
0°C ≤ TCASE ≤ 85°C
W9725G6KB25I
DDR2-800 (5-5-5) or DDR2-800 (6-6-6)
-40°C ≤ TCASE ≤ 95°C
W9725G6KB-3
DDR2-667 (5-5-5)
0°C ≤ TCASE ≤ 85°C
4. KEY PARAMETERS
SYM.
SPEED GRADE
DDR2-1066
DDR2-800
DDR2-667
Bin(CL-tRCD-tRP)
7-7-7
5-5-5/6-6-6
5-5-5
Part Number Extension
-18
-25/25I
-3
tCK(avg)
Average clock period
@CL = 7
Min.
1.875 nS
Max.
7.5 nS
@CL = 6
Min.
2.5 nS
2.5 nS
Max.
7.5 nS
8 nS
@CL = 5
Min.
3 nS
2.5 nS
3 nS
Max.
7.5 nS
8 nS
8 nS
@CL = 4
Min.
3.75 nS
3.75 nS
3.75 nS
Max.
7.5 nS
8 nS
8 nS
@CL = 3
Min.
5 nS
5 nS
Max.
8 nS
8 nS
tRCD
Active to Read/Write Command Delay Time
Min.
13.125 nS
12.5 nS
15 nS
tRP
Precharge to Active Command Period
Min.
13.125 nS
12.5 nS
15 nS
tRC
Active to Ref/Active Command Period
Min.
58.125 nS
57.5 nS
60 nS
tRAS
Active to Precharge Command Period
Min.
45 nS
45 nS
45 nS
IDD0
Operating current
Max.
70 mA
60 mA
55 mA
IDD1
Operation current (Single bank)
Max.
80 mA
70 mA
65 mA
IDD4R
Operating burst read current
Max.
125 mA
105 mA
95 mA
IDD4W
Operating burst write current
Max.
130 mA
110 mA
100 mA
IDD5B
Burst refresh current
Max.
75 mA
70 mA
65 mA
IDD6
Self refresh current (TCASE ≤ 85°C)
Max.
6 mA
6 mA
6 mA
IDD7
Operating bank interleave read current
Max.
160 mA
135 mA
115 mA
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 6 -
5. BALL CONFIGURATION
1 2 3 4 5 6 7 8 9
A
B
C
D
E
F
G
H
J
K
L
VSSQ
UDQS
VDDQ
LDQS
VDDQ
CAS
A2
A6
UDQS
VSSQ
DQ8
VSSQ
DQ0
CLK
A0
A4
CLK
CS
VDDQ
VDDQ
DQ7
VDD
ODT
VDD
DQ14
VDDQ
DQ12
NC
VDDL
NC
VSSQ
DQ9
VSSQ
A3
CKE
BA0BA1
WE
DQ3
LDM
VSS
DQ11
VDDQ
VSS
UDM
VDD
DQ6
VDDQ
DQ4
VSS
VDD A12 NC NCNC
A11 A8A9A7
A5
A1
A10/AP
VSSVREF
DQ1
VSSQ
VDDQ
VSSQ
NC VSSQ LDQS
VSSQDQ10
DQ15
DQ13
VDDQ
VDDQ
DQ5
VDD
VSS
M
N
P
R
VSSQDQ2
VSSDL
RAS
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 7 -
6. BALL DESCRIPTION
BALL NUMBER
SYMBOL
FUNCTION
DESCRIPTION
M8,M3,M7,N2,N8,N3
,N7,P2,P8,P3,M2,P7
,R2
A0−A12
Address
Provide the row address for active commands, and the column address
and Auto-precharge bit for Read/Write commands to select one
location out of the memory array in the respective bank.
Row address: A0−A12.
Column address: A0−A8. (A10 is used for Auto-precharge)
L2,L3
BA0−BA1
Bank Select
BA0−BA1 define to which bank an ACTIVE, READ, WRITE or
PRECHARGE command is being applied.
G8,G2,H7,H3,H1,H9
,F1,F9,C8,C2,D7,D3,
D1,D9,B1,B9
DQ0−DQ15
Data Input
/ Output
Bi-directional data bus.
K9
ODT
On Die
Termination
Control
ODT (registered HIGH) enables termination resistance internal to the
DDR2 SDRAM.
F7,E8
LDQS,
LDQS
LOW Data Strobe
Data Strobe for Lower Byte: Output with read data, input with write data
for source synchronous operation. Edge-aligned with read data, center-
aligned with write data. LDQS corresponds to the data on DQ0−DQ7.
LDQS
is only used when differential data strobe mode is enabled via
the control bit at EMR (1)[A10 EMRS command].
B7,A8
UDQS,
UDQS
UP Data Strobe
Data Strobe for Upper Byte: Output with read data, input with write data
for source synchronous operation. Edge-aligned with read data, center-
aligned with write data. UDQS corresponds to the data on DQ8−DQ15.
UDQS
is only used when differential data strobe mode is enabled via
the control bit at EMR (1)[A10 EMRS command].
L8
CS
Chip Select
All commands are masked when
CS
is registered HIGH.
CS
provides for external rank selection on systems with multiple ranks.
CS
is considered part of the command code.
K7,L7,K3
RAS
,
CAS
,
WE
Command Inputs
RAS
,
CAS
and
WE
(along with
CS
) define the command being
entered.
B3,F3
UDM, LDM
Input Data Mask
DM is an input mask signal for write data. Input data is masked when
DM is sampled high coincident with that input data during a Write
access. DM is sampled on both edges of DQS. Although DM pins are
input only, the DM loading matches the DQ and DQS loading.
J8,K8
CLK,
CLK
Differential Clock
Inputs
CLK and
CLK
are differential clock inputs. All address and control
input signals are sampled on the crossing of the positive edge of CLK
and negative edge of
CLK
. Output (read) data is referenced to the
crossings of CLK and
CLK
(both directions of crossing).
K2
CKE
Clock Enable
CKE (registered HIGH) activates and CKE (registered LOW)
deactivates clocking circuitry on the DDR2 SDRAM.
J2
VREF
Reference Voltage
VREF is reference voltage for inputs.
A1,E1,J9,M9,R1
VDD
Power Supply
Power Supply: 1.8V ± 0.1V.
A3,E3,J3,N1,P9
VSS
Ground
Ground.
A9,C1,C3,C7,C9,E9,
G1,G3,G7,G9
VDDQ
DQ Power Supply
DQ Power Supply: 1.8V ± 0.1V.
A7,B2,B8,D2,D8,E7,
F2,F8,H2,H8
VSSQ
DQ Ground
DQ Ground. Isolated on the device for improved noise immunity.
A2,E2,L1,R3,R7,R8
NC
No Connection
No connection.
J7
VSSDL
DLL Ground
DLL Ground.
J1
VDDL
DLL Power Supply
DLL Power Supply: 1.8V ± 0.1V.
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 8 -
7. BLOCK DIAGRAM
CKE
A10
DLL
CLOCK
BUFFER
COMMAND
DECODER
ADDRESS
BUFFER
REFRESH
COUNTER
COLUMN
COUNTER
CONTROL
SIGNAL
GENERATOR
MODE
REGISTER
COLUMN DECODER
SENSE AMPLIFIER
CELL ARRAY
BANK #2
COLUMN DECODER
SENSE AMPLIFIER
CELL ARRAY
BANK #0
COLUMN DECODER
SENSE AMPLIFIER
CELL ARRAY
BANK #3
DATA CONTROL
CIRCUIT
DQ
BUFFER
COLUMN DECODER
SENSE AMPLIFIER
CELL ARRAY
BANK #1
NOTE: The cell array configuration is 8192 * 512 * 16
ROW DECODER ROW DECODER
ROW DECODERROW DECODER
A0
A9
A11
A12
BA0
BA1
CS
RAS
CAS
WE
CLK
CLK
PREFETCH REGISTER
ODT
CONTROL
DQ0
|
DQ15
LDQS
LDQS
UDQS
UDQS
LDM
UDM
ODT
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 9 -
8. FUNCTIONAL DESCRIPTION
8.1 Power-up and Initialization Sequence
DDR2 SDRAMs must be powered up and initialized in a predefined manner. Operational procedures
other than those specified may result in undefined operation. The following sequence is required for
Power-up and Initialization.
1. Apply power and attempt to maintain CKE below 0.2 × VDDQ and ODT*1 at a LOW state (all other
inputs may be undefined.) Either one of the following sequence is required for Power-up.
A. The VDD voltage ramp time must be no greater than 200 mS from when VDD ramps from 300
mV to VDD min; and during the VDD voltage ramp, |VDD -VDDQ| ≤ 0.3 volts.
VDD, VDDL and VDDQ are driven from a single power converter output
VTT is limited to 0.95V max
VREF*2 tracks VDDQ/2
VDDQ ≥ VREF must be met at all times
B. Voltage levels at I/Os and outputs must be less than VDDQ during voltage ramp time to avoid
DRAM latch-up. During the ramping of the supply voltages, VDD ≥ VDDL ≥ VDDQ must be
maintained and is applicable to both AC and DC levels until the ramping of the supply voltages
is complete.
Apply VDD/VDDL*3 before or at the same time as VDDQ
Apply VDDQ*4 before or at the same time as VTT
VREF*2 tracks VDDQ/2
VDDQ ≥ VREF must be met at all times
Apply VTT
The VTT voltage ramp time from when VDDQ min is achieved on VDDQ to when VTT min is
achieved on VTT must be no greater than 500 mS
2. Start Clock and maintain stable condition for 200 µS (min.).
3. After stable power and clock (CLK,
CLK
), apply NOP or Deselect and take CKE HIGH.
4. Wait minimum of 400 nS then issue precharge all command. NOP or Deselect applied during 400
nS period.
5. Issue an EMRS command to EMR (2). (To issue EMRS command to EMR (2), provide LOW to
BA0, HIGH to BA1.)
6. Issue an EMRS command to EMR (3). (To issue EMRS command to EMR (3), provide HIGH to
BA0 and BA1.)
7. Issue an EMRS command to EMR (1) to enable DLL. (To issue DLL Enable command, provide
LOW to A0, HIGH to BA0 and LOW to BA1. And A9=A8=A7=LOW must be used when issuing this
command.)
8. Issue a Mode Register Set command for DLL reset. (To issue DLL Reset command, provide HIGH
to A8 and LOW to BA0 and BA1.)
9. Issue a precharge all command.
10. Issue 2 or more Auto Refresh commands.
11. Issue a MRS command with LOW to A8 to initialize device operation. (i.e. to program operating
parameters without resetting the DLL.)
12. At least 200 clocks after step 8, execute OCD Calibration (Off Chip Driver impedance adjustment).
If OCD calibration is not used, EMRS to EMR (1) to set OCD Calibration Default
(A9=A8=A7=HIGH) followed by EMRS to EMR (1) to exit OCD Calibration Mode
(A9=A8=A7=LOW) must be issued with other operating parameters of EMR(1).
13. The DDR2 SDRAM is now ready for normal operation.
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 10 -
Notes:
1. To guarantee ODT off, VREF must be valid and a LOW level must be applied to the ODT pin.
2. VREF must be within ± 300 mV with respect to VDDQ/2 during supply ramp time.
3. VDD/VDDL voltage ramp time must be no greater than 200 mS from when VDD ramps from 300 mV to VDD min.
4. The VDDQ voltage ramp time from when VDD min is achieved on VDD to when VDDQ min is achieved on VDDQ must be no
greater than 500 mS
tCH tCL
tIS
tIS
400nS
NOP PRE
ALL EMRS MRS PRE
ALL REF MRSREF EMRS EMRS ANY
CMD
tRP tMRD tMRD
tRP tRFC tRFC tOIT
Follow OCD
Flow chart OCD
CAL. Mode
Exit
OCD
Default
min 200 Cycle
DLL
Reset
DLL
Enable
CLK
CLK
CKE
Command
ODT
tMRD
Figure 1 – Initialization sequence after power-up
8.2 Mode Register and Extended Mode Registers Operation
For application flexibility, burst length, burst type, CAS Latency, DLL reset function, write recovery
time (WR) are user defined variables and must be programmed with a Mode Register Set (MRS)
command. Additionally, DLL disable function, driver impedance, additive CAS Latency, ODT (On Die
Termination), single-ended strobe and OCD (off chip driver impedance adjustment) are also user
defined variables and must be programmed with an Extended Mode Register Set (EMRS) command.
Contents of the Mode Register (MR) or Extended Mode Registers EMR (1), EMR (2) and EMR (3) can
be altered by re-executing the MRS or EMRS Commands. Even if the user chooses to modify only a
subset of the MR or EMR (1), EMR (2) and EMR (3) variables, all variables within the addressed
register must be redefined when the MRS or EMRS commands are issued.
MRS, EMRS and Reset DLL do not affect array contents, which mean re-initialization including those
can be executed at any time after power-up without affecting array contents.
8.2.1 Mode Register Set Command (MRS)
(
CS
= "L",
RAS
= "L",
CAS
= "L",
WE
= "L", BA0 = "L", BA1 = "L", A0 to A12 = Register Data)
The mode register stores the data for controlling the various operating modes of DDR2 SDRAM. It
programs CAS Latency, burst length, burst sequence, test mode, DLL reset, Write Recovery (WR) and
various vendor specific options to make DDR2 SDRAM useful for various applications. The default
value in the Mode Register after power-up is not defined, therefore the Mode Register must be
programmed during initialization for proper operation.
The DDR2 SDRAM should be in all bank precharge state with CKE already HIGH prior to writing into
the mode register. The mode register set command cycle time (tMRD) is required to complete the write
operation to the mode register. The mode register contents can be changed using the same command
and clock cycle requirements during normal operation as long as all banks are in the precharge state.
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 11 -
The mode register is divided into various fields depending on functionality. Burst length is defined by
A[2:0] with options of 4 and 8 bit burst lengths. The burst length decodes are compatible with DDR
SDRAM. Burst address sequence type is defined by A3, CAS Latency is defined by A[6:4]. The DDR2
does not support half clock latency mode. A7 is used for test mode. A8 is used for DLL reset. A7 must
be set to LOW for normal MRS operation. Write recovery time WR is defined by A[11:9]. Refer to the
table for specific codes.
BA0 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
PD WR DLL BTCAS Latency Burst LengthTM
A8
0
1
DLL Reset
No
Yes
BA1 BA0
0 0
0 1
1 0
1 1
MRS mode
MR
EMR (1)
EMR (2)
EMR (3)
A12
1
0Active power down exit time
Fast exit (use tXARD)
Slow exit (use tXARDS)
Burst Length
Address Field
Mode Register
Write recovery for Auto-precharge CAS Latency
A6
0
0
0
0
1
1
1
1
A5
0
0
1
1
0
0
1
1
A4
0
1
0
1
0
1
1
0
Latency
Reserved
3
4
5
7
6
Reserved
Reserved
A2
0
0
A1
1
1
A0
0
1
BL
4
8
A11
0
0
0
0
1
1
1
1
A10
0
0
1
1
0
0
1
1
A9
0
1
0
1
0
1
1
0
WR *
Reserved
2
3
4
5
6
8
7
A7
0
1
Mode
Normal
Test
A3
0
1
Burst Type
Sequential
Interleave
0
DDR2-667
DDR2-800
DDR2-1066
DDR2-800
DDR2-1066
DDR2-667
BA1
0
Note:
1. WR (write recovery for Auto-precharge) min is determined by tCK(avg) max and WR max is determined by tCK(avg) min.
WR[cycles] = RU{ tWR[nS] / tCK(avg)[nS] }, where RU stands for round up. The mode register must be programmed to this
value. This is also used with tRP to determine tDAL.
Figure 2 – Mode Register Set (MRS)
8.2.2 Extend Mode Register Set Commands (EMRS)
8.2.2.1 Extend Mode Register Set Command (1), EMR (1)
(
CS
= "L",
RAS
= "L",
CAS
= "L",
WE
= "L", BA0 = "H", BA1 = "L", A0 to A12 = Register data)
The extended mode register (1) stores the data for enabling or disabling the DLL, output driver
strength, additive latency, ODT,
DQS
disable, OCD program. The default value of the extended
mode register (1) is not defined, therefore the extended mode register (1) must be programmed during
initialization for proper operation. The DDR2 SDRAM should be in all bank precharge with CKE
already high prior to writing into the extended mode register (1). The mode register set command
cycle time (tMRD) must be satisfied to complete the write operation to the extended mode register (1).
Extended mode register (1) contents can be changed using the same command and clock cycle
requirements during normal operation as long as all banks are in the precharge state. A0 is used for
DLL enable or disable. A1 is used for enabling a reduced strength output driver. A[5:3] determines the
additive latency, A[9:7] are used for OCD control, A10 is used for
DQS
disable. A2 and A6 are used
for ODT setting.
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8.2.2.2 DLL Enable/Disable
The DLL must be enabled for normal operation. DLL enable is required during power-up initialization,
and upon returning to normal operation after having the DLL disabled. The DLL is automatically
disabled when entering Self Refresh operation and is automatically re-enabled and reset upon exit of
Self Refresh operation. Any time 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 be synchronized
with the external clock. Failing to wait for synchronization to occur may result in a violation of the tAC
or tDQSCK parameters.
BA1BA0 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
0 1 OCD program BTRtt
Address Field
Extended Mode Register (1)
BA1BA0 MRS mode
0 0
00
1
1
1 1
MR
EMR (1)
EMR (2)
EMR (3)
A6 A2
0 0
00
1
1
1 1
WRAdditive Latency
Qoff 0*1DQS Rtt D.I.C DLL
Rtt (nominal)
ODT Disabled
75 ohm
150 ohm
50 ohm*2
0
A0
1
DLL Enable
Enable
Disable
OCD Calibration Program
OCD calibration mode exit; matain setting
Adjust mode*3
OCD Calibration default*4
Drive (1)
Drive (0)
A9 A8 A7
1
0 0 0
1 1
1110 0
0
0
0
0
Driver impedance adjustment
A12
1
0 Output buffer enabled
Qoff (Optional)*5
Output buffer disabled
A10
1
0DQS
Enable
Disable A10
(DQS Enable)
0 (Enable)
1 (Disable)
Strobe Function Matrix
DQS
DQS
DQS
DQS
DQS
Hi-z
Output driver
impedance control
Reduced
Normal
A1
0
1
A5
0
0
0
0
1
1
1
1
A4
0
0
1
1
0
0
1
1
A3
0
1
0
1
0
1
1
0
Latency
0
3
4
Reserved
1
2
Output Driver Impedance Control
Driver
size
100%
60%
Additive Latency
5
6
DDR2-/667/800
DDR2-1066
Notes:
1. A11 default is “0” RDQS disabled.
2. Optional for DDR2-667, mandatory for DDR2-800 and DDR2-1066.
3. When Adjust mode is issued, AL from previously set value must be applied.
4. After setting to default, OCD calibration mode needs to be exited by setting A9-A7 to 000. Refer to the section 8.2.3 for
detailed information.
5. Output disabled - DQs, LDQS,
LDQS
, UDQS,
UDQS
. This feature is used in conjunction with DIMM IDD measurements
when IDDQ is not desired to be included. Figure 3 – EMR (1)
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8.2.2.3 Extend Mode Register Set Command (2), EMR (2)
(
CS
= "L",
RAS
= "L",
CAS
= "L",
WE
= "L", BA0 = "L", BA1 = "H", A0 to A12 = Register data)
The extended mode register (2) controls refresh related features. The default value of the extended
mode register (2) is not defined, therefore the extended mode register (2) must be programmed during
initialization for proper operation.
The DDR2 SDRAM should be in all bank precharge state with CKE already high prior to writing into
the extended mode register (2). The mode register set command cycle time (tMRD) must be satisfied to
complete the write operation to the extended mode register (2). Mode register contents can be
changed using the same command and clock cycle requirements during normal operation as long as
all banks are in the precharge state.
A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
0 SELF
0*1
Address Field
Extended Mode Register (2)
0*1
A7
1
0Disable
High Temperature Self Refresh Rate Enable
Enable*2
BA0
1
BA1BA0MRS mode
0 0
00
1
1
1 1
MRS
EMR (1)
EMR (2)
EMR (3)
BA1
Notes:
1. The rest bits in EMR (2) is reserved for future use and all bits in EMR (2) except A7, BA0 and BA1 must be programmed to
“0” when setting the extended mode register (2) during initialization.
2. When DRAM is operated at 85°C < TCASE ≤ 95°C the extended Self Refresh rate must be enabled by setting bit A7 to “1”
before the Self Refresh mode can be entered. Figure 4 – EMR (2)
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8.2.2.4 Extend Mode Register Set Command (3), EMR (3)
(
CS
= "L",
RAS
= "L",
CAS
= "L",
WE
= "L", BA0 = "H", BA1 = "H", A0 to A12 = Register data)
No function is defined in extended mode register (3). The default value of the EMR (3) is not defined,
therefore the EMR (3) must be programmed during initialization for proper operation.
BA1BA0 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
1 1
Address Field
Extended Mode Register (3)
0*1
Note:
1. All bits in EMR (3) except BA0 and BA1 are reserved for future use and must be set to “0” when programming the EMR (3).
Figure 5 – EMR (3)
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8.2.3 Off-Chip Driver (OCD) Impedance Adjustment
DDR2 SDRAM supports driver calibration feature and the flow chart in Figure 6 is an example of the
sequence. Every calibration mode command should be followed by “OCD calibration mode exit”
before any other command being issued. MRS should be set before entering OCD impedance
adjustment and On Die Termination (ODT) should be carefully controlled depending on system
environment.
Start
ALL OK
All MR shoud be programmed before entering OCD impedance adjustment and ODT should
be carefully controlled depending on system environment
EMRS: Drive(0)
DQ &DQS Low; DQS High
EMRS: OCD calibration mode exit
Test
Need Calibration
EMRS: OCD calibration mode exit
EMRS:
Enter Adjust Mode
BL=4 code input to all DQs
Inc, Dec or NOP
EMRS: OCD calibration mode exit
ALL OK
EMRS: Drive(1)
DQ &DQS High; DQS Low
Test
Need Calibration
EMRS: OCD calibration mode exit
EMRS:
Enter Adjust Mode
BL=4 code input to all DQs
Inc, Dec or NOP
EMRS: OCD calibration mode exit
EMRS: OCD calibration mode exit
End
Figure 6 – OCD Impedance Adjustment Flow Chart
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8.2.3.1 Extended Mode Register for OCD Impedance Adjustment
OCD impedance adjustment can be done using the following EMRS mode. In drive mode all outputs
are driven out by DDR2 SDRAM. In Drive (1) mode, all DQ, DQS signals are driven HIGH and all
DQS
signals are driven LOW. In Drive (0) mode, all DQ, DQS signals are driven LOW and all
DQS
signals are driven HIGH. In adjust mode, BL = 4 of operation code data must be used. In case of OCD
calibration default, output driver characteristics have a nominal impedance value of 18 Ohms during
nominal temperature and voltage conditions. OCD applies only to normal full strength output drive
setting defined by EMR (1) and if reduced strength is set, OCD default driver characteristics are not
applicable. When OCD calibration adjust mode is used, OCD default output driver characteristics are
not applicable. After OCD calibration is completed or driver strength is set to default, subsequent
EMRS commands not intended to adjust OCD characteristics must specify A[9:7] as ’000’ in order to
maintain the default or calibrated value.
Table 1 – OCD Drive Mode Program
A9
A8
A7
Operation
0
0
0
OCD calibration mode exit
0
0
1
Drive (1) DQ, DQS HIGH and
DQS
LOW
0
1
0
Drive (0) DQ, DQS LOW and
DQS
HIGH
1
0
0
Adjust mode
1
1
1
OCD calibration default
8.2.3.2 OCD Impedance Adjust
To adjust output driver impedance, controllers must issue the ADJUST EMRS command along with a
4 bit burst code to DDR2 SDRAM as in table 2. For this operation, Burst Length has to be set to BL =
4 via MRS command before activating OCD and controllers must drive the burst code to all DQs at the
same time. DT0 in table 2 means all DQ bits at bit time 0, DT1 at bit time 1, and so forth. The driver
output impedance is adjusted for all DDR2 SDRAM DQs simultaneously and after OCD calibration, all
DQs and DQS’s of a given DDR2 SDRAM will be adjusted to the same driver strength setting. The
maximum step count for adjustment is 16 and when the limit is reached, further increment or
decrement code has no effect. The default setting may be any step within the 16 step range. When
Adjust mode command is issued, AL from previously set value must be applied.
Table 2 – OCD Adjust Mode Program
4 bit burst code inputs to all DQs
Operation
DT0
DT1
DT2
DT3
Pull-up driver strength
Pull-down driver strength
0
0
0
0
NOP (No operation)
NOP (No operation)
0
0
0
1
Increase by 1 step
NOP
0
0
1
0
Decrease by 1 step
NOP
0
1
0
0
NOP
Increase by 1 step
1
0
0
0
NOP
Decrease by 1 step
0
1
0
1
Increase by 1 step
Increase by 1 step
0
1
1
0
Decrease by 1 step
Increase by 1 step
1
0
0
1
Increase by 1 step
Decrease by 1 step
1
0
1
0
Decrease by 1 step
Decrease by 1 step
Other Combinations
Reserved
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For proper operation of adjust mode, WL = RL - 1 = AL + CL - 1 clocks and tDS/tDH should be met as
shown in Figure 7. For input data pattern for adjustment, DT0 - DT3 is a fixed order and is not affected
by burst type (i.e., sequential or interleave).
OCD adjust mode OCD calibration mode exit
WR
WL DQS
tDS tDH
DT0
CLK
DQS_in
CMD
DQ_in
DM
NOP
EMRSNOP
NOP
NOP
NOP
NOP
NOPEMRS
CLK
DT1 DT2 DT3
Figure 7 – OCD Adjust Mode
8.2.3.3 Drive Mode
Drive mode, both Drive (1) and Drive (0), is used for controllers to measure DDR2 SDRAM Driver
impedance. In this mode, all outputs are driven out tOIT after “enter drive mode” command and all
output drivers are turned-off tOIT after “OCD calibration mode exit” command as shown in Figure 8.
Enter Drive mode OCD calibration mode exit
EMRSEMRS NOP NOP NOP NOP NOPNOP NOP
CLK
DQS
DQS
CMD
DQ
tOIT tOIT
DQs high for Drive (1)
DQs low for Drive (0)
DQS high & DQS low for Drive (1), DQS low & DQS high for Drive (0)
CLK
HI-Z
Figure 8 – OCD Drive Mode
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8.2.4 On-Die Termination (ODT)
On-Die Termination (ODT) is a new feature on DDR2 components that allows a DRAM to turn on/off
termination resistance for each DQ, UDQS/
UDQS
, LDQS/
LDQS
, UDM and LDM signal via the ODT
control pin.
UDQS
and
LDQS
are terminated only when enabled in the EMR (1) by address bit A10
= 0. The ODT feature is designed to improve signal integrity of the memory channel by allowing the
DRAM controller to independently turn on/off termination resistance for any or all DRAM devices.
The ODT function can be used for all active and standby modes. ODT is turned off and not supported
in Self Refresh mode. (Example timing waveforms refer to 11.2, 11.3 ODT Timing for
Active/Standby/Power Down Mode and 11.4, 11.5 ODT timing mode switch at entering/exiting power
down mode diagram in Chapter 11)
DRAM
Input
Buffer
Input
Pin
VDDQ
sw1
Rval3
VDDQ VDDQ
sw2sw3
Rval1 Rval2
Rval1 Rval2 Rval3
sw1sw2sw3
VSSQ VSSQ VSSQ
Switch (sw1, sw2, sw3) is enabled by ODT pin.
Selection among sw1, sw2, and sw3 is determined by “Rtt (nominal)” in EMR (1).
Termination included on all DQs, DM, DQS,
DQS
pins.
Figure 9 – Functional Representation of ODT
8.2.5 ODT related timings
8.2.5.1 MRS command to ODT update delay
During normal operation the value of the effective termination resistance can be changed with an
EMRS command. The update of the Rtt setting is done between tMOD,min and tMOD,max, and CKE
must remain HIGH for the entire duration of tMOD window for proper operation. The timings are shown
in the following timing diagram.
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CMD
CLK
CLK
ODT
Rtt Updating
New setting
tIS
tMOD,min
tMOD,max
tAOFD
EMRS NOP NOP NOP NOP NOP
Old setting
1) EMRS command directed to EMR(1), which updates the information in EMR(1)[A6,A2], i.e. Rtt (Nominal).
2) "setting" in this diagram is the Register and I/O setting, not what is measured from outside.
Figure 10 – ODT update delay timing - tMOD
However, to prevent any impedance glitch on the channel, the following conditions must be met.
tAOFD must be met before issuing the EMRS command.
ODT must remain LOW for the entire duration of tMOD window, until tMOD,max is met.
Now the ODT is ready for normal operation with the new setting, and the ODT signal may be raised
again to turned on the ODT. Following timing diagram shows the proper Rtt update procedure.
CLK
CLK
CMD
ODT
Rtt Old setting New setting
tAOND
tIS
tMOD,max
tAOFD
EMRS NOP NOP NOP NOP NOP
1) EMRS command directed to EMR(1), which updates the information in EMR(1)[A6,A2], i.e. Rtt (Nominal).
2) "setting" in this diagram is what is measured from outside.
Figure 11 – ODT update delay timing - tMOD, as measured from outside
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8.3 Command Function
8.3.1 Bank Activate Command
(
CS
= "L",
RAS
= "L",
CAS
= "H",
WE
= "H", BA0, BA1 = Bank, A0 to A12 be row address)
The Bank Activate command must be applied before any Read or Write operation can be executed.
Immediately after the bank active command, the DDR2 SDRAM can accept a read or write command
on the following clock cycle. If a Read/Write command is issued to a bank that has not satisfied the
tRCDmin specification, then additive latency must be programmed into the device to delay when the
Read/Write command is internally issued to the device. The additive latency value must be chosen to
assure tRCDmin is satisfied. Additive latencies of 0, 1, 2, 3, 4, 5 and 6 are supported. Once a bank has
been activated it must be precharged before another Bank Activate command can be applied to the
same bank. The bank active and precharge times are defined as tRAS and tRP, respectively. The
minimum time interval between successive Bank Activate commands to the same bank is determined
by the RAS cycle time of the device (tRC). The minimum time interval between Bank Activate
commands is tRRD.
T0 T1 T2 T3 Tn Tn+1 Tn+2 Tn+3
Bank A
Row Addr. Bank A
Col. Addr. Bank B
Row Addr. Bank B
Col. Addr. Bank A
Addr. Bank B
Addr. Bank A
Row Addr.
CAS - CAS delay time(tCCD)
tRCD = 1 Additive Latency delay(AL) Read Begins
Bank A
Activate
Bank A
Post CAS
Read
Bank B
Activate
Bank B
Post CAS
Read
Bank A
Precharge Bank B
Precharge Bank A
Activate
Bank Active (≥ tRAS)
RAS Cycle time (≥ tRC)
Bank Precharge time (≥ tRP)
Command
Address
RAS - RAS delay time(≥ tRRD)
CLK
CLK
Internal RAS - RAS delay (≥ tRCDmin)
Figure 12 – Bank activate command cycle: tRCD = 3, AL = 2, tRP = 3, tRRD = 2, tCCD = 2
8.3.2 Read Command
(
CS
= "L",
RAS
= "H",
CAS
= "L",
WE
= "H", BA0, BA1 = Bank, A10 = "L", A0 to A8 = Column
Address)
The READ command is used to initiate a burst read access to an active row. The value on BA0, BA1
inputs selects the bank, and the A0 to A8 address inputs determine the starting column address. The
address 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.
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8.3.3 Write Command
(
CS
= "L",
RAS
= "H",
CAS
= "L",
WE
= "L", BA0, BA1 = Bank, A10 = "L", A0 to A8 = Column
Address)
The WRITE command is used to initiate a burst write access to an active row. The value on BA0, BA1
inputs selects the bank, and the A0 to A8 address inputs determine the starting column address. The
address 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.
8.3.4 Burst Read with Auto-precharge Command
(
CS
= "L",
RAS
= "H",
CAS
="L",
WE
= "H", BA0, BA1 = Bank, A10 = "H", A0 to A8 = Column
Address)
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 edge which is (AL + BL/2) cycles
later than the read with AP command if tRAS(min) and tRTP(min) are satisfied.
8.3.5 Burst Write with Auto-precharge Command
(
CS
= "L",
RAS
= "H",
CAS
= "L",
WE
= "L", BA0, BA1 = Bank, A10 = "H", A0 to A8 = Column
Address)
If A10 is HIGH when a Write Command is issued, the Write with Auto-precharge function is engaged.
The DDR2 SDRAM automatically begins precharge operation after the completion of the burst write
plus write recovery time (WR) programmed in the mode register.
8.3.6 Precharge All Command
(
CS
= "L",
RAS
= "L",
CAS
= "H",
WE
= "L", BA0, BA1 = Don’t Care, A10 = "H", A0 to A9 and
A11 to A12 = Don’t Care)
The Precharge All command precharge all banks simultaneously. Then all banks are switched to the
idle state.
8.3.7 Self Refresh Entry Command
(
CS
= "L",
RAS
= "L",
CAS
= "L",
WE
= "H", CKE = "L", BA0, BA1, A0 to A12 = Don’t Care)
The Self Refresh command can be used to retain data, even if the rest of the system is powered
down. When in the Self Refresh mode, the DDR2 SDRAM retains data without external clocking. The
DDR2 SDRAM device has a built-in timer to accommodate Self Refresh operation. ODT must be
turned off before issuing Self Refresh command, by either driving ODT pin LOW or using an EMRS
command. Once the command is registered, CKE must be held LOW to keep the device in Self
Refresh mode. The DLL is automatically disabled upon entering Self Refresh and is automatically
enabled upon exiting Self Refresh. When the DDR2 SDRAM has entered Self Refresh mode, all of the
external signals except CKE, are “Don’t Care”.
The clock is internally disabled during self refresh operation to save power. The user may change the
external clock frequency or halt the external clock one clock after Self Refresh entry is registered;
however, the clock must be restarted and stable before the device can exit self refresh operation.
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8.3.8 Self Refresh Exit Command
(CKE = "H",
CS
= "H" or CKE = "H",
CS
= "L",
RAS
= "H",
CAS
= "H",
WE
= "H", BA0, BA1,
A0 to A12 = Don’t Care)
The procedure for exiting Self Refresh requires a sequence of commands. First, the clock must be
stable prior to CKE going back HIGH. Once Self Refresh Exit is registered, a delay of at least tXSNR
must be satisfied before a valid command can be issued to the device to allow for any internal refresh
in progress. CKE must remain HIGH for the entire Self Refresh exit period tXSRD for proper operation
except for self refresh re-entry.
Upon exit from Self Refresh, the DDR2 SDRAM can be put back into Self Refresh mode after waiting
at least tXSNR period and issuing one refresh command (refresh period of tRFC). NOP or Deselect
commands must be registered on each positive clock edge during the Self Refresh exit interval tXSNR.
ODT should be turned off during tXSRD.
The use of Self Refresh mode introduces the possibility that an internally timed refresh event can be
missed when CKE is raised for exit from Self Refresh mode. Upon exit from Self Refresh, the DDR2
SDRAM requires a minimum of one extra auto refresh command before it is put back into Self Refresh
mode.
8.3.9 Refresh Command
(
CS
= "L",
RAS
= "L",
CAS
= "L",
WE
= "H", CKE = "H", BA0, BA1, A0 to A12 = Don’t Care)
Refresh is used during normal operation of the DDR2 SDRAM. This command is non persistent, so it
must be issued each time a refresh is required.
The refresh addressing is generated by the internal refresh controller. This makes the address bits
“Don’t Care” during an Auto Refresh command. The DDR2 SDRAM requires Auto Refresh cycles at
an average periodic interval of tREFI (max.).
When the refresh cycle has completed, all banks of the DDR2 SDRAM will be in the precharged (idle)
state. A delay between the auto refresh command (REF) and the next activate command or
subsequent auto refresh command must be greater than or equal to the auto refresh cycle time (tRFC).
To allow for improved efficiency in scheduling and switching between tasks, some flexibility in the
absolute refresh interval is provided. A maximum of eight Refresh commands can be posted to any
given DDR2 SDRAM, meaning that the maximum absolute interval between any Refresh command
and the next Refresh command is 9 x tREFI.
T0 T1 T2 T3
CLK/CLK
CKE
CMD
≥ tRP ≥ tRFC ≥ tRFC
NOP NOP NOP ANY
REFREF
Precharge
"HIGH"
Tm Tn Tn + 1
Figure 13 – Refresh command
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8.3.10 No-Operation Command
(
CS
= "L",
RAS
= "H",
CAS
= "H",
WE
= "H", CKE, BA0, BA1, A0 to A12 = Don’t Care)
The No-Operation command simply performs no operation (same command as Device Deselect).
8.3.11 Device Deselect Command
(
CS
= "H",
RAS
,
CAS
,
WE
, CKE, BA0, BA1, A0 to A12 = Don’t Care)
The Device Deselect command disables the command decoder so that the
RAS
,
CAS
,
WE
and
Address inputs are ignored. This command is similar to the No-Operation command.
8.4 Read and Write access modes
The DDR2 SDRAM provides a fast column access operation. A single Read or Write Command will
initiate a serial read or write operation on successive clock cycles. The boundary of the burst cycle is
strictly restricted to specific segments of the page length.
The 4 Mbit x 16 I/O x 4 Bank chip has a page length of 512 bits (defined by CA0 to CA8)*. The page
length of 512 is divided into 128 or 64 uniquely addressable boundary segments depending on burst
length, 128 for 4 bit burst, 64 for 8 bit burst respectively. A 4-bit or 8-bit burst operation will occur
entirely within one of the 128 or 64 groups beginning with the column address supplied to the device
during the Read or Write Command (CA0 to CA8). The second, third and fourth access will also occur
within this group segment. However, the burst order is a function of the starting address, and the burst
sequence.
A new burst access must not interrupt the previous 4 bit burst operation in case of BL = 4 setting.
However, in case of BL = 8 setting, two cases of interrupt by a new burst access are allowed, one
reads interrupted by a read, the other writes interrupted by a write with 4 bit burst boundary
respectively. The minimum
CAS
to
CAS
delay is defined by tCCD, and is a minimum of 2 clocks for
read or write cycles.
Note: Page length is a function of I/O organization and column addressing
4M bits × 16 organization (CA0 to CA8); Page Length = 512 bits
8.4.1 Posted
CAS
Posted
CAS
operation is supported to make command and data bus efficient for sustainable
bandwidths in DDR2 SDRAM. In this operation, the DDR2 SDRAM allows a
CAS
read or write
command to be issued immediately after the
RAS
bank activate command (or any time during the
RAS
-
CAS
-delay time, tRCD, period). The command is held for the time of the Additive Latency (AL)
before it is issued inside the device. The Read Latency (RL) is controlled by the sum of AL and the
CAS Latency (CL). Therefore if a user chooses to issue a Read/Write command before the tRCDmin,
then AL (greater than 0) must be written into the EMR (1). The Write Latency (WL) is always defined
as RL -1 (Read Latency -1) where Read Latency is defined as the sum of Additive Latency plus CAS
Latency (RL = AL + CL). Read or Write operations using AL allow seamless bursts. (Example timing
waveforms refer to 11.10 and 11.11 seamless burst read/write operation diagram in Chapter 11)
8.4.1.1 Examples of posted
CAS
operation
Examples of a read followed by a write to the same bank where AL = 2 and where AL = 0 are shown
in Figures 14 and 15, respectively.
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CMD
1 2 3 4 5 67 8 9 10 11 120
-1
CLK /CLK
DQS/DQS
DQ
AL=2 CL=3
WL=RL-1=4
≥ tRCD
RL=AL+CL=5
Dout0 Din0
Active
A-Bank
Read
A-Bank Write
A-Bank
Din1 Din2 Din3
Dout1 Dout2 Dout3
[AL = 2 and CL = 3, RL = (AL + CL) = 5, WL = (RL - 1) = 4, BL = 4]
Figure 14 – Example 1: Read followed by a write to the same bank,
where AL = 2 and CL = 3, RL = (AL + CL) = 5, WL = (RL - 1) = 4, BL = 4
1 2 3 4 5 6 7 8 9 10 11 12
0
-1
CL=3
WL=RL-1=2
≥ tRCD RL=AL+CL=3
AL=0
CMD
CLK/CLK
DQ Dout0 Dout1 Dout2 Dout3 Din0 Din1 Din2 Din3
Write
A-Bank
Read
A-Bank
Active
A-Bank
DQS/DQS
AL = 0 and CL = 3, RL = (AL + CL) = 3, WL = (RL - 1) = 2, BL = 4]
Figure 15 – Example 2: Read followed by a write to the same bank,
where AL = 0 and CL = 3, RL = (AL + CL) = 3, WL = (RL - 1) = 2, BL = 4
8.4.2 Burst mode operation
Burst mode operation is used to provide a constant flow of data to memory locations (write cycle), or
from memory locations (read cycle). The parameters that define how the burst mode will operate are
burst sequence and burst length. The DDR2 SDRAM supports 4 bit and 8 bit burst modes only. For 8
bit burst mode, full interleave address ordering is supported, however, sequential address ordering is
nibble based for ease of implementation. The burst length is programmable and defined by MR A[2:0].
The burst type, either sequential or interleaved, is programmable and defined by MR [A3]. Seamless
burst read or write operations are supported.
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Unlike DDR1 devices, interruption of a burst read or writes cycle during BL = 4 mode operation is
prohibited. However in case of BL = 8 mode, interruption of a burst read or write operation is limited to
two cases, reads interrupted by a read, or writes interrupted by a write. (Example timing waveforms
refer to 11.12 and 11.13 Burst read and write interrupt timing diagram in Chapter 11)
Therefore the Burst Stop command is not supported on DDR2 SDRAM devices.
Table 3 – Burst Length and Sequence
Burst Length
Starting Address
(A2 A1 A0)
Sequential Addressing
(decimal)
Interleave Addressing
(decimal)
4
x00
0, 1, 2, 3
0, 1, 2, 3
x01
1, 2, 3, 0
1, 0, 3, 2
x10
2, 3, 0, 1
2, 3, 0, 1
x11
3, 0, 1, 2
3, 2, 1, 0
8
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
8.4.3 Burst read mode operation
Burst Read is initiated with a READ command. The address inputs determine the starting column
address for the burst. The delay from the start of the command to when the data from the first cell
appears on the outputs is equal to the value of the read latency (RL). The data strobe output (DQS) is
driven LOW one clock cycle before valid data (DQ) is driven onto the data bus. The first bit of the burst
is synchronized with the rising edge of the data strobe (DQS). Each subsequent data-out appears on
the DQ pin in phase with the DQS signal in a source synchronous manner. The RL is equal to an
additive latency (AL) plus CAS Latency (CL). The CL is defined by the Mode Register Set (MRS). The
AL is defined by the Extended Mode Register EMR (1). (Example timing waveforms refer to 11.6 and
11.7 Data output (read) timing and Burst read operation diagram in Chapter 11)
8.4.4 Burst write mode operation
Burst Write is initiated with a WRITE command. The address inputs determine the starting column
address for the burst. Write Latency (WL) is defined by a Read Latency (RL) minus one and is equal
to (AL + CL -1); and is the number of clocks of delay that are required from the time the write
command is registered to the clock edge associated to the first DQS strobe. A data strobe signal
(DQS) should be driven LOW (preamble) nominally half clock prior to the WL. The first data bit of the
burst cycle must be applied to the DQ pins at the first rising edge of the DQS following the preamble.
The tDQSS specification must be satisfied for each positive DQS transition to its associated clock edge
during write cycles. The subsequent burst bit data are issued on successive edges of the DQS until
the burst length is completed, which is 4 or 8 bit burst. When the burst has finished, any additional
data supplied to the DQ pins will be ignored. The DQ Signal is ignored after the burst write operation is
complete. The time from the completion of the burst write to bank precharge is the write recovery time
(WR). (Example timing waveforms refer to 11.8 and 11.9 Data input (write) timing and Burst write
operation diagram in Chapter 11)
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8.4.5 Write data mask
One write data mask (DM) pin for each 8 data bits (DQ) will be supported on DDR2 SDRAM,
consistent with the implementation on DDR1 SDRAM. It has identical timings on write operations as
the data bits, and though used in a unidirectional manner, is internally loaded identically to data bits to
insure matched system timing. DM is not used during read cycles. (Example timing waveform refer to
11.14 Write operation with Data Mask diagram in Chapter 11)
8.5 Burst Interrupt
Read or Write burst interruption is prohibited for burst length of 4 and only allowed for burst length of 8
under the following conditions:
1. Read burst of 8 can only be interrupted by another Read command. Read burst interruption by
Write or Precharge Command is prohibited.
2. Write burst of 8 can only be interrupted by another Write command. Write burst interruption by
Read or Precharge Command is prohibited.
3. Read burst interrupt must occur exactly two clocks after the previous Read command. Any other
Read burst interrupt timings are prohibited.
4. Write burst interrupt must occur exactly two clocks after the previous Write command. Any other
Write burst interrupt timings are prohibited.
5. Read or Write burst interruption is allowed to any bank inside the DDR2 SDRAM.
6. Read or Write burst with Auto-precharge enabled is not allowed to interrupt.
7. Read burst interruption is allowed by a Read with Auto-precharge command.
8. Write burst interruption is allowed by a Write with Auto-precharge command.
9. All command timings are referenced to burst length set in the mode register. They are not
referenced to the actual burst. For example below:
Minimum Read to Precharge timing is AL + BL/2 where BL is the burst length set in the
mode register and not the actual burst (which is shorter because of interrupt).
Minimum Write to Precharge timing is WL + BL/ 2 + tWR, where tWR starts with the rising
clock after the un-interrupted burst end and not from the end of the actual burst end.
(Example timing waveforms refer to 11.12 and 11.13 Burst read and write interrupt timing diagram in
Chapter 11)
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8.6 Precharge operation
The Precharge Command is used to precharge or close a bank that has been activated. The
Precharge Command can be used to precharge each bank independently or all banks simultaneously.
Three address bits A10, BA0 and BA1 are used to define which bank to precharge when the
command is issued. Table 4 – Bank selection for precharge by address bits
A10
BA1
BA0
Precharge Bank(s)
LOW
LOW
LOW
Bank 0 only
LOW
LOW
HIGH
Bank 1 only
LOW
HIGH
LOW
Bank 2 only
LOW
HIGH
HIGH
Bank 3 only
HIGH
Don’t Care
Don’t Care
All Banks
8.6.1 Burst read operation followed by precharge
Minimum Read to Precharge command spacing to the same bank = AL + BL/2 + max(RTP, 2) - 2 clks
For the earliest possible precharge, the precharge command may be issued on the rising edge which
is “Additive Latency (AL) + BL/2 + max(RTP, 2) - 2 clocks” after a Read command. A new bank active
(command) may be issued to the same bank after the RAS precharge time (tRP). A precharge
command cannot be issued until tRAS is satisfied.
The minimum Read to Precharge spacing has also to satisfy a minimum analog time from the rising
clock edge that initiates the last 4-bit prefetch of a Read to Precharge command. This time is called
tRTP (Read to Precharge). 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 clocks after the Read to the
Precharge command. (Example timing waveforms refer to 11.15 to 11.19 Burst read operation
followed by precharge diagram in Chapter 11)
8.6.2 Burst write operation followed by precharge
Minimum Write to Precharge Command spacing to the same bank = WL + BL/2 clks + tWR
For write cycles, a delay must be satisfied from the completion of the last burst write cycle until the
Precharge Command can be issued. This delay is known as a write recovery time (tWR) referenced
from the completion of the burst write to the precharge command. No Precharge command should be
issued prior to the tWR delay. (Example timing waveforms refer to 11.20 to 11.21 Burst write operation
followed by precharge diagram in Chapter 11)
8.7 Auto-precharge operation
Before a new row in an active bank can be opened, the active bank must be precharged using either
the Precharge command or the Auto-precharge function. When a Read or a Write command is given
to the DDR2 SDRAM, the
CAS
timing accepts one extra address, column address A10, to allow the
active bank to automatically begin precharge at the earliest possible moment during the burst read or
write cycle. If A10 is LOW when the READ or WRITE command is issued, then normal Read or Write
burst operation is executed and the bank remains active at the completion of the burst sequence. If
A10 is HIGH when the Read or Write command is issued, then the Auto-precharge function is
engaged. During Auto-precharge, a Read command will execute as normal with the exception that the
active bank will begin to precharge on the rising edge which is CAS Latency (CL) clock cycles before
the end of the read burst.
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Auto-precharge is also implemented during Write commands. The precharge operation engaged by
the Auto-precharge command will not begin until the last data of the burst write sequence is properly
stored in the memory array.
This feature allows the precharge operation to be partially or completely hidden during burst read
cycles (dependent upon CAS Latency) thus improving system performance for random data access.
The
RAS
lockout circuit internally delays the Precharge operation until the array restore operation
has been completed (tRAS satisfied) so that the Auto-precharge command may be issued with any
read or write command.
8.7.1 Burst 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 edge which is (AL + BL/2) cycles
later from the Read with AP command if tRAS(min) and tRTP(min) are satisfied. (Example timing
waveform refer to 11.22 Burst read operation with Auto-precharge diagram in Chapter 11)
If tRAS(min) is not satisfied at the edge, the start point of Auto-precharge operation will be delayed until
tRAS(min) is satisfied.
If tRTP(min) is not satisfied at the edge, the start point of Auto-precharge operation will be delayed until
tRTP(min) is satisfied.
In case the internal precharge is pushed out by tRTP, tRP starts at the point where tRTP ends (not at the
next rising clock edge after this event). So for BL = 4 the minimum time from Read with Auto-
precharge to the next Activate command becomes AL + RU{ (tRTP + tRP) / tCK(avg) } (Example timing
waveform refer to 11.23 Burst read operation with Auto-precharge diagram in Chapter 11.), for BL = 8
the time from Read with Auto-precharge to the next Activate command is AL + 2 + RU{ (tRTP + tRP) /
tCK(avg) }, where RU stands for “rounded up to the next integer”. In any event internal precharge does
not start earlier than two clocks after the last 4-bit prefetch.
A new bank active command may be issued to the same bank if the following two conditions are
satisfied simultaneously.
The
RAS
precharge time (tRP) has been satisfied from the clock at which the Auto-precharge
begins.
The
RAS
cycle time (tRC) from the previous bank activation has been satisfied.
(Example timing waveforms refer to 11.24 to 11.25 Burst read with Auto-precharge followed by an
activation to the same bank (tRC Limit) and (tRP Limit) diagram in Chapter 11)
8.7.2 Burst write with Auto-precharge
If A10 is HIGH when a Write Command is issued, the Write with Auto-Precharge function is engaged.
The DDR2 SDRAM automatically begins precharge operation after the completion of the burst write
plus write recovery time (WR) programmed in the mode register. The bank undergoing Auto-
precharge from the completion of the write burst may be reactivated if the following two conditions are
satisfied.
The data-in to bank activate delay time (WR + tRP) has been satisfied.
The
RAS
cycle time (tRC) from the previous bank activation has been satisfied.
(Example timing waveforms refer to 11.26 to 11.27 Burst write with Auto-precharge (tRC Limit) and
(WR + tRP Limit) diagram in Chapter 11)
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Table 5 – Precharge & Auto-precharge clarifications
From
Command
To Command
Minimum Delay between “From
Command” to “To Command”
Unit
Notes
Read
Precharge (to same Bank as Read)
AL + BL/2 + max(RTP, 2) - 2
clks
1, 2
Precharge All
AL + BL/2 + max(RTP, 2) - 2
clks
1, 2
Read w/AP
Precharge (to same Bank as Read w/AP)
AL + BL/2 + max(RTP, 2) - 2
clks
1, 2
Precharge All
AL + BL/2 + max(RTP, 2) - 2
clks
1, 2
Write
Precharge (to same Bank as Write)
WL + BL/2 + tWR
clks
2
Precharge All
WL + BL/2 + tWR
clks
2
Write w/AP
Precharge (to same Bank as Write w/AP)
WL + BL/2 + WR
clks
2
Precharge All
WL + BL/2 + WR
clks
2
Precharge
Precharge (to same Bank as Precharge)
1
clks
2
Precharge All
1
clks
2
Precharge All
Precharge
1
clks
2
Precharge All
1
clks
2
Notes:
1. RTP[cycles] = RU{ tRTP[nS] / tCK(avg)[nS] }, where RU stands for round up.
2. For a given bank, the precharge period should be counted from the latest precharge command, either one bank precharge or
precharge all, issued to that bank. The precharge period is satisfied after tRP depending on the latest precharge command
issued to that bank.
8.8 Refresh Operation
DDR2 SDRAM requires a refresh of all rows in any rolling 64 mS interval. The necessary refresh can
be generated in one of two ways: by explicit Auto Refresh commands or by an internally timed Self
Refresh mode. Dividing the number of device rows into the rolling 64 mS interval defines the average
refresh interval, tREFI, which is a guideline to controllers for distributed refresh timing.
When
CS
,
RAS
and
CAS
are held LOW and
WE
HIGH at the rising edge of the clock, the chip
enters the Refresh mode (REF). All banks of the DDR2 SDRAM must be precharged and idle for a
minimum of the Precharge time (tRP) before the Refresh command (REF) can be applied. An address
counter, internal to the device, supplies the bank address during the refresh cycle. No control of the
external address bus is required once this cycle has started. (Example timing waveform refer to 11.28
Self Refresh diagram in Chapter 11)
8.9 Power Down Mode
Power-down is synchronously entered when CKE is registered LOW, along with NOP or Deselect
command. CKE is not allowed to go LOW while mode register or extended mode register command
time, or read or write operation is in progress. CKE is allowed to go LOW while any other operation
such as row activation, Precharge or Auto-precharge or Auto Refresh is in progress, but power down
IDD specification will not be applied until finishing those operations.
The DLL should be in a locked state when power-down is entered. Otherwise DLL should be reset
after exiting power-down mode for proper read operation.
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8.9.1 Power Down Entry
Two types of Power Down Mode can be performed on the device: Precharge Power Down Mode and
Active Power Down Mode.
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 CLK,
CLK
, ODT and
CKE. Also the DLL is disabled upon entering Precharge Power Down or slow exit Active Power Down,
but the DLL is kept enabled during fast exit Active Power Down.
In power down mode, CKE LOW and a stable clock signal must be maintained at the inputs of the
DDR2 SDRAM, and ODT should be in a valid state but all other input signals are “Don’t Care”. CKE
LOW must be maintained until tCKE has been satisfied. Maximum power down duration is limited by
the refresh requirements of the device, which allows a maximum of 9 x tREFI if maximum posting of
REF is utilized immediately before entering power down. (Example timing waveforms refer to 11.29
Basic Power Down Entry and Exit diagram and 11.30 Precharged Power Down Entry and Exit diagram
in Chapter 11)
8.9.2 Power Down Exit
The power-down state is synchronously exited when CKE is registered HIGH (along with a NOP or
Deselect command). CKE high must be maintained until tCKE has been satisfied. A valid, executable
command can be applied with power-down exit latency, tXP, tXARD, or tXARDS, after CKE goes HIGH.
Power-down exit latency is defined at AC Characteristics table of this data sheet.
8.10 Input clock frequency change during precharge power down
DDR2 SDRAM input clock frequency can be changed under following condition:
DDR2 SDRAM is in precharged power down mode. ODT must be turned off and CKE must be at logic
LOW level. A minimum of 2 clocks must be waited after CKE goes LOW before clock frequency may
change. SDRAM input clock frequency is allowed to change only within minimum and maximum
operating frequency specified for the particular speed grade. During input clock frequency change,
ODT and CKE must be held at stable LOW levels.
Once input clock frequency is changed, stable new clocks must be provided to DRAM before
precharge power down may be exited and DLL must be RESET via MRS command after precharge
power down exit. Depending on new clock frequency an additional MRS or EMRS command may
need to be issued to appropriately set the WR, CL etc…
During DLL re-lock period, ODT must remain off. After the DLL lock time, the DRAM is ready to
operate with new clock frequency. (Example timing waveform refer to 11.31 Clock frequency change
in precharge Power Down mode diagram in Chapter 11)
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9. OPERATION MODE
9.1 Command Truth Table
COMMAND
CKE
BA1
BA0
A12
A11
A10
A9-A0
CS
RAS
CAS
WE
NOTES
Previous
Cycle
Current
Cycle
Bank Activate
H
H
BA
Row Address
L
L
H
H
1, 2
Single Bank
Precharge
H
H
BA
X
L
X
L
L
H
L
1, 2
Precharge All
Banks
H
H
X
X
H
X
L
L
H
L
1
Write
H
H
BA
Column
L
Column
L
H
L
L
1, 2, 3
Write with Auto-
precharge
H
H
BA
Column
H
Column
L
H
L
L
1, 2, 3
Read
H
H
BA
Column
L
Column
L
H
L
H
1, 2, 3
Read with Auto-
precharge
H
H
BA
Column
H
Column
L
H
L
H
1, 2, 3
(Extended)
Mode Register
Set
H
H
BA
OP Code
L
L
L
L
1, 2
No Operation
H
X
X
X
X
X
L
H
H
H
1
Device Deselect
H
X
X
X
X
X
H
X
X
X
1
Refresh
H
H
X
X
X
X
L
L
L
H
1
Self Refresh
Entry
H
L
X
X
X
X
L
L
L
H
1, 4
Self Refresh
Exit
L
H
X
X
X
X
H
X
X
X
1, 4, 5
L
H
H
H
Power Down
Mode Entry
H
L
X
X
X
X
H
X
X
X
1, 6
L
H
H
H
Power Down
Mode Exit
L
H
X
X
X
X
H
X
X
X
1, 6
L
H
H
H
Notes:
1. All DDR2 SDRAM commands are defined by states of
CS
,
RAS
,
CAS
,
WE
and CKE at the rising edge of the clock.
2. Bank addresses BA[1:0] determine which bank is to be operated upon. For (E)MRS BA selects an (Extended) Mode Register.
3. Burst reads or writes at BL = 4 can not be terminated or interrupted. See “Burst Interrupt” in section 8.5 for details.
4. VREF must be maintained during Self Refresh operation.
5. Self Refresh Exit is asynchronous.
6. The Power Down does not perform any refresh operations. The duration of Power Down Mode is therefore limited by the
refresh requirements outlined in section 8.9.
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9.2 Clock Enable (CKE) Truth Table for Synchronous Transitions
CURRENT
STATE2
CKE
COMMAND (N) 3
RAS
,
CAS
,
WE
,
CS
ACTION (N) 3
NOTES
Previous Cycle 1
(N-1)
Current Cycle 1
(N)
Power Down
L
L
X
Maintain Power Down
11, 13, 15
L
H
DESELECT or NOP
Power Down Exit
4, 8, 11, 13
Self Refresh
L
L
X
Maintain Power Down
11, 15, 16
L
H
DESELECT or NOP
Self Refresh Exit
4, 5, 9, 16
Bank(s) Active
H
L
DESELECT or NOP
Active Power Down
Entry
4, 8, 10, 11,
13
All Banks Idle
H
L
DESELECT or NOP
Precharge Power Down
Entry
4, 8, 10, 11,
13
H
L
REFRESH
Self Refresh Entry
6, 9, 11, 13
H
H
Refer to the Command Truth Table
7
Notes:
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. All states and sequences not shown are illegal or reserved unless explicitly described elsewhere in this document.
5. 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.
6. Self Refresh mode can only be entered from the All Banks Idle state.
7. Must be a legal command as defined in the Command Truth Table.
8. Valid commands for Power Down Entry and Exit are NOP and DESELECT only.
9. Valid commands for Self Refresh Exit are NOP and DESELECT only.
10. Power Down and Self Refresh can not be entered while Read or Write operations, (Extended) Mode Register Set
operations or Precharge operations are in progress. See section 8.9 “Power Down Mode” and section 8.3.7/8.3.8 “Self
Refresh Entry Command/Self Refresh Exit Command” for a detailed list of restrictions.
11. tCKEmin of 3 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 3 clocks of registration. Thus, after any CKE transition, CKE may not
transition from its valid level during the time period of tIS + 2 x tCK + tIH.
12. The state of ODT does not affect the states described in this table. The ODT function is not available during Self Refresh.
See section 8.2.4.
13. The Power Down does not perform any refresh operations. The duration of Power Down Mode is therefore limited by the
refresh requirements outlined in section 8.9.
14. CKE must be maintained HIGH while the SDRAM is in OCD calibration mode.
15. “X” means “don’t care (including floating around VREF)” in Self Refresh and Power Down. However ODT must be driven
high or low in Power Down if the ODT function is enabled (Bit A2 or A6 set to “1” in EMR (1)).
16. VREF must be maintained during Self Refresh operation.
9.3 Data Mask (DM) Truth Table
FUNCTION
DM
DQS
NOTE
Write enable
L
Valid
1
Write inhibit
H
X
1
Note:
1. Used to mask write data, provided coincident with the corresponding data.
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9.4 Function Truth Table
CURRENT
STATE
CS
RAS
CAS
WE
ADDRESS
COMMAND
ACTION
NOTES
Idle
H
X
X
X
X
DSL
NOP or Power down
L
H
H
H
X
NOP
NOP or Power down
L
H
L
H
BA, CA, A10
READ/READA
ILLEGAL
1
L
H
L
L
BA, CA, A10
WRIT/WRITA
ILLEGAL
1
L
L
H
H
BA, RA
ACT
Row activating
L
L
H
L
BA, A10
PRE/PREA
Precharge/ Precharge all banks
L
L
L
H
X
REF/SELF
Auto Refresh or Self Refresh
2
L
L
L
L
Op-Code
MRS/EMRS
Mode/Extended register
accessing
2
Banks
Active
H
X
X
X
X
DSL
NOP
L
H
H
H
X
NOP
NOP
L
H
L
H
BA, CA, A10
READ/READA
Begin read
L
H
L
L
BA, CA, A10
WRIT/WRITA
Begin write
L
L
H
H
BA, RA
ACT
ILLEGAL
1
L
L
H
L
BA, A10
PRE/PREA
Precharge/ Precharge all banks
L
L
L
H
X
REF/SELF
ILLEGAL
L
L
L
L
Op-Code
MRS/EMRS
ILLEGAL
Read
H
X
X
X
X
DSL
Continue burst to end
L
H
H
H
X
NOP
Continue burst to end
L
H
L
H
BA, CA, A10
READ/READA
Burst interrupt
1, 3
L
H
L
L
BA, CA, A10
WRIT/WRITA
ILLEGAL
1
L
L
H
H
BA, RA
ACT
ILLEGAL
1
L
L
H
L
BA, A10
PRE/PREA
ILLEGAL
1
L
L
L
H
X
REF/SELF
ILLEGAL
L
L
L
L
Op-Code
MRS/EMRS
ILLEGAL
Write
H
X
X
X
X
DSL
Continue burst to end
L
H
H
H
X
NOP
Continue burst to end
L
H
L
H
BA, CA, A10
READ/READA
ILLEGAL
1
L
H
L
L
BA, CA, A10
WRIT/WRITA
Burst interrupt
1, 3
L
L
H
H
BA, RA
ACT
ILLEGAL
1
L
L
H
L
BA, A10
PRE/PREA
ILLEGAL
1
L
L
L
H
X
REF/SELF
ILLEGAL
L
L
L
L
Op-Code
MRS/EMRS
ILLEGAL
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Function Truth Table, continued
CURRENT
STATE
CS
RAS
CAS
WE
ADDRESS
COMMAND
ACTION
NOTES
Read with
Auto-
precharge
H
X
X
X
X
DSL
Continue burst to end
L
H
H
H
X
NOP
Continue burst to end
L
H
L
H
BA, CA, A10
READ/READA
ILLEGAL
1
L
H
L
L
BA, CA, A10
WRIT/WRITA
ILLEGAL
1
L
L
H
H
BA, RA
ACT
ILLEGAL
1
L
L
H
L
BA, A10
PRE/PREA
ILLEGAL
1
L
L
L
H
X
REF/SELF
ILLEGAL
L
L
L
L
Op-Code
MRS/EMRS
ILLEGAL
Write with
Auto-
precharge
H
X
X
X
X
DSL
Continue burst to end
L
H
H
H
X
NOP
Continue burst to end
L
H
L
H
BA, CA, A10
READ/READA
ILLEGAL
1
L
H
L
L
BA, CA, A10
WRIT/WRITA
ILLEGAL
1
L
L
H
H
BA, RA
ACT
ILLEGAL
1
L
L
H
L
BA, A10
PRE/PREA
ILLEGAL
1
L
L
L
H
X
REF/SELF
ILLEGAL
L
L
L
L
Op-Code
MRS/EMRS
ILLEGAL
Precharge
H
X
X
X
X
DSL
NOP-> Idle after tRP
L
H
H
H
X
NOP
NOP-> Idle after tRP
L
H
L
H
BA, CA, A10
READ/READA
ILLEGAL
1
L
H
L
L
BA, CA, A10
WRIT/WRITA
ILLEGAL
1
L
L
H
H
BA, RA
ACT
ILLEGAL
1
L
L
H
L
BA, A10
PRE/PREA
NOP-> Idle after tRP
1
L
L
L
H
X
REF/SELF
ILLEGAL
L
L
L
L
Op-Code
MRS/EMRS
ILLEGAL
Row
Activating
H
X
X
X
X
DSL
NOP-> Row active after tRCD
L
H
H
H
X
NOP
NOP-> Row active after tRCD
L
H
L
H
BA, CA, A10
READ/READA
ILLEGAL
1
L
H
L
L
BA, CA, A10
WRIT/WRITA
ILLEGAL
1
L
L
H
H
BA, RA
ACT
ILLEGAL
1
L
L
H
L
BA, A10
PRE/PREA
ILLEGAL
1
L
L
L
H
X
REF/SELF
ILLEGAL
L
L
L
L
Op-Code
MRS/EMRS
ILLEGAL
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Function Truth Table, continued
CURRENT
STATE
CS
RAS
CAS
WE
ADDRESS
COMMAND
ACTION
NOTES
Write
Recovering
H
X
X
X
X
DSL
NOP-> Bank active after tWR
L
H
H
H
X
NOP
NOP-> Bank active after tWR
L
H
L
H
BA, CA, A10
READ/READA
ILLEGAL
1
L
H
L
L
BA, CA, A10
WRIT/WRITA
New write
L
L
H
H
BA, RA
ACT
ILLEGAL
1
L
L
H
L
BA, A10
PRE/PREA
ILLEGAL
1
L
L
L
H
X
REF/SELF
ILLEGAL
L
L
L
L
Op-Code
MRS/EMRS
ILLEGAL
Write
Recovering
with Auto-
precharge
H
X
X
X
X
DSL
NOP-> Precharge after tWR
L
H
H
H
X
NOP
NOP-> Precharge after tWR
L
H
L
H
BA, CA, A10
READ/READA
ILLEGAL
1
L
H
L
L
BA, CA, A10
WRIT/WRITA
ILLEGAL
1
L
L
H
H
BA, RA
ACT
ILLEGAL
1
L
L
H
L
BA, A10
PRE/PREA
ILLEGAL
1
L
L
L
H
X
REF/SELF
ILLEGAL
L
L
L
L
Op-Code
MRS/EMRS
ILLEGAL
Refreshing
H
X
X
X
X
DSL
NOP-> Idle after tRC
L
H
H
H
X
NOP
NOP-> Idle after tRC
L
H
L
H
BA, CA, A10
READ/READA
ILLEGAL
L
H
L
L
BA, CA, A10
WRIT/WRITA
ILLEGAL
L
L
H
H
BA, RA
ACT
ILLEGAL
L
L
H
L
BA, A10
PRE/PREA
ILLEGAL
L
L
L
H
X
REF/SELF
ILLEGAL
L
L
L
L
Op-Code
MRS/EMRS
ILLEGAL
Mode
Register
Accessing
H
X
X
X
X
DSL
NOP-> Idle after tMRD
L
H
H
H
X
NOP
NOP-> Idle after tMRD
L
H
L
H
BA, CA, A10
READ/READA
ILLEGAL
L
H
L
L
BA, CA, A10
WRIT/WRITA
ILLEGAL
L
L
H
H
BA, RA
ACT
ILLEGAL
L
L
H
L
BA, A10
PRE/PREA
ILLEGAL
L
L
L
H
X
REF/SELF
ILLEGAL
L
L
L
L
Op-Code
MRS/EMRS
ILLEGAL
Notes:
1. This command may be issued for other banks, depending on the state of the banks.
2. All banks must be in “IDLE”.
3. Read or Write burst interruption is prohibited for burst length of 4 and only allowed for burst length of 8. Burst read/write can
only be interrupted by another read/write with 4 bit burst boundary. Any other case of read/write interrupt is not allowed.
Remark: H = High level, L = Low level, X = High or Low level (Don’t Care), V = Valid data.
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9.5 Simplified Stated Diagram
OCD
calibration
Initialization
Sequence
Self Refreshing
Refreshing
Precharge
Power
Down
Activating
Idle
All banks
Precharged
Setting
MR,EMR (1)
EMR (2)
EMR (3)
Active
Power
Down
Bank
Active
ReadingWriting
Writing
with
Auto-precharge
Precharging
Reading
with
Auto-precharge
(E)MRS REF
SELF
CKEH
CKEL
CKEH
ACT
PRE, PREA
Read
CKEL
CKEH
CKEL
Write
WRITA
WRITA READA
Write
READA
READA
CKEL
Autoomatic Sequence
Command Sequence
Read
CKEL
PRE
CKEL
Write Read
CKEL
PRE, PREAPRE, PREA
WRITA
CKEL = CKE LOW, enter Power Down
CKEH = CKE HIGH, exit Power Down
CKEH = CKE HIGH, exit Self Refresh
ACT = Activate
WRITA = Write with Auto-precharge
READA = Read with Auto-precharge
PRE = Precharge
PREA = Precharge All
(E)MRS = (Extended) Mode Register Set
SELF = Enter Self Refresh
REF = Refresh
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10. ELECTRICAL CHARACTERISTICS
10.1 Absolute Maximum Ratings
PARAMETER
SYMBOL
RATING
UNIT
NOTES
Voltage on VDD pin relative to VSS
VDD
-1.0 ~ 2.3
V
1, 2
Voltage on VDDQ pin relative to VSS
VDDQ
-0.5 ~ 2.3
V
1, 2
Voltage on VDDL pin relative to VSS
VDDL
-0.5 ~ 2.3
V
1, 2
Voltage on any pin relative to VSS
VIN, VOUT
-0.5 ~ 2.3
V
1, 2
Storage Temperature
TSTG
-55 ~ 150
°C
1, 3
Notes:
1. Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a
stress rating only and functional operation of the device at these or any other conditions above those indicated in the
operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended
periods may affect reliability.
2. When VDD and VDDQ and VDDL are less than 500mV; VREF may be equal to or less than 300mV.
3. Storage temperature is the case surface temperature on the center/top side of the DRAM.
10.2 Operating Temperature Condition
PARAMETER
SYMBOL
RATING
UNIT
NOTES
Operating Temperature (for -18/-25/-3)
TOPR
0 ~ 85
°C
1, 2, 3
Operating Temperature (for 25I)
TOPR
-40 ~ 95
°C
1, 2, 3, 4
Notes:
1. Operating Temperature is the case surface temperature on the center/top side of the DRAM.
2. Supporting 0 ~ 85°C with full JEDEC AC and DC specifications.
3. Supporting 0 ~ 85 °C and being able to extend to 95 °C with doubling Auto Refresh commands in frequency to a 32 mS
period ( tREFI = 3.9 µS) and to enter to Self Refresh mode at this high temperature range via A7 "1" on EMR (2).
4. During operation, the DRAM case temperature must be maintained between -40 to 95°C for Industrial parts under all
specification parameters.
10.3 Recommended DC Operating Conditions
SYM.
PARAMETER
MIN.
TYP.
MAX.
UNIT
NOTES
VDD
Supply Voltage
1.7
1.8
1.9
V
1
VDDL
Supply Voltage for DLL
1.7
1.8
1.9
V
5
VDDQ
Supply Voltage for Output
1.7
1.8
1.9
V
1, 5
VREF
Input Reference Voltage
0.49 x VDDQ
0.5 x VDDQ
0.51 x VDDQ
V
2, 3
VTT
Termination Voltage (System)
VREF - 0.04
VREF
VREF + 0.04
V
4
Notes:
1. There is no specific device VDD supply voltage requirement for SSTL_18 compliance. However under all conditions VDDQ
must than or equal to VDD.
2. The value of VREF may be selected by the user to provide optimum noise margin in the system. Typically the value of VREF
is expected to be about 0.5 x VDDQ of the transmitting device and VREF is expected to track variations in VDDQ.
3. Peak to peak AC noise on VREF may not exceed ± 2 % VREF(dc).
4. VTT of transmitting device must track VREF of receiving device.
5. VDDQ tracks with VDD, VDDL tracks with VDD. AC parameters are measured with VDD, VDDQ and VDDDL tied together.
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10.4 ODT DC Electrical Characteristics
PARAMETER/CONDITION
SYM.
MIN.
NOM.
MAX.
UNIT
NOTES
Rtt effective impedance value for EMRS(A6,A2)=0,1; 75 Ω
Rtt1(eff)
60
75
90
Ω
1
Rtt effective impedance value for EMRS(A6,A2)=1,0; 150 Ω
Rtt2(eff)
120
150
180
Ω
1
Rtt effective impedance value for EMRS(A6,A2)=1,1; 50 Ω
Rtt3(eff)
40
50
60
Ω
1, 2
Deviation of VM with respect to VDDQ/2
ΔVM
-6
+6
%
1
Notes:
1. Test condition for Rtt measurements.
2. Optional for DDR2-667, mandatory for DDR2-800 and DDR2-1066.
Measurement Definition for Rtt(eff):
Apply VIH (ac) and VIL (ac) to test pin separately, then measure current I(VIH (ac)) and I(VIL (ac))
respectively. VIH (ac), VIL (ac), and VDDQ values defined in SSTL_18.
Rtt(eff) = (VIH(ac) – VIL(ac)) /(I(VIHac) – I(VILac))
Measurement Definition for ΔVM:
Measure voltage (VM) at test pin (midpoint) with no load.
ΔVM = ((2 x Vm / VDDQ) – 1) x 100%
10.5 Input DC Logic Level
PARAMETER
SYM.
MIN.
MAX.
UNIT
DC input logic HIGH
VIH(dc)
VREF + 0.125
VDDQ + 0.3
V
DC input logic LOW
VIL(dc)
-0.3
VREF - 0.125
V
10.6 Input AC Logic Level
PARAMETER
SYM.
-18
-25/25I/-3
UNIT
MIN.
MAX.
MIN.
MAX.
AC input logic HIGH
VIH (ac)
VREF + 0.200
VREF + 0.200
VDDQ + VPEAK1
V
AC input logic LOW
VIL (ac)
VREF - 0.200
VSSQ - VPEAK1
VREF - 0.200
V
Note:
1. Refer to the page 67 sections 10.14.1 and 10.14.2 AC Overshoot/Undershoot specification table for VPEAK value: maximum
peak amplitude allowed for Overshoot/Undershoot.
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10.7 Capacitance
SYM.
PARAMETER
MIN.
MAX.
UNIT
CCK
Input Capacitance , CLK and
CLK
1.0
2.0
pF
CDCK
Input Capacitance delta , CLK and
CLK
0.25
pF
CI
input Capacitance, all other input-only pins
1.0
1.75
pF
CDI
Input Capacitance delta, all other input-only pins
0.25
pF
CIO
Input/output Capacitance, DQ, LDM, UDM, LDQS,
LDQS
, UDQS,
UDQS
2.5
3.5
pF
CDIO
Input/output Capacitance delta, DQ, LDM, UDM,
LDQS,
LDQS
, UDQS,
UDQS
0.5
pF
10.8 Leakage and Output Buffer Characteristics
SYM.
PARAMETER
MIN.
MAX.
UNIT
NOTES
IIL
Input Leakage Current
(0V ≤ VIN ≤ VDD)
-2
2
µA
1
IOL
Output Leakage Current
(Output disabled, 0V ≤ VOUT ≤ VDDQ)
-5
5
µA
2
VOTR
Output Timing Measurement Reference Level
0.5 x VDDQ
V
3
IOH(dc)
Output Minimum Source DC Current
-13.4
mA
4, 6
IOL(dc)
Output Minimum Sink DC Current
13.4
mA
5, 6
Notes:
1. All other pins not under test = 0 V.
2. DQ, LDQS,
LDQS
, UDQS,
UDQS
are disabled and ODT is turned off.
3. The VDDQ of the device under test is referenced.
4. VDDQ = 1.7 V; VOUT = 1.42 V. (VOUT - VDDQ)/IOH must be less than 21 Ω for values of VOUT between VDDQ and VDDQ -
0.28V.
5. VDDQ = 1.7 V; VOUT = 0.28V. VOUT/IOL must be less than 21 Ω for values of VOUT between 0 V and 0.28V.
6. The values of IOH(dc) and IOL(dc) are based on the conditions given in Notes 3 and 4. They are used to test drive current
capability to ensure VIHmin plus a noise margin and VILmax minus a noise margin are delivered to an SSTL_18 receiver.
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10.9 DC Characteristics
SYM.
CONDITIONS
-18
-25/25I
-3
UNIT
NOTES
MAX.
MAX.
MAX.
IDD0
Operating Current - One Bank Active-Precharge
tCK = tCK(IDD), tRC = tRC(IDD), tRAS = tRASmin(IDD);
CKE is HIGH,
CS
is HIGH between valid commands;
Address and control inputs are SWITCHING;
Data bus inputs are SWITCHING.
70
60
55
mA
1,2,3,4,5,
6
IDD1
Operating Current - One Bank Active-Read-
Precharge
IOUT = 0 mA;
BL = 4, CL = CL(IDD), AL = 0;
tCK = tCK(IDD), tRC = tRC(IDD), tRAS = tRASmin(IDD), tRCD
= tRCD(IDD);
CKE is HIGH,
CS
is HIGH between valid commands;
Address and control inputs are SWITCHING;
Data bus inputs are SWITCHING.
80
70
65
mA
1,2,3,4,5,
6
IDD2P
Precharge Power-Down Current
All banks idle;
tCK = tCK(IDD);
CKE is LOW;
Other control and address inputs are STABLE;
Data Bus inputs are FLOATING. (TCASE ≤ 85°C)
6
6
6
mA
1,2,3,4,5,
6,7
IDD2N
Precharge Standby Current
All banks idle;
tCK = tCK(IDD);
CKE is HIGH,
CS
is HIGH;
Other control and address inputs are SWITCHING;
Data bus inputs are SWITCHING.
45
40
35
mA
1,2,3,4,5,
6
IDD2Q
Precharge Quiet Standby Current
All banks idle;
tCK = tCK(IDD);
CKE is HIGH,
CS
is HIGH;
Other control and address inputs are STABLE;
Data bus inputs are FLOATING.
35
35
30
mA
1,2,3,4,5,
6
IDD3PF
Active Power-Down Current
All banks open;
tCK = tCK(IDD);
CKE is LOW;
Other control and address inputs are
STABLE;
Data bus inputs are FLOATING.
(TCASE ≤ 85°C)
Fast PDN Exit
MRS(12) = 0
15
15
15
mA
1,2,3,4,5,
6
IDD3PS
Slow PDN Exit
MRS(12) = 1
10
10
10
mA
1,2,3,4,5,
6,7
IDD3N
Active Standby Current
All banks open;
tCK = tCK(IDD); tRAS = tRASmax(IDD), tRP = tRP(IDD);
CKE is HIGH,
CS
is HIGH between valid commands;
Other control and address inputs are SWITCHING;
Data bus inputs are SWITCHING.
60
50
45
mA
1,2,3,4,5,
6
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IDD4R
Operating Burst Read Current
All banks open, Continuous burst reads, IOUT = 0 mA;
BL = 4, CL = CL(IDD), AL = 0;
tCK = tCK(IDD); tRAS = tRASmax(IDD), tRP = tRP(IDD);
CKE is HIGH,
CS
is HIGH between valid commands;
Address inputs are SWITCHING;
Data Bus inputs are SWITCHING.
125
105
95
mA
1,2,3,4,5,
6
IDD4W
Operating Burst Write Current
All banks open, Continuous burst writes;
BL = 4, CL = CL(IDD), AL = 0;
tCK = tCK(IDD); tRAS = tRASmax(IDD), tRP = tRP(IDD);
CKE is HIGH,
CS
is HIGH between valid commands;
Address inputs are SWITCHING;
Data Bus inputs are SWITCHING.
130
110
100
mA
1,2,3,4,5,
6
IDD5B
Burst Refresh Current
tCK = tCK(IDD);
Refresh command every tRFC(IDD) interval;
CKE is HIGH,
CS
is HIGH between valid commands;
Other control and address inputs are SWITCHING;
Data bus inputs are SWITCHING.
75
70
65
mA
1,2,3,4,5,
6
IDD6
Self Refresh Current
CKE ≤ 0.2 V, external clock off, CLK and
CLK
at 0 V;
Other control and address inputs are FLOATING;
Data bus inputs are FLOATING. (TCASE ≤ 85°C)
6
6
6
mA
1,2,3,4,5,
6,7
IDD7
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(IDD), tRRD = tRRD(IDD), tRCD =
tRCD(IDD);
CKE is HIGH,
CS
is HIGH between valid commands;
Address bus inputs are STABLE during deselects;
Data Bus inputs are SWITCHING.
160
135
115
mA
1,2,3,4,5,
6
Notes:
1. VDD = 1.8 V ± 0.1V; VDDQ = 1.8 V ± 0.1V.
2. IDD specifications are tested after the device is properly initialized.
3. Input slew rate is specified by AC Parametric Test Condition.
4. IDD parameters are specified with ODT disabled.
5. Data Bus consists of DQ, LDM, UDM, LDQS,
LDQS
, UDQS and
UDQS
.
6. Definitions for IDD
LOW = Vin ≤ VIL (ac) (max)
HIGH = Vin ≥ VIH (ac) (min)
STABLE = inputs stable at a HIGH or LOW level
FLOATING = inputs at VREF = VDDQ/2
SWITCHING = inputs changing between HIGH and LOW every other clock cycle (once per two clocks) for address and
control signals, and inputs changing between HIGH and LOW every other data transfer (once per clock)
for DQ signals not including masks or strobes.
7. The following IDD values must be derated (IDD limits increase), when TCASE ≥ 85°C 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 TCASE < 85°C
and the 2X refresh option is still enabled)
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
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10.10 IDD Measurement Test Parameters
SPEED GRADE
DDR2-1066
(-18)
DDR2-800
(-25/25I)
DDR2-667
(-3)
UNIT
Bin(CL-tRCD-tRP)
7-7-7
5-5-5/6-6-6
5-5-5
CL(IDD)
7
5/6
5
tCK
tCK(IDD)
1.875
2.5
3
nS
tRCD(IDD)
13.125
12.5
15
nS
tRP(IDD)
13.125
12.5
15
nS
tRC(IDD)
58.125
57.5
60
nS
tRASmin(IDD)
45
45
45
nS
tRASmax(IDD)
70000
70000
70000
nS
tRRD(IDD)-1KB
7.5
7.5
7.5
nS
tFAW(IDD)-1KB
35
35
37.5
nS
tRFC(IDD)
75
75
75
nS
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 43 -
10.11 AC Characteristics
10.11.1 AC Characteristics and Operating Condition for -18 speed grade
Notes: 1-3 and 45-47 apply to the entire table
SYM.
SPEED GRADE
DDR2-1066 (-18)
UNIT25
NOTES
Bin(CL-tRCD-tRP)
7-7-7
PARAMETER
MIN.
MAX.
tRCD
Active to Read/Write Command Delay Time
13.125
nS
23
tRP
Precharge to Active Command Period
13.125
nS
23
tRC
Active to Ref/Active Command Period
58.125
nS
23
tRAS
Active to Precharge Command Period
45
70000
nS
4,23
tRFC
Auto Refresh to Active/Auto Refresh command period
75
nS
5
tREFI
Average periodic
refresh Interval
0°C ≤ TCASE ≤ 85°C
7.8
μS
5
85°C < TCASE ≤ 95°C
3.9
μS
5,6
tCCD
CAS
to
CAS
command delay
2
nCK
tCK(avg)
Average clock period
tCK(avg) @ CL=4
3.75
7.5
nS
30,31
tCK(avg) @ CL=5
3
7.5
nS
30,31
tCK(avg) @ CL=6
2.5
7.5
nS
30,31
tCK(avg) @ CL=7
1.875
7.5
nS
30,31
tCH(avg)
Average clock high pulse width
0.48
0.52
tCK(avg)
30,31
tCL(avg)
Average clock low pulse width
0.48
0.52
tCK(avg)
30,31
tAC
DQ output access time from CLK/
CLK
-350
350
pS
35
tDQSCK
DQS output access time from CLK /
CLK
-325
325
pS
35
tDQSQ
DQS-DQ skew for DQS & associated DQ signals
175
pS
13
tCKE
CKE minimum high and low pulse width
3
nCK
7
tRRD
Active to active command period for 1KB page size
7.5
nS
8,23
tFAW
Four Activate Window for 1KB page size
35
nS
23
tWR
Write recovery time
15
nS
23
tDAL
Auto-precharge write recovery + precharge time
WR + tnRP
nCK
24
tWTR
Internal Write to Read command delay
7.5
nS
9,23
tRTP
Internal Read to Precharge command delay
7.5
nS
4,23
tIS (base)
Address and control input setup time
125
pS
10,26,
40,42,43
tIH (base)
Address and control input hold time
200
pS
11,26,
40,42,43
tIS (ref)
Address and control input setup time
325
pS
10,26,
40,42,43
tIH (ref)
Address and control input hold time
325
pS
11,26,
40,42,43
tIPW
Address and control input pulse width for each input
0.6
tCK(avg)
tDQSS
DQS latching rising transitions to associated clock edges
-0.25
0.25
tCK(avg)
28
tDSS
DQS falling edge to CLK setup time
0.2
tCK(avg)
28
tDSH
DQS falling edge hold time from CLK
0.2
tCK(avg)
28
tDQSH
DQS input high pulse width
0.35
tCK(avg)
tDQSL
DQS input low pulse width
0.35
tCK(avg)
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 44 -
AC Characteristics and Operating Condition for -18 speed grade, continued
Notes: 1-3 and 45-47 apply to the entire table
SYM.
SPEED GRADE
DDR2-1066 (-18)
UNITS25
NOTES
Bin(CL-tRCD-tRP)
7-7-7
PARAMETER
MIN.
MAX.
tWPRE
Write preamble
0.35
tCK(avg)
tWPST
Write postamble
0.4
0.6
tCK(avg)
12
tRPRE
Read preamble
0.9
1.1
tCK(avg)
14,36
tRPST
Read postamble
0.4
0.6
tCK(avg)
14,37
tDS(base)
DQ and DM input setup time
0
pS
16,27,29,
41,42,44
tDH(base)
DQ and DM input hold time
75
pS
17,27,29,
41,42,44
tDS(ref)
DQ and DM input setup time
200
pS
16,27,29,
41,42,44
tDH(ref)
DQ and DM input hold time
200
pS
17,27,29,
41,42,44
tDIPW
DQ and DM input pulse width for each input
0.35
tCK(avg)
tHZ
Data-out high-impedance time from CLK/
CLK
tAC,max
pS
15,35
tLZ(DQS)
DQS/
DQS
-low-impedance time from CLK/
CLK
tAC,min
tAC,max
pS
15,35
tLZ(DQ)
DQ low-impedance time from CLK/
CLK
2 x tAC,min
tAC,max
pS
15,35
tHP
Clock half pulse width
Min. (tCH(abs),
tCL(abs))
pS
32
tQHS
Data hold skew factor
250
pS
33
tQH
DQ/DQS output hold time from DQS
tHP - tQHS
pS
34
tXSNR
Exit Self Refresh to a non-Read command
tRFC + 10
nS
23
tXSRD
Exit Self Refresh to a Read command
200
nCK
tXP
Exit precharge power down to any command
3
nCK
tXARD
Exit active power down to Read command
3
nCK
18
tXARDS
Exit active power down to Read command
(slow exit, lower power)
10 - AL
nCK
18,19
tAOND
ODT turn-on delay
2
2
nCK
20
tAON
ODT turn-on
tAC,min
tAC,max + 2.575
nS
20,35
tAONPD
ODT turn-on (Power Down mode)
tAC,min + 2
3 x tCK(avg) +
tAC,max+1
nS
tAOFD
ODT turn-off delay
2.5
2.5
nCK
21,39
tAOF
ODT turn-off
tAC,min
tAC,max + 0.6
nS
21,38,39
tAOFPD
ODT turn-off (Power Down mode)
tAC,min + 2
2.5 x tCK(avg) +
tAC,max + 1
nS
tANPD
ODT to power down Entry Latency
4
nCK
tAXPD
ODT Power Down Exit Latency
11
nCK
tMRD
Mode Register Set command cycle time
2
nCK
tMOD
MRS command to ODT update delay
0
12
nS
23
tOIT
OCD Drive mode output delay
0
12
nS
23
tDELAY
Minimum time clocks remain ON after CKE
asynchronously drops LOW
tIS+tCK(avg)+tIH
nS
22
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 45 -
10.11.2 AC Characteristics and Operating Condition for -25/25I/-3 speed grade
Notes: 1-3 and 45-47 apply to the entire table
SYM.
SPEED GRADE
DDR2-800
(-25/25I)
DDR2-667
(-3)
UNITS25
NOTES
Bin(CL-tRCD-tRP)
5-5-5/6-6-6
5-5-5
PARAMETER
MIN.
MAX.
MIN.
MAX.
tRCD
Active to Read/Write Command Delay Time
12.5
15
nS
23
tRP
Precharge to Active Command Period
12.5
15
nS
23
tRC
Active to Ref/Active Command Period
57.5
60
nS
23
tRAS
Active to Precharge Command Period
45
70000
45
70000
nS
4,23
tRFC
Auto Refresh to Active/Auto Refresh command
period
75
75
nS
5
tREFI
Average periodic
refresh Interval
-40°C ≤ TCASE ≤ 85°C*
7.8
μS
5
0°C ≤ TCASE ≤ 85°C
7.8
7.8
μS
5
85°C < TCASE ≤ 95°C
3.9
3.9
μS
5,6
tCCD
CAS
to
CAS
command delay
2
2
nCK
tCK(avg)
Average clock period
tCK(avg) @ CL=3
5
8
5
8
nS
30,31
tCK(avg) @ CL=4
3.75
8
3.75
8
nS
30,31
tCK(avg) @ CL=5
2.5
8
3
8
nS
30,31
tCK(avg) @ CL=6
2.5
8
nS
30,31
tCH(avg)
Average clock high pulse width
0.48
0.52
0.48
0.52
tCK(avg)
30,31
tCL(avg)
Average clock low pulse width
0.48
0.52
0.48
0.52
tCK(avg)
30,31
tAC
DQ output access time from CLK/
CLK
-400
400
-450
450
pS
35
tDQSCK
DQS output access time from CLK /
CLK
-350
350
-400
400
pS
35
tDQSQ
DQS-DQ skew for DQS & associated DQ signals
200
240
pS
13
tCKE
CKE minimum high and low pulse width
3
3
nCK
7
tRRD
Active to active command period for 1KB page size
7.5
7.5
nS
8,23
tFAW
Four Activate Window for 1KB page size
35
37.5
nS
23
tWR
Write recovery time
15
15
nS
23
tDAL
Auto-precharge write recovery + precharge time
WR + tnRP
WR + tnRP
nCK
24
tWTR
Internal Write to Read command delay
7.5
7.5
nS
9,23
tRTP
Internal Read to Precharge command delay
7.5
7.5
nS
4,23
tIS (base)
Address and control input setup time
175
200
pS
10,26,
40,42,43
tIH (base)
Address and control input hold time
250
275
pS
11,26,
40,42,43
tIS (ref)
Address and control input setup time
375
400
pS
10,26,
40,42,43
tIH (ref)
Address and control input hold time
375
400
pS
11,26,
40,42,43
tIPW
Address and control input pulse width for each input
0.6
0.6
tCK(avg)
tDQSS
DQS latching rising transitions to associated clock
edges
-0.25
0.25
-0.25
0.25
tCK(avg)
28
tDSS
DQS falling edge to CLK setup time
0.2
0.2
tCK(avg)
28
tDSH
DQS falling edge hold time from CLK
0.2
0.2
tCK(avg)
28
tDQSH
DQS input high pulse width
0.35
0.35
tCK(avg)
tDQSL
DQS input low pulse width
0.35
0.35
tCK(avg)
* -40°C ≤ TCASE ≤ 85°C is for 25I grade only.
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 46 -
AC Characteristics and Operating Condition for -25/25I/-3 speed grades, continued
Notes: 1-3 and 45-47 apply to the entire table
SYM.
SPEED GRADE
DDR2-800
(-25/25I)
DDR2-667
(-3)
UNITS25
NOTES
Bin(CL-tRCD-tRP)
5-5-5/6-6-6
5-5-5
PARAMETER
MIN.
MAX.
MIN.
MAX.
tWPRE
Write preamble
0.35
0.35
tCK(avg)
tWPST
Write postamble
0.4
0.6
0.4
0.6
tCK(avg)
12
tRPRE
Read preamble
0.9
1.1
0.9
1.1
tCK(avg)
14,36
tRPST
Read postamble
0.4
0.6
0.4
0.6
tCK(avg)
14,37
tDS(base)
DQ and DM input setup time
50
100
pS
16,27,29,
41,42,44
tDH(base)
DQ and DM input hold time
125
175
pS
17,27,29,
41,42,44
tDS(ref)
DQ and DM input setup time
250
300
pS
16,27,29,
41,42,44
tDH(ref)
DQ and DM input hold time
250
300
pS
17,27,29,
41,42,44
tDIPW
DQ and DM input pulse width for each
input
0.35
0.35
tCK(avg)
tHZ
Data-out high-impedance time from CLK/
CLK
tAC,max
tAC,max
pS
15,35
tLZ(DQS)
DQS/
DQS
-low-impedance time from
CLK/
CLK
tAC,min
tAC,max
tAC,min
tAC,max
pS
15,35
tLZ(DQ)
DQ low-impedance time from CLK/
CLK
2 x tAC,min
tAC,max
2 x tAC,min
tAC,max
pS
15,35
tHP
Clock half pulse width
Min.
(tCH(abs),
tCL(abs))
Min.
(tCH(abs),
tCL(abs))
pS
32
tQHS
Data hold skew factor
300
340
pS
33
tQH
DQ/DQS output hold time from DQS
tHP - tQHS
tHP - tQHS
pS
34
tXSNR
Exit Self Refresh to a non-Read command
tRFC + 10
tRFC + 10
nS
23
tXSRD
Exit Self Refresh to a Read command
200
200
nCK
tXP
Exit precharge power down to any
command
2
2
nCK
tXARD
Exit active power down to Read command
2
2
nCK
18
tXARDS
Exit active power down to Read command
(slow exit, lower power)
8 - AL
7 - AL
nCK
18,19
tAOND
ODT turn-on delay
2
2
2
2
nCK
20
tAON
ODT turn-on
tAC,min
tAC,max + 0.7
tAC,min
tAC,max + 0.7
nS
20,35
tAONPD
ODT turn-on (Power Down mode)
tAC,min + 2
2 x tCK(avg) +
tAC,max + 1
tAC,min + 2
2 x tCK(avg) +
tAC,max + 1
nS
tAOFD
ODT turn-off delay
2.5
2.5
2.5
2.5
nCK
21,39
tAOF
ODT turn-off
tAC,min
tAC,max + 0.6
tAC,min
tAC,max + 0.6
nS
21,38,39
tAOFPD
ODT turn-off (Power Down mode)
tAC,min + 2
2.5 x tCK(avg)
+ tAC,max + 1
tAC,min + 2
2.5 x tCK(avg)
+ tAC,max + 1
nS
tANPD
ODT to power down Entry Latency
3
3
nCK
tAXPD
ODT Power Down Exit Latency
8
8
nCK
tMRD
Mode Register Set command cycle time
2
2
nCK
tMOD
MRS command to ODT update delay
0
12
0
12
nS
23
tOIT
OCD Drive mode output delay
0
12
0
12
nS
23
tDELAY
Minimum time clocks remain ON after
CKE asynchronously drops LOW
tIS+tCK(avg)+
tIH
tIS+tCK(avg)+
tIH
nS
22
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 47 -
Notes:
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 device operation are guaranteed for the full voltage range specified. ODT is
disabled for all measurements that are not ODT-specific.
3. AC timing reference load:
DQ
DQS, DQS Output
Timing
reference
point
VTT = VDDQ/2
25Ω
VDDQ
DUT
Figure 16 – AC timing reference load
4. This is a minimum requirement. Minimum read to precharge timing is AL + BL / 2 provided that the tRTP and tRAS(min)
have been satisfied.
5. If refresh timing is violated, data corruption may occur and the data must be re-written with valid data before a valid READ
can be executed.
6. This is an optional feature. For detailed information, please refer to “Operating Temperature Condition” section 10.2 in
this data sheet.
7. tCKE min of 3 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 3 clocks of registration. Thus, after any CKE transition, CKE may not
transition from its valid level during the time period of tIS + 2 x tCK + tIH.
8. A minimum of two clocks (2 * nCK) is required irrespective of operating frequency.
9. tWTR is at least two clocks (2 * nCK) independent of operation frequency.
10. There are two sets of values listed for Command/Address input setup time: tIS(base) and tIS(ref). The tIS(ref) value (for
reference only) is equivalent to the baseline value of tIS(base) at VREF when the slew rate is 1.0 V/nS. The baseline value
tIS(base) is the JEDEC defined value, 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. See Figure 17. If the Command/Address slew rate is not equal to
1.0 V/nS, then the baseline values must be derated by adding the values from table of tIS/tIH derating values for DDR2-667,
DDR2-800 and DDR2-1066 (page 55).
CLK
CLK tIS(base) tIH(base) tIS(base) tIH(base)
VDDQ
VIH(ac) min
VIH(dc) min
VREF(dc)
VIL(dc) max
VIL(ac) max
VSS
tIS(ref) tIH(ref) tIS(ref) tIH(ref)
Logic levels
VREF levels
Figure 17 – Differential input waveform timing – tIS and tIH
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 48 -
11. There are two sets of values listed for Command/Address input hold time: tIH(base) and tIH(ref). The tIH(ref) value (for
reference only) is equivalent to the baseline value of tIH(base) at VREF when the slew rate is 1.0 V/nS. The baseline value
tIH(base) is the JEDEC defined value, 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. See Figure 17. If the Command/Address slew rate is not equal to
1.0 V/nS, then the baseline values must be derated by adding the values from table tIS/tIH derating values for DDR2-667,
DDR2-800 and DDR2-1066 (page 55).
12. The maximum limit for the tWPST parameter is not a device limit. The device operates with a greater value for this
parameter, but system performance (bus turnaround) will degrades accordingly.
13. tDQSQ: Consists of data pin skew and output pattern effects, and p-channel to n-channel variation of the output drivers as
well as output Slew Rate mismatch between DQS /
DQS
and associated DQ in any given cycle.
14. tRPST end point and tRPRE begin point are not referenced to a specific voltage level but specify when the device output is
no longer driving (tRPST), or begins driving (tRPRE). Figure 18 shows a method to calculate these points when the device
is no longer driving (tRPST), or begins driving (tRPRE) by measuring the signal at two different voltages. The actual voltage
measurement points are not critical as long as the calculation is consistent.
15. tHZ and tLZ transitions occur in the same access time as valid data transitions. These parameters are referenced to a
specific voltage level which specifies when the device output is no longer driving (tHZ), or begins driving (tLZ). Figure 18
shows a method to calculate the point when device is no longer driving (tHZ), or begins driving (tLZ) by measuring the
signal at two different voltages. The actual voltage measurement points are not critical as long as the calculation is
consistent. tLZ(DQ) refers to tLZ of the DQ’s and tLZ(DQS) refers to tLZ of the (UDQS, LDQS,
UDQS
and
LDQS
) each
treated as single-ended signal.
VOH - x mV
VTT - 2x mV
VTT - x mV
VOH - 2x mV
VOL + 2x mV
VOL + x mV
VTT + x mV
VTT + 2x mV
tRPST end point tRPRE begin point
tHZ,tRPST end point = 2 x T1 - T2 tLZ,tRPRE begin point = 2 x T1 - T2
tHZ
T1 T2
tLZ
T1 T2
Figure 18 – Method for calculating transitions and endpoints
16. Input waveform timing tDS with differential data strobe enabled MR[bit10]=0. There are two sets of values listed for DQ and
DM input setup time: tDS(base) and tDS(ref). The tDS(ref) value (for reference only) is equivalent to the baseline value
tDS(base) at VREF when the slew rate is 2.0 V/nS, differentially. The baseline value tDS(base) is the JEDEC defined value,
referenced from the input signal crossing at the VIH(ac) level to the differential data strobe crosspoint for a rising signal, and
from the input signal crossing at the VIL(ac) level to the differential data strobe crosspoint for a falling signal applied to the
device under test. DQS,
DQS
signals must be monotonic between VIL(dc)max and VIH(dc)min. See Figure 19. If the
differential DQS slew rate is not equal to 2.0 V/nS, then the baseline values must be derated by adding the values from
table of DDR2-667, DDR2-800 and DDR2-1066 tDS/tDH derating with differential data strobe (page 60).
17. Input waveform timing tDH with differential data strobe enabled MR[bit10]=0. There are two sets of values listed for DQ and
DM input hold time: tDH(base) and tDH(ref). The tDH(ref) value (for reference only) is equivalent to the baseline value
tDH(base) at VREF when the slew rate is 2.0 V/nS, differentially. The baseline value tDH(base) is the JEDEC defined value,
referenced from the differential data strobe crosspoint to the input signal crossing at the VIH(dc) level for a falling signal and
from the differential data strobe crosspoint to the input signal crossing at the VIL(dc) level for a rising signal applied to the
device under test. DQS,
DQS
signals must be monotonic between VIL(dc)max and VIH(dc)min. See Figure 19. If the
differential DQS slew rate is not equal to 2.0 V/nS, then the baseline values must be derated by adding the values from
table of DDR2-667, DDR2-800 and DDR2-1066 tDS/tDH derating with differential data strobe (page 60).
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 49 -
DQS
DQS tDS(base) tDH(base) tDS(base) tDH(base)
VDDQ
VIH(ac) min
VIH(dc) min
VREF(dc)
VIL(dc) max
VIL(ac) max
VSS
tDS(ref) tDH(ref) tDS(ref) tDH(ref)
Logic levels
VREF levels
Figure 19 – Differential input waveform timing – tDS and tDH
18. User can choose which active power down exit timing to use via MRS (bit 12). tXARD is expected to be used for fast active
power down exit timing. tXARDS is expected to be used for slow active power down exit timing.
19. AL = Additive Latency.
20. ODT turn on time min is when the device leaves high impedance and ODT resistance begins to turn on. ODT turn on time
max is when the ODT resistance is fully on. Both are measure from tAOND, which is interpreted differently per speed bin.
For DDR2-667/800/1066, tAOND is 2 clock cycles after the clock edge that registered a first ODT HIGH counting the actual
input clock edges.
21. ODT turn off time min is when the device starts to turn off ODT resistance. ODT turn off time max is when the bus is in high
impedance. Both are measured from tAOFD, which is interpreted as 0.5 x tCK(avg) [nS] after the second trailing clock edge
counting from the clock edge that registered a first ODT LOW and by counting the actual input clock edges.
For DDR2-667/800: If tCK(avg) = 3 nS is assumed, tAOFD is 1.5 nS (= 0.5 x 3 nS) after the second trailing clock
edge counting from the clock edge that registered a first ODT LOW and by counting the actual input clock edges.
For DDR2-1066: tAOFD is 0.9375 [nS] (= 0.5 x 1.875 [nS]) after the second trailing clock edge counting from the
clock edge that registered a first ODT LOW and by counting the actual input clock edges.
22. The clock frequency is allowed to change during Self Refresh mode or precharge power-down mode. In case of clock
frequency change during precharge power-down, a specific procedure is required as described in section 8.10.
23. For these parameters, the DDR2 SDRAM device is characterized and verified to support tnPARAM = RU{tPARAM /
tCK(avg)}, which is in clock cycles, assuming all input clock jitter specifications are satisfied.
Examples:
The device will support tnRP = RU{tRP / tCK(avg)}, which is in clock cycles, if all input clock jitter specifications are
met. This means: For DDR2-667 5-5-5, of which tRP = 15nS, the device will support tnRP = RU{tRP / tCK(avg)} = 5,
i.e. as long as the input clock jitter specifications are met, Precharge command at Tm and Active command at Tm+5
is valid even if (Tm+5 - Tm) is less than 15nS due to input clock jitter. For DDR2-1066 7-7-7, of which tRP = 13.125
nS, the device will support tnRP = RU{tRP / tCK(avg)} = 7, i.e. as long as the input clock jitter specifications are met,
Precharge command at Tm and Active command at Tm+7 is valid even if (Tm+7 - Tm) is less than 13.125 nS due to
input clock jitter.
24. tDAL [nCK] = WR [nCK] + tnRP [nCK] = WR + RU {tRP [pS] / tCK(avg) [pS] }, where WR is the value programmed in the
mode register set and RU stands for round up.
Example:
For DDR2-1066 7-7-7 at tCK(avg) = 1.875 nS with WR programmed to 8 nCK, tDAL = 8 + RU{13.125 nS / 1.875
nS} [nCK] = 8 + 7 [nCK] = 15 [nCK].
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25. New units, ‘tCK(avg)’ and ‘nCK’, are introduced in DDR2-667, DDR2-800 and DDR2-1066.
Unit ‘tCK(avg)’ represents the actual tCK(avg) of the input clock under operation.
Unit ‘nCK’ represents one clock cycle of the input clock, counting the actual clock edges.
Examples:
For DDR2-667/800: tXP = 2 [nCK] means; if Power Down exit is registered at Tm, an Active command may be
registered at Tm+2, even if (Tm+2 - Tm) is 2 x tCK(avg) + tERR(2per),min.
For DDR2-1066: tXP = 3 [nCK] means; if Power Down exit is registered at Tm, an Active command may be
registered at Tm+3, even if (Tm+3 - Tm) is 3 x tCK(avg) + tERR(3per),min.
26. These parameters are measured from a command/address signal (CKE,
CS
,
RAS
,
CAS
,
WE
, ODT, BA0, A0, A1, etc.)
transition edge to its respective clock signal (CLK/
CLK
) crossing. The spec values are not affected by the amount of clock
jitter applied (i.e. tJIT(per), tJIT(cc), etc.), as the setup and hold are relative to the clock signal crossing that latches the
command/address. That is, these parameters should be met whether clock jitter is present or not.
27. If tDS or tDH is violated, data corruption may occur and the data must be re-written with valid data before a valid READ can
be executed.
28. These parameters are measured from a data strobe signal ((L/U)DQS/
DQS
) crossing to its respective clock signal (CLK/
CLK
) crossing. The spec values are not affected by the amount of clock jitter applied (i.e. tJIT(per), tJIT(cc), etc.), as these
are relative to the clock signal crossing. That is, these parameters should be met whether clock jitter is present or not.
29. These parameters are measured from a data signal ((L/U)DM, (L/U)DQ0, (L/U)DQ1, etc.) transition edge to its respective
data strobe signal ((L/U)DQS/
DQS
) crossing.
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30. Input clock jitter spec parameter. These parameters and the ones in the table below are referred to as 'input clock jitter spec
parameters'. The jitter specified is a random jitter meeting a Gaussian distribution.
Input clock-Jitter specifications parameters for DDR2-667, DDR2-800 and DDR2-1066
PARAMETER
SYMBOL
DDR2-667
DDR2-800
DDR2-1066
UNIT
MIN.
MAX.
MIN.
MAX.
MIN.
MAX.
Clock period jitter
tJIT(per)
-125
125
-100
100
-90
90
pS
Clock period jitter during DLL locking period
tJIT(per,lck)
-100
100
-80
80
-80
80
pS
Cycle to cycle clock period
tJIT(cc)
-250
250
-200
200
-180
180
pS
Cycle to cycle clock period jitter during DLL
locking period
tJIT(cc,lck)
-200
200
-160
160
-160
160
pS
Cumulative error across 2 cycles
tERR(2per)
-175
175
-150
150
-132
132
pS
Cumulative error across 3 cycles
tERR(3per)
-225
225
-175
175
-157
157
pS
Cumulative error across 4 cycles
tERR(4per)
-250
250
-200
200
-175
175
pS
Cumulative error across 5 cycles
tERR(5per)
-250
250
-200
200
-188
188
pS
Cumulative error across n cycles,
n = 6 ... 10, inclusive
tERR(6-10per)
-350
350
-300
300
-250
250
pS
Cumulative error across n cycles,
n = 11 ... 50, inclusive
tERR(11-50per)
-450
450
-450
450
-425
425
pS
Duty cycle jitter
tJIT(duty)
-125
125
-100
100
-75
75
pS
Definitions:
- tCK(avg)
tCK(avg) is calculated as the average clock period across any consecutive 200 cycle window.
tCK(avg) =
N
jj
tCK
1
/ N
where N = 200
- tCH(avg) and tCL(avg)
tCH(avg) is defined as the average HIGH pulse width, as calculated across any consecutive 200 HIGH pulses.
tCH(avg) =
N
jj
tCH
1
/ (N × tCK(avg))
where N = 200
tCL(avg) is defined as the average LOW pulse width, as calculated across any consecutive 200 LOW pulses.
tCL(avg) =
N
jj
tCL
1
/ (N × tCK(avg))
where N = 200
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- tJIT(duty)
tJIT(duty) is defined as the cumulative set of tCH jitter and tCL jitter. tCH jitter is the largest deviation of any single tCH from
tCH(avg). tCL jitter is the largest deviation of any single tCL from tCL(avg).
tJIT(duty) = Min/max of {tJIT(CH), tJIT(CL)}
where,
tJIT(CH) = {tCHi- tCH(avg) where i=1 to 200}
tJIT(CL) = {tCLi- tCL(avg) where i=1 to 200}
- tJIT(per), tJIT(per,lck)
tJIT(per) is defined as the largest deviation of any single tCK from tCK(avg).
tJIT(per) = Min/max of {tCKi- tCK(avg) where i=1 to 200}
tJIT(per) defines the single period jitter when the DLL is already locked.
tJIT(per,lck) uses the same definition for single period jitter, during the DLL locking period only.
tJIT(per) and tJIT(per,lck) are not guaranteed through final production testing.
- tJIT(cc), tJIT(cc,lck)
tJIT(cc) is defined as the difference in clock period between two consecutive clock cycles:
tJIT(cc) = Max of |tCKi+1 – tCKi|
tJIT(cc) defines the cycle to cycle jitter when the DLL is already locked.
tJIT(cc,lck) uses the same definition for cycle to cycle jitter, during the DLL locking period only.
tJIT(cc) and tJIT(cc,lck) are not guaranteed through final production testing.
- tERR(2per), tERR (3per), tERR (4per), tERR (5per), tERR (6-10per) and tERR (11-50per)
tERR is defined as the cumulative error across multiple consecutive cycles from tCK(avg).
tERR(nper) =
1
1
ni
jj
tCK
–n × tCK(avg)
Where
50per)–R(11for tER 50 n 11
10per)–R(6for tER 10 n 6
R(5per)for tER 5 =n
R(4per)for tER 4 =n
R(3per)for tER 3 =n
R(2per)for tER 2 =n
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31. These parameters are specified per their average values, however it is understood that the following relationship between
the average timing and the absolute instantaneous timing holds at all times. (Min and max of SPEC values are to be used
for calculations in the table below.)
PARAMETER
SYMBOL
MIN
MAX
UNIT
Absolute clock period
tCK(abs)
tCK(avg),min + tJIT(per),min
tCK(avg),max + tJIT(per),max
pS
Absolute clock HIGH pulse width
tCH(abs)
tCH(avg),min x tCK(avg),min +
tJIT(duty),min
tCH(avg),max x tCK(avg),max +
tJIT(duty),max
pS
Absolute clock LOW pulse width
tCL(abs)
tCL(avg),min x tCK(avg),min +
tJIT(duty),min
tCL(avg),max x tCK(avg),max +
tJIT(duty),max
pS
Examples: 1) For DDR2-667, tCH(abs),min = ( 0.48 x 3000 pS ) - 125 pS = 1315 pS
2) For DDR2-1066, tCH(abs),min = ( 0.48 x 1875 pS ) - 75 pS = 825 pS
32. tHP is the minimum of the absolute half period of the actual input clock. tHP is an input parameter but not an input
specification parameter. It is used in conjunction with tQHS to derive the DRAM output timing tQH. The value to be used for
tQH calculation is determined by the following equation;
tHP = Min ( tCH(abs), tCL(abs) ),
where,
tCH(abs) is the minimum of the actual instantaneous clock HIGH time;
tCL(abs) is the minimum of the actual instantaneous clock LOW time;
33. tQHS accounts for:
1) The pulse duration distortion of on-chip clock circuits, which represents how well the actual tHP at the input is
transferred to the output; and
2) The worst case push-out of DQS on one transition followed by the worst case pull-in of DQ on the next transition,
both of which are independent of each other, due to data pin skew, output pattern effects, and p-channel to n-
channel variation of the output drivers
34. tQH = tHP – tQHS, where:
tHP is the minimum of the absolute half period of the actual input clock; and
tQHS is the specification value under the max column.
{The less half-pulse width distortion present, the larger the tQH value is; and the larger the valid data eye will be.}
Examples:
1) If the system provides tHP of 1315 pS into a DDR2-667 SDRAM, the DRAM provides tQH of 975 pS minimum.
2) If the system provides tHP of 1420 pS into a DDR2-667 SDRAM, the DRAM provides tQH of 1080 pS minimum.
3) If the system provides tHP of 825 pS into a DDR2-1066 SDRAM, the DRAM provides tQH of 575 pS minimum.
4) If the system provides tHP of 900 pS into a DDR2-1066 SDRAM, the DRAM provides tQH of 650 pS minimum.
35. When the device is operated with input clock jitter, this parameter needs to be derated by the actual tERR(6-10per) of the
input clock. (output deratings are relative to the SDRAM input clock.)
Examples:
1) If the measured jitter into a DDR2-667 SDRAM has tERR(6-10per),min = - 272 pS and tERR(6-10per),max = +
293 pS, then tDQSCK,min(derated) = tDQSCK,min - tERR(6-10per),max = - 400 pS - 293 pS = - 693 pS and
tDQSCK,max(derated) = tDQSCK,max - tERR(6-10per),min = 400 pS + 272 pS = + 672 pS.
Similarly, tLZ(DQ) for DDR2-667 derates to tLZ(DQ),min(derated) = - 900 pS - 293 pS = - 1193 pS and
tLZ(DQ),max(derated) = 450 pS + 272 pS = + 722 pS. (Caution on the min/max usage!)
2) If the measured jitter into a DDR2-1066 SDRAM has tERR(6-10per),min = - 202 pS and tERR(6-10per),max = +
223 pS, then tDQSCK,min(derated) = tDQSCK,min - tERR(6-10per),max = - 300 pS - 223 pS = - 523 pS and
tDQSCK,max(derated) = tDQSCK,max - tERR(6-10per),min = 300 pS + 202 pS = + 502 pS.
Similarly, tLZ(DQ) for DDR2-1066 derates to tLZ(DQ),min(derated) = - 700 pS - 223 pS = - 923 pS and
tLZ(DQ),max(derated) = 350 pS + 202 pS = + 552 pS. (Caution on the min/max usage!)
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36. When the device is operated with input clock jitter, this parameter needs to be derated by the actual tJIT(per) of the input
clock. (output deratings are relative to the SDRAM input clock.)
Examples:
1) If the measured jitter into a DDR2-667 SDRAM has tJIT(per),min = - 72 pS and tJIT(per),max = + 93 pS, then
tRPRE,min(derated) = tRPRE,min + tJIT(per),min = 0.9 x tCK(avg) - 72 pS = + 2178 pS and tRPRE,max(derated) =
tRPRE,max + tJIT(per),max = 1.1 x tCK(avg) + 93 pS = + 2843 pS. (Caution on the min/max usage!)
2) If the measured jitter into a DDR2-1066 SDRAM has tJIT(per),min = - 72 pS and tJIT(per),max = + 63 pS, then
tRPRE,min(derated) = tRPRE,min + tJIT(per),min = 0.9 x tCK(avg) - 72 pS = + 1615.5 pS and tRPRE,max(derated)
= tRPRE,max + tJIT(per),max = 1.1 x tCK(avg) + 63 pS = + 2125.5 pS. (Caution on the min/max usage!)
37. When the device is operated with input clock jitter, this parameter needs to be derated by the actual tJIT(duty) of the input
clock. (output deratings are relative to the SDRAM input clock.)
Examples:
1) If the measured jitter into a DDR2-800 SDRAM has tJIT(duty),min = - 72 pS and tJIT(duty),max = + 93 pS, then
tRPST,min(derated) = tRPST,min + tJIT(duty),min = 0.4 x tCK(avg) - 72 pS = + 928 pS and tRPST,max(derated) =
tRPST,max + tJIT(duty),max = 0.6 x tCK(avg) + 93 pS = + 1593 pS. (Caution on the min/max usage!)
2) If the measured jitter into a DDR2-1066 SDRAM has tJIT(duty),min = - 72 pS and tJIT(duty),max = + 63 pS, then
tRPST,min(derated) = tRPST,min + tJIT(duty),min = 0.4 x tCK(avg) - 72 pS = + 678 pS and tRPST,max(derated) =
tRPST,max + tJIT(duty),max = 0.6 x tCK(avg) + 63 pS = + 1188 pS. (Caution on the min/max usage!)
38. When the device is operated with input clock jitter, this parameter needs to be derated by { -tJIT(duty),max - tERR(6-
10per),max } and { - tJIT(duty),min - tERR(6-10per),min } of the actual input clock. (output deratings are relative to the
SDRAM input clock.)
Examples:
1) If the measured jitter into a DDR2-667 SDRAM has tERR(6-10per),min = - 272 pS, tERR(6-10per),max = + 293
pS, tJIT(duty),min = - 106 pS and tJIT(duty),max = + 94 pS, then tAOF,min(derated) = tAOF,min + { - tJIT(duty),max
- tERR(6-10per),max } = - 450 pS + { - 94 pS - 293 pS} = - 837 pS and tAOF,max(derated) = tAOF,max + { -
tJIT(duty),min - tERR(6-10per),min } = 1050 pS + { 106 pS + 272 pS } = + 1428 pS. (Caution on the min/max
usage!)
2) If the measured jitter into a DDR2-1066 SDRAM has tERR(6-10per),min = - 202 pS, tERR(6-10per),max = + 223
pS, tJIT(duty),min = - 66 pS and tJIT(duty),max = + 74 pS, then tAOF,min(derated) = tAOF,min + { - tJIT(duty),max -
tERR(6-10per),max } = - 350 pS + { - 74 pS - 223 pS} = - 647 pS and tAOF,max(derated) = tAOF,max + { -
tJIT(duty),min - tERR(6-10per),min } = 950 pS + { 66 pS + 202 pS } = + 1218 pS. (Caution on the min/max usage!)
39. For tAOFD of DDR2-667/800/1066, the 1/2 clock of nCK in the 2.5 x nCK assumes a tCH(avg), average input clock HIGH
pulse width of 0.5 relative to tCK(avg). tAOF,min and tAOF,max should each be derated by the same amount as the actual
amount of tCH(avg) offset present at the DRAM input with respect to 0.5.
Example:
If an input clock has a worst case tCH(avg) of 0.48, the tAOF,min should be derated by subtracting 0.02 x tCK(avg)
from it, whereas if an input clock has a worst case tCH(avg) of 0.52, the tAOF,max should be derated by adding
0.02 x tCK(avg) to it. Therefore, we have;
tAOF,min(derated) = tAC,min - [0.5 - Min(0.5, tCH(avg),min)] x tCK(avg)
tAOF,max(derated) = tAC,max + 0.6 + [Max(0.5, tCH(avg),max) - 0.5] x tCK(avg)
or
tAOF,min(derated) = Min(tAC,min, tAC,min - [0.5 - tCH(avg),min] x tCK(avg))
tAOF,max(derated) = 0.6 + Max(tAC,max, tAC,max + [tCH(avg),max - 0.5] x tCK(avg))
where tCH(avg),min and tCH(avg),max are the minimum and maximum of tCH(avg) actually measured at the
DRAM input balls.
Note that these deratings are in addition to the tAOF derating per input clock jitter, i.e. tJIT(duty) and tERR(6-10per). However
tAC values used in the equations shown above are from the timing parameter table and are not derated.
Thus the final derated values for tAOF are;
tAOF,min(derated_final) = tAOF,min(derated) + { - tJIT(duty),max - tERR(6-10per),max }
tAOF,max(derated_final) = tAOF,max(derated) + { - tJIT(duty),min - tERR(6-10per),min }
40. Timings are specified with command/address input slew rate of 1.0 V/nS.
41. Timings are specified with DQs and DM input slew rate of 1.0V/nS.
42. Timings are specified with CLK/
CLK
differential slew rate of 2.0 V/nS. Timings are guaranteed for DQS signals with a
differential slew rate of 2.0 V/nS in differential strobe mode.
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43. tIS and tIH (input setup and hold) derating.
tIS/tIH Derating values for DDR2-667, DDR2-800 and DDR2-1066
Command/
Address
Slew Rate
(V/nS)
ΔtIS and ΔtIH Derating Values for DDR2-667, DDR2-800 and DDR2-1066
CLK/
CLK
Differential Slew Rate
2.0 V/nS
1.5 V/nS
1.0 V/nS
Unit
ΔtIS
ΔtIH
ΔtIS
ΔtIH
ΔtIS
ΔtIH
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
+130
+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
+26
-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
For all input signals the total tIS (setup time) and tIH (hold time) required is calculated by adding the data sheet tIS(base) and
tIH(base) value to the ΔtIS and ΔtIH derating value respectively. Example: tIS (total setup time) = tIS(base) + ΔtIS.
Setup (tIS) nominal slew rate for a rising signal is defined as the slew rate between the last crossing of VREF(dc) and the first
crossing of VIH(ac)min. Setup (tIS) 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
shaded ‘VREF(dc) to AC region’, use nominal slew rate for derating value. See Figure 20 Illustration of nominal slew rate for tIS.
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 derating value. See Figure 21 Illustration of tangent line
for tIS.
Hold (tIH) 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). Hold (tIH) nominal slew rate for a falling signal is defined as the slew rate between the last crossing of
VIH(dc)min and the first crossing of VREF(dc). If the actual signal is always later than the nominal slew rate line between
shaded ‘DC to VREF(dc) region’, use nominal slew rate for derating value. See Figure 22 Illustration of nominal slew rate for tIH.
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 derating value. See Figure 23 Illustration of
tangent line for tIH.
Although for slow slew rates the total setup time might be negative (i.e. a valid input signal will not have reached VIH/IL(ac) at
the time of the rising clock transition) a valid input signal is still required to complete the transition and reach VIH/IL(ac).
For slew rates in between the values listed in above tIS/tIH derating values for DDR2-667, DDR2-800 and DDR2-1066 table, the
derating values may obtained by linear interpolation.
These values are typically not subject to production test. They are verified by design and characterization.
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CLK
CLK
tIS tIH tIS tIH
nominal
slew rate
nominal
slew rate
VREF to AC
region
VDDQ
VIH(ac)min
VIH(dc)min
VREF(dc)
VIL(dc)max
VIL(ac)max
VSS
ΔTF ΔTR
Setup Slew Rate
Falling Signal =VREF(dc) - VIL(ac)max Setup Slew Rate
Rising Signal =VIH(ac)min - VREF(dc)
VREF to AC
region
ΔTF ΔTR
Figure 20 – Illustration of nominal slew rate for tIS
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tIS tIH tIS tIH
tangent
line
tangent
line
VREF to AC
region
VDDQ
VIH(ac)min
VIH(dc)min
VREF(dc)
VIL(dc)max
VIL(ac)max
VSS
ΔTF
ΔTR
Setup Slew Rate
Falling Signal =tangent line[VREF(dc) - VIL(ac)max]
VREF to AC
region
nominal
line
Setup Slew Rate
Rising Signal =tangent line[VIH(ac)min - VREF(dc)]
nominal
line
CLK
CLK
ΔTR
ΔTF
Figure 21 – Illustration of tangent line for tIS
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tIS tIH tIS tIH
nominal
slew rate
nominal
slew rate
DC to VREF
region
VDDQ
VIH(ac)min
VIH(dc)min
VREF(dc)
VIL(dc)max
VIL(ac)max
VSS
ΔTF
ΔTR
Hold Slew Rate
Rising Signal =VREF(dc) - VIL(dc)max Hold Slew Rate
Falling Signal =VIH(dc)min - VREF(dc)
DC to VREF
region
CLK
CLK
ΔTR ΔTF
Figure 22 – Illustration of nominal slew rate for tIH
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tIS tIH tIS tIH
tangent
line
DC to VREF
region
VDDQ
VIH(ac)min
VIH(dc)min
VREF(dc)
VIL(dc)max
VIL(ac)max
VSS
ΔTFΔTR
DC to VREF
region
nominal
line
tangent
line
nominal
line
Hold Slew Rate
Rising Signal =tangent line[VREF(dc) - VIL(dc)max]
Hold Slew Rate
Falling Signal =tangent line[VIH(dc)min - VREF(dc)]
CLK
CLK
ΔTR
ΔTF
Figure 23 – Illustration of tangent line for tIH
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44. Data setup and hold time derating.
DDR2-667, DDR2-800 and DDR2-1066 tDS/tDH derating with differential data strobe
DQ
Slew
Rate
(V/nS)
ΔtDS, ΔtDH Derating Values for DDR2-667, DDR2-800 and DDR2-1066 (All units in ‘pS’; the note applies to
the entire table)
DQS/
DQS
Differential Slew Rate
4.0 V/nS
3.0 V/nS
2.0 V/nS
1.8 V/nS
1.6 V/nS
1.4 V/nS
1.2 V/nS
1.0 V/nS
0.8 V/nS
ΔtDS
ΔtDH
ΔtDS
ΔtDH
ΔtDS
ΔtDH
ΔtDS
ΔtDH
ΔtDS
ΔtDH
ΔtDS
ΔtDH
ΔtDS
ΔtDH
ΔtDS
ΔtDH
ΔtDS
ΔtDH
2.0
100
45
100
45
100
45
-
-
-
-
-
-
-
-
-
-
-
-
1.5
67
21
67
21
67
21
79
33
-
-
-
-
-
-
-
-
-
-
1.0
0
0
0
0
0
0
12
12
24
24
-
-
-
-
-
-
-
-
0.9
-
-
-5
-14
-5
-14
7
-2
19
10
31
22
-
-
-
-
-
-
0.8
-
-
-
-
-13
-31
-1
-19
11
-7
23
5
35
17
-
-
-
-
0.7
-
-
-
-
-
-
-10
-42
2
-30
14
-18
26
-6
38
6
-
-
0.6
-
-
-
-
-
-
-
-
-10
-59
2
-47
14
-35
26
-23
38
-11
0.5
-
-
-
-
-
-
-
-
-
-
-24
-89
-12
-77
0
-65
12
-53
0.4
-
-
-
-
-
-
-
-
-
-
-
-
-52
-140
-40
-128
-28
-116
For all input signals the total tDS (setup time) and tDH (hold time) required is calculated by adding the data sheet tDS(base) and
tDH(base) value to the ΔtDS and ΔtDH derating value respectively. Example: tDS (total setup time) = tDS(base) + ΔtDS.
Setup (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. Setup (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
shaded ‘VREF(dc) to AC region’, use nominal slew rate for derating value. See Figure 24 Illustration of nominal slew rate for
tDS (differential DQS,
DQS
).
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 derating value. See Figure 25 Illustration of tangent line
for tDS (differential DQS,
DQS
).
Hold (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). Hold (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
shaded ‘DC level to VREF(dc) region’, use nominal slew rate for derating value. See Figure 26 Illustration of nominal slew rate
for tDH (differential DQS,
DQS
).
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 derating value. See Figure 27 Illustration of
tangent line for tDH (differential DQS,
DQS
).
Although for slow slew rates the total setup time might be negative (i.e. a valid input signal will not have reached VIH/IL(ac) at
the time of the rising clock transition) a valid input signal is still required to complete the transition and reach VIH/IL(ac).
For slew rates in between the values listed in above DDR2-667, DDR2-800 and DDR2-1066 tDS/tDH derating with differential
data strobe table, the derating values may be obtained by linear interpolation.
These values are typically not subject to production test. They are verified by design and characterization.
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45. Slew Rate Measurement Levels:
a) Output slew rate for falling and rising edges is measured between VTT - 250 mV and VTT + 250 mV for single ended
signals.
For differential signals (e.g. DQS -
DQS
) output slew rate is measured between DQS -
DQS
= - 500 mV and DQS -
DQS
= + 500 mV. Output slew rate is guaranteed by design, but is not necessarily tested on each device.
b) Input slew rate for single ended signals is measured from VREF(dc) to VIH(ac),min for rising edges and from VREF(dc) to
VIL(ac),max for falling edges.
For differential signals (e.g. CLK -
CLK
) slew rate for rising edges is measured from CLK -
CLK
= - 250 mV to CLK -
CLK
= + 500 mV (+ 250 mV to - 500 mV for falling edges).
c) VID is the magnitude of the difference between the input voltage on CLK and the input voltage on
CLK
, or between DQS
and
DQS
for differential strobe.
46. DDR2 SDRAM output slew rate test load:
Output slew rate is characterized under the test conditions as shown in below figure.
DQ
DQS, DQS Output
Test point
VTT = VDDQ/2
25Ω
VDDQ
DUT
Output slew rate test load
47. Differential data strobe:
DDR2 SDRAM pin timings are specified for either single ended mode or differential mode depending on the setting of the
EMRS “Enable DQS” mode bit; timing advantages of differential mode are realized in system design. The method by which
the DDR2 SDRAM pin timings are measured is mode dependent. In single ended mode, timing relationships are measured
relative to the rising or falling edges of DQS crossing at VREF. In differential mode, these timing relationships are measured
relative to the cross point of DQS and its complement,
DQS
. This distinction in timing methods is guaranteed by design
and characterization. Note that when differential data strobe mode is disabled via the EMRS, the complementary pin,
DQS
,
must be tied externally to VSS through a 20 Ω to 10 kΩ resistor to insure proper operation.
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tDS tDH tDS tDH
nominal
slew rate
nominal
slew rate
VREF to AC
region
VDDQ
VIH(ac)min
VIH(dc)min
VREF(dc)
VIL(dc)max
VIL(ac)max
VSS
ΔTF ΔTR
Setup Slew Rate
Falling Signal =VREF(dc) - VIL(ac)max Setup Slew Rate
Rising Signal =VIH(ac)min - VREF(dc)
VREF to AC
region
DQS
DQS
ΔTR
ΔTF
Figure 24 – Illustration of nominal slew rate for tDS (differential DQS,
DQS
)
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DQS
DQS
tDS tDH tDS tDH
tangent
line
tangent
line
VREF to AC
region
VDDQ
VIH(ac)min
VIH(dc)min
VREF(dc)
VIL(dc)max
VIL(ac)max
VSS
ΔTF
ΔTR
Setup Slew Rate
Falling Signal =tangent line[VREF(dc) - VIL(ac)max]
VREF to AC
region
nominal
line
Setup Slew Rate
Rising Signal =tangent line[VIH(ac)min - VREF(dc)]
nominal
line
ΔTF
ΔTR
Figure 25 – Illustration of tangent line for tDS (differential DQS,
DQS
)
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DQS
DQS
tDS tDH tDS tDH
nominal
slew rate
nominal
slew rate
DC to VREF
region
VDDQ
VIH(ac)min
VIH(dc)min
VREF(dc)
VIL(dc)max
VIL(ac)max
VSS
ΔTFΔTR
Hold Slew Rate
Rising Signal =VREF(dc) - VIL(dc)max Hold Slew Rate
Falling Signal =VIH(dc)min - VREF(dc)
DC to VREF
region
ΔTR ΔTF
Figure 26 – Illustration of nominal slew rate for tDH (differential DQS,
DQS
)
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DQS
DQS
tDS tDH tDS tDH
tangent
line
DC to VREF
region
VDDQ
VIH(ac)min
VIH(dc)min
VREF(dc)
VIL(dc)max
VIL(ac)max
VSS
ΔTFΔTR
DC to VREF
region
nominal
line
tangent
line
nominal
line
Hold Slew Rate
Rising Signal =tangent line[VREF(dc) - VIL(dc)max]
Hold Slew Rate
Falling Signal =tangent line [VIH(dc)min - VREF(dc)]
ΔTF
ΔTR
Figure 27 – Illustration tangent line for tDH (differential DQS,
DQS
)
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10.12 AC Input Test Conditions
CONDITION
SYMBOL
VALUE
UNIT
NOTES
Input reference voltage
VREF
0.5 x VDDQ
V
1
Input signal maximum peak to peak swing
VSWING(MAX)
1.0
V
1
Input signal minimum slew rate
SLEW
1.0
V/nS
2, 3
Notes:
1. Input waveform timing is referenced to the input signal crossing through the VIH/IL(ac) level applied to the device under test.
2. The input signal minimum slew rate is to be maintained over the range from VREF to VIH(ac) min for rising edges and the
range from VREF to VIL(ac) max for falling edges as shown in the below figure.
3. AC timings are referenced with input waveforms switching from VIL(ac) to VIH(ac) on the positive transitions and VIH(ac) to
VIL(ac) on the negative transitions.
10.13 Differential Input/Output AC Logic Levels
PARAMETER
SYM.
MIN.
MAX.
UNIT
NOTES
AC differential input voltage
VID (ac)
0.5
VDDQ + 0.6
V
1
AC differential cross point input voltage
VIX (ac)
0.5 x VDDQ - 0.175
0.5 x VDDQ + 0.175
V
2
AC differential cross point output voltage
VOX (ac)
0.5 x VDDQ - 0.125
0.5 x VDDQ + 0.125
V
3
Notes:
1. VID (ac) specifies the input differential voltage |VTR -VCP | required for switching, where VTR is the true input signal (such
as CLK, LDQS or UDQS) and VCP is the complementary input signal (such as
CLK
,
LDQS
or
UDQS
). The minimum
value is equal to VIH (ac) - VIL (ac).
2. The typical value of VIX (ac) is expected to be about 0.5 x 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.
3. The typical value of VOX (ac) is expected to be about 0.5 x 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.
ΔTF ΔTR
VDDQ
VIH(ac) min
Falling Slew = Rising Slew =
VIH(dc) min
VREF
VIL(dc) max
VIL(ac) max
VSS
VSWING(MAX)
VREF - VIL(ac) max
ΔTF VIH(ac) min - VREF
ΔTR
VDDQ
VSSQ
VIX or VOX
VID
VTR Crossing point
VCP
Figure 28 – AC input test signal and Differential signal levels waveform
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10.14 AC Overshoot / Undershoot Specification
10.14.1 AC Overshoot / Undershoot Specification for Address and Control Pins:
Applies to A0-A12, BA0-BA1,
CS
,
RAS
,
CAS
,
WE
, CKE, ODT
PARAMETER
DDR2-1066
DDR2-800
DDR2-667
UNIT
Maximum peak amplitude allowed for overshoot area
0.5
0.5
0.5
V
Maximum peak amplitude allowed for undershoot area
0.5
0.5
0.5
V
Maximum overshoot area above VDD
0.5
0.66
0.8
V-nS
Maximum undershoot area below VSS
0.5
0.66
0.8
V-nS
10.14.2 AC Overshoot / Undershoot Specification for Clock, Data, Strobe and Mask pins:
Applies to DQ, LDQS,
LDQS
, UDQS,
UDQS
, LDM, UDM, CLK,
CLK
PARAMETER
DDR2-1066
DDR2-800
DDR2-667
UNIT
Maximum peak amplitude allowed for overshoot area
0.5
0.5
0.5
V
Maximum peak amplitude allowed for undershoot area
0.5
0.5
0.5
V
Maximum overshoot area above VDDQ
0.19
0.23
0.23
V-nS
Maximum undershoot area below VSSQ
0.19
0.23
0.23
V-nS
Maximum Amplitude
Maximum Amplitude Overshoot Area
Undershoot Area
VDD/VDDQ
Volts (V)
Time (nS)
VSS/VSSQ
Figure 29 – AC overshoot and undershoot definition
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11. TIMING WAVEFORMS
11.1 Command Input Timing
CLK
CLK
tCK tCK tCLtCH
tIS tIH
tIS tIH
tIS tIH
tIS tIH
tIS tIH
CS
RAS
CAS
WE
A0~A12
BA0,1
Refer to the Command Truth Table
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11.2 ODT Timing for Active/Standby Mode
T1 T2 T3 T4 T5 T6 T7
CLK
CKE
Internal
Term Res.
T8
ODT
tAOFD
tAOND
tIS
RTT
CLK
tIS
tIS
VIL(ac)
VIH(ac)
T0
tAON(max)
tAOF(min) tAOF(max)
tAON(min)
11.3 ODT Timing for Power Down Mode
T1 T2 T3 T4 T5 T6 T7
CLK
CKE
Internal
Term Res.
T8
ODT
tIS
RTT
CLK
tIS
VIL(ac)
VIH(ac)
T0
tAONPD(max)
tAOFPD(min)
tAOFPD(max)
tAONPD(min)
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11.4 ODT Timing mode switch at entering power down mode
CLK T-5 T0
CKE
RTT
tAONPD(max)
tAOND
tAOFPD(max)
tAOFD
tANPD
tIS
CLK
Entering Slow Exit Active Power Down
Mode or Precharge Power Down Mode
tIS
tIS
tIS
tIS
T-4 T-3 T-2 T-1 T1 T2
VIL(ac)
VIL(ac)
VIH(ac)
VIH(ac)
ODT
ODT
ODT
ODT
Internal
Term Res.
Internal
Term Res.
Internal
Term Res.
Internal
Term Res.
Active & Standby
mode timings to be
applied
Active & Standby
mode timings to be
applied
Power Down mode
timings to be applied
Power Down mode
timings to be applied
RTT
RTT
RTT
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11.5 ODT Timing mode switch at exiting power down mode
CLK T0 T7 T8 T9 T10
CKE
RTT
RTT
RTT
RTT
RTT
ODT
Active & Standby mode
timings to be applied
Power Down mode
timings to be applied
tIS
CLK
Internal
Term Res.
tAXPD
Exiting from Slow Active Power Down Mode
or Precharge Power Down Mode
T1 T5 T6
tIS
tIS
tIS
tIS
tAOFD
tAOFPD(max)
tAONPD(max)
tAOND
VIL(ac)
VIL(ac)
VIH(ac)
VIH(ac)
Internal
Term Res.
Internal
Term Res.
Internal
Term Res.
ODT
ODT
ODT
Active & Standby mode
timings to be applied
Power Down mode
timings to be applied
VIH(ac)
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11.6 Data output (read) timing
CLK
DQS
DQ
tDQSQmax tDQSQmax
Q
tQH
tRPST
tCLtCH
Q Q Q
CLK
DQS
tQH
tRPRE
DQS
DQS
11.7 Burst read operation: RL=5 (AL=2, CL=3, BL=4)
NOP
NOPNOP
T0 T1 T2 T3 T4 T5 T6 T7
CLK/CLK
CMD
DQS,
DQS
DQ's
T8
NOP NOP NOP NOP
Dout
A0
RL = 5
CL = 3
≤ tDQSCK
NOP
Dout
A3
Dout
A1 Dout
A2
AL = 2
Posted CAS
READ A NOP NOP NOP NOP NOP NOP NOP NOP
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11.8 Data input (write) timing
VIH(ac)
VIL(ac)
D D D D
VIH(dc)
VIL(dc)
VIH(dc)
VIL(dc)
DMin
DMin
DMin
tDS
VIH(ac)
VIL(ac)
tWPRE
tDQSH tDQSL
DQS
DQS
tWPST
tDS tDH tDH
DMin
DQS
DQ
DM
DQS
11.9 Burst write operation: RL=5 (AL=2, CL=3, WL=4, BL=4)
T0 T1 T2 T3 T4 T5 T6 T7 Tn
DIN
A0 DIN
A1 DIN
A2 DIN
A3
DIN
A0 DIN
A1 DIN
A2 DIN
A3
tDQSS tDQSS
tDSS
tDSS Completion of
The Burst Write
NOP NOPNOPNOPNOPNOPNOP
Posted CAS
WRITE A
tDQSS
tDSH
tDQSS
≥ tWR
Precharge
CLK
CMD
DQS
DQs
DQs
Case 1: with tDQSS(max)
Case 2: with tDQSS(min)
WL = RL – 1= 4
WL = RL – 1= 4
tDSH
DQS
CLK
DQS
DQS
≥ tWR
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11.10 Seamless burst read operation: RL = 5 ( AL = 2, and CL = 3, BL = 4)
T0 T1 T2 T5T3 T6T4 T7 T8
Post CAS
READ A Post CAS
READ B
NOP NOP NOP NOP NOP NOP NOP
DOUT
A0 DOUT
A1 DOUT
A2 DOUT
A3 DOUT
B0 DOUT
B1 DOUT
B2
CLK
CLK
CMD
DQS
DQS
DQ's
AL = 2 CL = 3
RL = 5
Note:
The seamless burst read operation is supported by enabling a read command at every other clock for BL = 4 operation, and
every 4 clock for BL = 8 operation. This operation is allowed regardless of same or different banks as long as the banks are
activated.
11.11 Seamless burst write operation: RL = 5 ( WL = 4, BL = 4)
T0 T1 T2 T5
T3 T6
T4 T7 T8
Post CAS
Write A Post CAS
Write B
NOP NOP NOP NOP NOP NOP NOP
DIN
A0 DIN
A1 DIN
A2 DIN
A3 DIN
B0 DIN
B1 DIN
B2
CLK
CLK
CMD
DQS
DQS
DQ's DIN
B3
WL = RL - 1 = 4
Note:
The seamless burst write operation is supported by enabling a write command every other clock for BL = 4 operation, every four
clocks for BL = 8 operation. This operation is allowed regardless of same or different banks as long as the banks are activated.
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11.12 Burst read interrupt timing: RL =3 (CL=3, AL=0, BL=8)
NOPNOPNOPNOP
READ A
T0 T1 T2 T3 T4 T5 T6 T7
CLK/CLK
CMD
DQS,
DQS
T8
NOP
Dout
A0 Dout
A1 Dout
A2 Dout
A3 Dout
B0 Dout
B1 Dout
B2 Dout
B3 Dout
B4 Dout
B5 Dout
B6 Dout
B7
READ B NOP
NOP
DQ's
11.13 Burst write interrupt timing: RL=3 (CL=3, AL=0, WL=2, BL=8)
Write A NOPNOPWrite BNOP
T0 T1 T2 T3 T4 T5 T6 T7
CLK/CLK
CMD
DQS,
DQS
T8
NOPNOP NOPNOP
Din
A0 Din
A1 Din
A2 Din
A3 Din
B0 Din
B1 Din
B2 Din
B3 Din
B4 Din
B5 Din
B6 Din
B7
DQ's
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11.14 Write operation with Data Mask: WL=3, AL=0, BL=4)
DQS/
DQS
DQ
DM VIH(ac) VIH(dc)
tDS tDH tDS tDH
WL + tDQSS (max)
tWR
WL + tDQSS (min)
Write
CLK
CMDMAND
DQS/DQS
DQ
DM
DQ
DM
Case 1: min tDQSS
Case 2: max tDQSS
CLK
DQS/DQS
VIL(dc)
VIL(ac)
VIH(ac)
VIL(ac)
VIH(dc)
VIL(dc)
Data Mask Timing
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11.15 Burst read operation followed by precharge: RL=4 (AL=1, CL=3, BL=4, tRTP
≤ 2clks)
Precharge NOP Bank A
Activate
NOPNOPNOP
Post CAS
READ A NOP
T0 T1 T2 T3 T4 T5 T6 T7
CLK/CLK
CMD
DQS,
DQS
T8
≥ tRAS
≥ tRTP
AL+BL/2 clks ≥ tRP
AL = 1 CL = 3
RL = 4
NOP
Dout
A0 Dout
A1 Dout
A2 Dout
A3
DQ's
11.16 Burst read operation followed by precharge: RL=4 (AL=1, CL=3, BL=8, tRTP
≤ 2clks)
NOP Precharge NOP NOPNOPNOPNOPNOP
Post CAS
READ A
T0 T1 T2 T3 T4 T5 T6 T7 T8
≥ tRTP
AL + BL/2 clks
AL = 1 CL = 3
RL = 4 Dout
A0 Dout
A1 Dout
A2 Dout
A3 Dout
A4 Dout
A5 Dout
A6 Dout
A7
first 4-bit prefetch second 4-bit prefetch
CLK/CLK
CMD
DQS,
DQS
DQ's
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11.17 Burst read operation followed by precharge: RL=5 (AL=2, CL=3, BL=4, tRTP
≤ 2clks)
NOP
NOP
Precharge
NOP
NOPNOP
Post CAS
READ A Bank A
Activate
T0 T1 T2 T3 T4 T5 T6 T7 T8
≥ tRAS
≥ tRTP
AL + BL/2 clks ≥ tRP
AL = 2 CL = 3
RL = 5 Dout
A0 Dout
A1 Dout
A2 Dout
A3
NOP
CL = 3
CLK/CLK
CMD
DQS,
DQS
DQ's
11.18 Burst read operation followed by precharge: RL=6 (AL=2, CL=4, BL=4, tRTP
≤ 2clks)
Dout
A0 Dout
A1 Dout
A2 Dout
A3
NOP
NOPNOP
Precharge
NOPNOPNOP
Post CAS
READA Bank A
Activate
T0 T1 T2 T3 T4 T5 T6 T7
CLK/CLK
CMD
DQS,
DQS
DQ's
T8
≥ tRAS
≥ tRTP
AL + BL/2 clks ≥ tRP
AL = 2 CL = 4
RL = 6
CL = 4
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 79 -
11.19 Burst read operation followed by precharge: RL=4 (AL=0, CL=4, BL=8, tRTP
> 2clks)
Dout
A0 Dout
A1 Dout
A2 Dout
A3
NOP
NOPPrecharge
NOP
NOP
NOPNOP
Post CAS
READ A Bank A
Activate
T0 T1 T2 T3 T4 T5 T6 T7
CLK/CLK
CMD
DQS,
DQS
DQ's
T8
Dout
A5 Dout
A6 Dout
A7
Dout
A4
CL = 4
RL = 4
≥ tRAS
≥ tRTP
AL + BL/2 + max(RTP, 2) - 2 clks
≥ tRP
first 4-bit prefetch second 4-bit prefetch
AL = 0
11.20 Burst write operation followed by precharge: WL = (RL-1) = 3
NOPNOPNOPNOPNOPNOPNOP
Post CAS
WRITE A Precharge
T0 T1 T2 T3 T4 T5 T6 T7
CLK/CLK
CMD
DQS,
DQS
DQ's
T8
WL = 3
Completion of the Burst Write
DIN
A0 DIN
A1 DIN
A2 DIN
A3
≥ tWR
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 80 -
11.21 Burst write operation followed by precharge: WL = (RL-1) = 4
NOPNOPNOPNOP
NOP
NOPNOP
Posted CAS
WRITE A Precharge A
T0 T1 T2 T3 T4 T5 T6 T7
CLK/CLK
CMD
DQS,
DQS
DQ's
T9
WL = 4
Completion of the Burst Write
≥ tWR
DIN A0 DIN A1 DIN A2 DIN A3
11.22 Burst read operation with Auto-precharge: RL=4 (AL=1, CL=3, BL=8, tRTP ≤
2clks)
NOP NOP NOP Bank A
Activate
NOPNOPNOPNOP
Post CAS
READA
T0 T1 T2 T3 T4 T5 T6 T7
CLK/CLK
CMD
DQS,
DQS
DQ's
T8
≥ tRTP
AL + BL/2 clks ≥ tRP
AL = 1 CL = 3
RL = 4 Dout
A0 Dout
A1 Dout
A2 Dout
A3 Dout
A4 Dout
A5 Dout
A6 Dout
A7
first 4-bit prefetch second 4-bit prefetch tRTP Precharge begins here
A10 = 1
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 81 -
11.23 Burst read operation with Auto-precharge: RL=4 (AL=1, CL=3, BL=4, tRTP >
2clks)
NOP NOP Bank A
Activate
NOPNOPNOP
Post CAS
READA NOP
T0 T1 T2 T3 T4 T5 T6 T7
CLK/CLK
CMD
DQS,
DQS
T8
tRTP
≥ AL + tRTP + tRP
AL = 1 CL = 3
RL = 4
NOP
Dout
A0 Dout
A1 Dout
A2 Dout
A3
DQ's
4-bit prefetch
Precharge begins here tRP
A10 = 1
11.24 Burst read with Auto-precharge followed by an activation to the same bank
(tRC Limit): RL=5 (AL=2, CL=3, internal tRCD=3, BL=4, tRTP ≤ 2clks)
NOP NOP NOP
NOPNOPNOP
Post CAS
READA Bank A
Activate
T0 T1 T2 T3 T4 T5 T6 T7
CLK/CLK
CMD
DQS,
DQS
T8
≥ tRAS min. (AL + BL/2)
AL = 2 CL = 3
RL = 5
NOP
Dout
A0 Dout
A1 Dout
A2 Dout
A3
DQ's
Auto-precharge begins
A10 = 1
≥ tRP
tRC min.
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 82 -
11.25 Burst read with Auto-precharge followed by an activation to the same bank
(tRP Limit): RL=5 (AL=2, CL=3, internal tRCD=3, BL=4, tRTP ≤ 2clks)
NOP NOP NOP
NOPNOPNOP
Post CAS
READA Bank A
Activate
T0 T1 T2 T3 T4 T5 T6 T7
CLK/CLK
CMD
DQS,
DQS
T8
≥ tRAS min.
AL = 2 CL = 3
RL = 5
NOP
Dout
A0 Dout
A1 Dout
A2 Dout
A3
DQ's
Auto-precharge begins
A10 = 1
tRP min.
≥ tRC
11.26 Burst write with Auto-precharge (tRC Limit): WL=2, WR=2, BL=4, tRP=3
tRC min.
WL= RL- 1 = 2
≥ WR ≥ tRP
NOPNOPNOPNOPNOPNOPNOP
Post CAS
WRA Bank A Bank A
Activate
T0 T1 T2 T3 T4 T5 T6 T7
Auto-precharge Begins
A10 = 1
CLK/CLK
CMD
DQS,
DQS
DQ's
Completion of the Burst Write
Tm
DIN
A0 DIN
A1 DIN
A2 DIN
A3
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 83 -
11.27 Burst write with Auto-precharge (WR + tRP Limit): WL=4, WR=2, BL=4, tRP=3
≥ tRC
WL = RL - 1 = 4 ≥ WR tRP min.
NOP
NOPNOP
NOPNOP
NOP
NOP
Post CAS
WRA Bank A Bank A
Activate
T0 T3 T4 T5 T6 T7 T8 T9
Completion of the Burst Write Auto-precharge Begins
A10 = 1
CLK/CLK
CMD
DQS,
DQS
T11
DQ's DIN
A0 DIN
A1 DIN
A2 DIN
A3
11.28 Self Refresh Timing
T0 T1 T2 T3 T4 T5 T6 Tm Tn
Self
Refresh NOP Non-Read
Command NOP
≥ tXSNR
≥ tXSRD
tIH
tIH
tIS
tIH
tIHtIS
tIS
tRP
tIS
tAOFD
tCK
tCH tCL
VIL(ac)
VIH(ac)
VIL(ac)
VIH(ac) VIL(dc)
VIH(dc)
CLK
CMD
CKE
ODT
CLK
VIL(ac)
Read
Command
Notes:
1. Device must be in the “All banks idle” state prior to entering Self Refresh mode.
2. ODT must be turned off tAOFD before entering Self Refresh mode, and can be turned on again when tXSRD timing is
satisfied.
3. tXSRD is applied for a Read or a Read with Auto-precharge command. tXSNR is applied for any command except a Read or a
Read with Auto-precharge command.
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 84 -
11.29 Basic Power Down Entry and Exit Timing
CLK
CLK
VALID NOP
tIS
NOP NOP VALID VALID
or NOP
tIH tIH tIS
tCKEmin
tXARDS
Power-Down Mode Entry Power-Down Mode Exit
tXP, tXARD
CMD
CKE
Don't Care
tIH tIS tIH
tCKEmin
11.30 Precharged Power Down Entry and Exit Timing
CLK
CLK
Precharge NOP
tIS
VALID
tIH tIH tIS
tCKEmin
Precharge Power-Down Entry Precharge Power-Down Exit
CMD
CKE
Don't Care
1 x tCK
NOP NOP
tXP
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 85 -
11.31 Clock frequency change in precharge Power Down mode
NOP NOP NOP NOP NOP Valid
T0 T1 T2 T4 TXTX+1 TYTY+1 TY+2 TY+3 TY+4 Tz
CLK
tIS
DLL
RESET
Minimum 2 clocks
required before
changing frequency Stable new clock
before power down exit
Frequency change
Occurs here
200 Clocks
ODT is off during
DLL RESET
CLK
CMD
CKE
ODT
tIS
tIH
tRP
tAOFD tXP
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 86 -
12. PACKAGE SPECIFICATION
Package Outline WBGA-84 (8x12.5 mm2, ball pitch: 0.8mm, Ø =0.45mm)
1
84xΦb
A1 A
SEATING PLANE
SYMBOL DIMENSION (MM)
MIN. NOM. MAX.
A
A1
b
D
E
D1
E1
eE
eD
aaa
bbb
ccc --- ---
--- --- 0.10
0.20
--- --- 0.15
0.80 BSC.
0.80 BSC.
6.40 BSC.
11.20 BSC.
1.20
0.40
0.50
12.60
8.10
8.00
12.50
7.90
12.40
0.40
0.25
D
eE
E1
eD
D1
237
89
E
---
---
------
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
C
ccc
C
A
C
aaa
B
C
bbb
//
PIN A1 INDEX PIN A1 INDEX
BALL LAND
BALL OPENING
Note:
1. Ball land: 0.5mm, Ball opening: 0.4mm, PCB Ball land
suggested ≤ 0.4mm
SOLDER BALL DIAMETER REFERS.
TO POST REFLOW CONDITION.
THE WINDOW-SIDE
ENCAPSULANT
eee C A
CB
M
ddd M
ddd
eee --- ---
--- --- 0.08
0.15
1
W9725G6KB
Publication Release Date: Feb. 07, 2017
Revision: A04
- 87 -
13. REVISION HISTORY
VERSION
DATE
PAGE
DESCRIPTION
A01
Apr. 25, 2012
All
Initial formal datasheet
A02
Jul. 06, 2012
4, 5, 13, 37, 38,
40~42, 45, 46
Added 25A and 25K automotive grade parts
A03
Sep. 03, 2012
9
Added VTT voltage ramp time required condition in
section 8.1 power-up and initialization sequence
83
Added notes for 11.28 self refresh timing diagram
86
Added “ddd” and “eee” symbols in WBGA84
package outline drawing diagram
A04
Dec. 02, 2015
4, 5, 13, 37, 38,
40~42, 45, 46
Removed 25A and 25K automotive grade parts
Feb. 07, 2017
39
40
52
87
Removed VOH and VOL parameters in section 10.8
table
Typo correction for "Data bus"
" Subscript correction for "tCKi +1"
Remove ”important notice”
