Etron EM68C08CWAE-25IH 128m x 8 bit ddrii synchronous dram (sdram) Datasheet

EtronTech
EM68C08CWAE
128M x 8 bit DDRII Synchronous DRAM (SDRAM)
Advanced (Rev. 1.1, Jul. /2014)
Features
Overview
• JEDEC Standard Compliant
• JEDEC standard 1.8V I/O (SSTL_18-compatible)
• Power supplies: VDD & VDDQ = +1.8V ± 0.1V
• Industrial temperature: TC = -40~95°C
• Supports JEDEC clock jitter specification
• Fully synchronous operation
• Fast clock rate: 333/400/533 MHz
• Differential Clock, CK & CK#
• Bidirectional single/differential data strobe
• 8 internal banks for concurrent operation
• 4-bit prefetch architecture
• Internal pipeline architecture
• Precharge & active power down
• Programmable Mode & Extended Mode registers
• Posted CAS# additive latency (AL): 0, 1, 2, 3, 4, 5, 6
• WRITE latency = READ latency - 1 tCK
• Burst lengths: 4 or 8
• Burst type: Sequential / Interleave
• DLL enable/disable
• On-die termination (ODT)
• RoHS compliant
• Auto Refresh and Self Refresh
• 8192 refresh cycles / 64ms
- Average refresh period
7.8µs @ -40°C ≦TC≦ +85°C
3.9µs @ +85°C ＜TC≦ +95°C
• 60-ball 8 x 10 x 1.2mm (max) FBGA package
- Pb and Halogen Free
The EM68C08C is a high-speed CMOS DoubleData-Rate-Two (DDR2), synchronous dynamic random
- access memory (SDRAM) containing 1024 Mbits in a
8-bit wide data I/Os. It is internally configured as a 8bank DRAM, 8 banks x 16Mb addresses x 8 I/Os.
The device is designed to comply with DDR2 DRAM
key features such as posted CAS# with additive latency,
Write latency = Read latency -1 and On Die
Termination(ODT).
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 (CK rising and CK# falling)
All I/Os are synchronized with a pair of bidirectional
strobes (DQS and DQS#) in a source synchronous
fashion. The address bus is used to convey row,
column, and bank address information in RAS #, CAS#
multiplexing style. Accesses begin with the registration
of a Bank Activate command, and then it is followed by
a Read or Write command. Read and write accesses to
the DDR2 SDRAM are 4 or 8-bit burst oriented;
accesses start at a selected location and continue for a
programmed number of locations in a programmed
sequence.
Operating the eight memory banks in an interleaved
fashion allows random access operation to occur at a
higher rate than is possible with standard DRAMs. An
auto precharge function may be enabled to provide a
self-timed row precharge that is initiated at the end of
the burst sequence. A sequential and gapless data rate
is possible depending on burst length, CAS latency,
and speed grade of the device.
Table 1. Ordering Information
Part Number
Clock Frequency
Data Rate
EM68C08CWAE-18IH
533MHz
1066Mbps/pin
EM68C08CWAE-25IH
400MHz
800Mbps/pin
EM68C08CWAE-3IH
333MHz
667Mbps/pin
WA: indicates 8 x 10 x 1.2mm FBGA Package
E: indicates Generation Code
I: indicates Industrial Grade
H: indicates Pb and Halogen Free for FBGA Package
Power Supply
VDD 1.8V, VDDQ 1.8V
VDD 1.8V, VDDQ 1.8V
VDD 1.8V, VDDQ 1.8V
Package
FBGA
FBGA
FBGA
Etron Technology, Inc.
No. 6, Technology Rd. V, Hsinchu Science Park, Hsinchu, Taiwan 30078, R.O.C.
TEL: (886)-3-5782345
FAX: (886)-3-5778671
Etron Technology, Inc. reserves the right to change products or specification without notice.
EtronTech
EM68C08CWAE
Table 2. Speed Grade Information
Speed Grade
Clock Frequency
CAS Latency
tRCD (ns)
tRP (ns)
DDR2-1066
533 MHz
7
13.125
13.125
DDR2-800
400 MHz
5
12.5
12.5
DDR2-667
333 MHz
5
15
15
Figure 1. Ball Assignment (FBGA Top View)
1
2
3
7
8
9
A
VDD
RDQS#
VSS
VSSQ
DQS#
VDDQ
B
DQ6
VSSQ
DM/
RDQS
DQS
VSSQ
DQ7
C
VDDQ
DQ1
VDDQ
VDDQ
DQ0
VDDQ
D
DQ4
VSSQ
DQ3
DQ2
VSSQ
DQ5
E
VDDL
VREF
VSS
VSSDL
CK
VDD
CKE
WE#
RAS#
CK#
ODT
BA0
BA1
CAS#
CS#
A10
A1
A2
A0
A3
A5
A6
A4
A7
A9
A11
A8
A12
NC
NC
A13
F
G
BA2
H
J
VSS
K
L
Rev. 1.1
VDD
2
VDD
VSS
Jul. /2014
EtronTech
EM68C08CWAE
Figure 2. Block Diagram
DLL
CLOCK
BUFFER
Row
Decoder
CK
CK#
Column Decoder
CONTROL
SIGNAL
GENERATOR
16M x 8
CELL ARRAY
(BANK #1)
Column Decoder
Row
Decoder
COMMAND
DECODER
Row
Decoder
CKE
CS#
RAS#
CAS#
WE#
16M x 8
CELL ARRAY
(BANK #0)
16M x 8
CELL ARRAY
(BANK #2)
A10/AP
COLUMN
COUNTER
MODE
REGISTER
Row
Decoder
Column Decoder
16M x 8
CELL ARRAY
(BANK #3)
Column Decoder
ADDRESS
BUFFER
Row
Decoder
A0~A9
A11~A13
BA0~BA2
16M x 8
CELL ARRAY
(BANK #4)
Row
Decoder
Column Decoder
REFRESH
COUNTER
16M x 8
CELL ARRAY
(BANK #5)
DQS
DQS#
RDQS
RDQS#
Row
Decoder
Column Decoder
DATA
STROBE
BUFFER
DQ
Buffer
16M x 8
CELL ARRAY
(BANK #6)
Column Decoder
DQ0
Row
Decoder
~
DQ7
16M x 8
CELL ARRAY
(BANK #7)
Column Decoder
ODT DM
Rev. 1.1
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EM68C08CWAE
Figure 3. State Diagram
CKEL
OCD
calibration
Initialization
Sequence
SRF H
CKE
PR
Setting
MR,
EMR(1)
EMR(2)
EMR(3)
(E)MRS
Idle
All banks
precharged
ACT
Self
Refreshing
REF
CK
EL
CK
EH
Refreshing
EL
CK
Precharge
Power
Down
Automatic Sequence
Cammand Sequence
Activating
Active
Power
Down
CKEH
CKE
L
WR
Bank
Active
RD
RD
Reading
W
WR
CKEL
L
CKE
RA
CKEL
Writing
WR
RD
A
RD
CKEL = CKE LOW, enter Power Down
RDA
A
WR
WRA
Writing
With
Autoprecharge
PR, PRA
PR, PRA
CKEH = CKE HIGH, exit Power Down,exit Self Refresh
ACT = Activate
RDA
Reading
With
Autoprecharge
PR, PRA
WR(A) = Write (with Autoprecharge)
RD(A) = Read (with Autoprecharge)
PR(A) = Precharge (All)
(E)MRS = (Extended) Mode Register Set
SRF = Enter Self Refresh
Precharging
REF = Refresh
Note: Use caution with this diagram. It is indented to provide a floorplan of the possible state transitions and the
commands to control them, not all details. In particular situations involving more than one bank,
enabling/disabling on-die termination, Power Down entry/exit, timing restrictions during state transitions, among
other things, are not captured in full detail.
Rev. 1.1
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EM68C08CWAE
Ball Descriptions
Table 3. Ball Descriptions
Symbol
Type
Description
CK, CK#
Input
Differential Clock: CK, CK# are driven by the system clock. All SDRAM input signals are
sampled on the crossing of positive edge of CK and negative edge of CK#. Output (Read)
data is referenced to the crossings of CK and CK# (both directions of crossing).
CKE
Input
Clock Enable: CKE activates (HIGH) and deactivates (LOW) the CK signal. If CKE goes
LOW synchronously with clock, the internal clock is suspended from the next clock cycle
and the state of output and burst address is frozen as long as the CKE remains LOW.
When all banks are in the idle state, deactivating the clock controls the entry to the Power
Down and Self Refresh modes.
BA0-BA2
Input
Bank Address: BA0-BA2 define to which bank the BankActivate, Read, Write, or
BankPrecharge command is being applied.
A0-A13
Input
Address Inputs: A0-A13 are sampled during the BankActivate command (row address
A0-A13) and Read/Write command (column address A0-A9 with A10 defining Auto
Precharge). A13 Row Address use on x8 components only.
CS#
Input
Chip Select: CS# enables (sampled LOW) and disables (sampled HIGH) the command
decoder. All commands are masked when CS# is sampled HIGH. CS# provides for
external bank selection on systems with multiple banks. It is considered part of the
command code.
RAS#
Input
Row Address Strobe: The RAS# signal defines the operation commands in conjunction
with the CAS# and WE# signals and is latched at the crossing of positive edges of CK
and negative edge of CK#. When RAS# and CS# are asserted "LOW" and CAS# is
asserted "HIGH," either the BankActivate command or the Precharge command is
selected by the WE# signal. When the WE# is asserted "HIGH," the BankActivate
command is selected and the bank designated by BA is turned on to the active state.
When the WE# is asserted "LOW," the Precharge command is selected and the bank
designated by BA is switched to the idle state after the precharge operation.
CAS#
Input
Column Address Strobe: The CAS# signal defines the operation commands in
conjunction with the RAS# and WE# signals and is latched at the crossing of positive
edges of CK and negative edge of CK#. When RAS# is held "HIGH" and CS# is asserted
"LOW," the column access is started by asserting CAS# "LOW." Then, the Read or Write
command is selected by asserting WE# “HIGH " or “LOW".
WE#
Input
Write Enable: The WE# signal defines the operation commands in conjunction with the
RAS# and CAS# signals and is latched at the crossing of positive edges of CK and
negative edge of CK#. The WE# input is used to select the BankActivate or Precharge
command and Read or Write command.
DQS,
Input /
DQS#
Output
Bidirectional Data Strobe: output with read data, input with write data. Edge aligned with
read data, centered with write data. For the RDQS option using DM pin can be enabled
via the EMR(1) to simplify read timing.The data strobes DQS and RDQS may be used in
single ended mode or paired with the optional complementary signals DQS# and RDQS#
to provide differential pair signaling to the system during both reads and writes. An EMRS
(1) control bit enables or disables the complementary data strobe signals.
RDQS
RDQS#
DM
Input
DQ0 – DQ7
Input /
Output
ODT
Input
Rev. 1.1
Data Input Mask: Input data is masked when DM is sampled HIGH during a write cycle.
x8 device, the function of DM or RDQS/RQDS# is enabled by EMRS command.
Data I/O: Bi-directional data bus.
On Die Termination: ODT enables internal termination resistance. It is applied to each
DQ, DQS/DQS#, RDQS/RDQS# and DM signal. The ODT pin is ignored if the EMR (1) is
programmed to disable ODT.
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EM68C08CWAE
VDD
Supply
Power Supply: +1.8V ±0.1V
VSS
Supply
Ground
VDDL
Supply
DLL Power Supply: +1.8V ±0.1V
VSSDL
Supply
DLL Ground
VDDQ
Supply
DQ Power: +1.8V ±0.1V.
VSSQ
Supply
DQ Ground
VREF
Supply
Reference Voltage for Inputs: +0.5*VDDQ
NC
-
Rev. 1.1
No Connect: These pins should be left unconnected.
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EM68C08CWAE
Operation Mode
Table 4 shows the truth table for the operation commands.
Table 4. Truth Table (Note (1), (2))
Command
BankActivate
State CKEn-1 CKEn DM BA0-2 A10 A0-9, 11-13 CS# RAS# CAS# WE#
Idle(3)
H
H
X
V
Row address
L
L
H
H
Single Bank Precharge
Any
H
H
X
V
L
X
L
L
H
L
All Banks Precharge
Any
H
H
X
X
H
X
L
L
H
L
Column
address
L
H
L
L
L
H
L
L
L
H
L
H
L
H
L
H
L
L
L
L
Write
Active(3)
H
H
X
V
L
Write with AutoPrecharge
Active(3)
H
H
X
V
H
Read
Active(3)
H
H
X
V
L
Read and Autoprecharge
Active(3)
H
H
X
V
H
(Extended) Mode Register Set
Idle
H
H
X
V
No-Operation
Any
H
X
X
X
X
X
L
H
H
H
Active(4)
H
X
X
X
X
X
L
H
H
L
Device Deselect
Any
H
X
X
X
X
X
H
X
X
X
Refresh
Idle
H
H
X
X
X
X
L
L
L
H
SelfRefresh Entry
Idle
H
L
X
X
X
X
L
L
L
H
SelfRefresh Exit
Idle
L
H
X
X
X
X
H
X
X
X
L
H
H
H
Power Down Mode Entry
Idle
H
L
X
X
X
X
H
X
X
X
L
H
H
H
Power Down Mode Exit
Any
L
H
X
X
X
X
H
X
X
X
L
H
H
H
Data Input Mask Disable
Active
H
X
L
X
X
X
X
X
X
X
Data Input Mask Enable(5)
Active
H
X
H
X
X
X
X
NOTE 1: V=Valid data, X=Don't Care, L=Low level, H=High level
NOTE 2: CKEn signal is input level when commands are provided.
NOTE 3: CKEn-1 signal is input level one clock cycle before the commands are provided.
NOTE 4: These are states of bank designated by BA signal.
NOTE 5: Device state is 4, and 8 burst operation.
NOTE 6: LDM and UDM can be enabled respectively.
X
X
X
Burst Stop
Rev. 1.1
7
(A0 – A9)
Column
address
(A0 – A9)
OP code
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EM68C08CWAE
Functional Description
Read and write accesses to the DDR2 SDRAM are burst oriented; accesses start at a selected location and
continue for a burst length of four or eight in a programmed sequence. Accesses begin with the registration of an
Active command, which is then followed by a Read or Write command. The address bits registered coincident with
the active command are used to select the bank and row to be accessed (BA0-BA2 select the bank; A0-A13 select
the row). The address bits registered coincident with the Read or Write command are used to select the starting
column location for the burst access and to determine if the auto precharge command is to be issued.
Prior to normal operation, the DDR2 SDRAM must be initialized. The following sections provide detailed information
covering device initialization, register definition, command descriptions, and device operation.
z Power-up and Initialization
DDR2 SDRAMs must be powered up and initialized in a predefined manner. Operational procedures other than
those specified may result in undefined operation.
The following sequence is required for POWER UP and Initialization.
1. Apply power and attempt to maintain CKE below 0.2*VDDQ and ODT *1 at a low state (all other inputs may be
undefined.) The VDD voltage ramp time must be no greater than 200ms from when VDD ramps from 300mV to
VDDmin; and during the VDD voltage ramp, |VDD-VDDQ| ≦ 0.3V
- VDD, VDDL and VDDQ are driven from a single power converter output, AND
- VTT is limited to 0.95 V max, AND
- VREF tracks VDDQ/2.
or
- Apply VDD before or at the same time as VDDL.
- Apply VDDL before or at the same time as VDDQ.
- Apply VDDQ before or at the same time as VTT & VREF.
At least one of these two sets of conditions must be met.
2. Start clock and maintain stable condition.
3. For the minimum of 200µs after stable power and clock (CK, CK#), then apply NOP or deselect and take CKE
HIGH.
4. Wait minimum of 400ns then issue precharge all command. NOP or deselect applied during 400ns period.
5. Issue EMRS(2) command. (To issue EMRS (2) command, provide “LOW” to BA0 and BA2, “HIGH” to BA1.)
6. Issue EMRS (3) command. (To issue EMRS (3) command, provide “LOW” to BA2, “HIGH” to BA0 and BA1.)
7. Issue EMRS to enable DLL. (To issue "DLL Enable" command, provide "LOW" to A0, "HIGH" to BA0 and
"LOW" to BA1 and BA2.)
8. Issue a Mode Register Set command for “DLL reset”.
(To issue DLL reset command, provide "HIGH" to A8 and "LOW" to BA0-BA2)
9. Issue precharge all command.
10. Issue 2 or more auto-refresh commands.
11. Issue a mode register set 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 OCD Default command (A9=A8=A7=HIGH) followed by EMRS OCD calibration
Mode Exit command (A9=A8=A7=LOW) must be issued with other operating parameters of EMRS.
13. The DDR2 SDRAM is now ready for normal operation.
NOTE 1: To guarantee ODT off, VREF must be valid and a LOW level must be applied to the ODT pin.
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EM68C08CWAE
z Mode Register Set (MRS)
The mode register stores the data for controlling the various operating modes of DDR2 SDRAM. It controls CAS
latency, burst length, burst sequence, test mode, DLL reset, WR, and various vendor specific options to make
DDR2 SDRAM useful for various applications.The default value of the mode register is not defined, therefore the
mode register must be programmed during initialization for proper operation. The mode register is written by
asserting LOW on CS#, RAS#, CAS#, WE#, BA0 and BA1, while controlling the state of address pins A0 - A13.
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 bank are in the precharge state.The mode register is divided into various
fields depending on functionality.
- Burst Length Field (A2, A1, A0) : This field specifies the data length of column access and selects the Burst Length.
- Addressing Mode Select Field (A3) : The Addressing Mode can be Interleave Mode or Sequential Mode. Both Sequential
Mode and Interleave Mode support burst length of 4 and 8.
- CAS Latency Field (A6, A5, A4) : This field specifies the number of clock cycles from the assertion of the Read command to
the first read data. The minimum whole value of CAS Latency depends on the frequency of
CK. The minimum whole value satisfying the following formula must be programmed into
this field. (tCAC(min) ≦ CAS Latency X tCK)
- Test Mode Field (A7); DLL Reset Mode Field (A8) : These two bits must be programmed to "00" in normal operation.
- Write recovery Field (A11, A10, A9) : The WR register is used by the DDR2 SDRAM during WRITE with auto precharge
operation. The WR register is used by the DDR2 SDRAM during WRITE with auto
precharge operation.
- Active Power down Field (A12) : PD mode enables the user to determine the active power-down mode, which determines
performance versus power savings. oes not apply to precharge PD mode.
- (BA0-BA1): Bank addresses to define MRS selection.
Table 5. Mode Register Bitmap
BA2 BA1 BA0 A13 A12 A11 A10 A9
0*2
0*2
0
0
PD
A8
0
1
DLL Reset
No
Yes
WR
A12 Active power down exit time
0
Fast exit (use tXARD)
1
Slow exit (use tXARDS)
A8
A7
DLL TM
A7
0
1
Mode
Normal
Test
A6
A5
A4
A3
A2
A0
Address Field
CAS Latency
BT
Burst Length
Mode Register
A3
0
1
A1
Burst Type
Sequential
Interleave
A2
0
0
A1
1
1
A0
0
1
BL
4
8
*1
Write recovery for autoprecharge
A11 A10
A9
WR(cycles)
0
0
0
Reserved
0
0
1
2
A6
0
0
A5
0
0
A4
0
1
CAS Latency
Reserved
Reserved
BA1
BA0
MRS Mode
0
1
0
3
0
1
0
Reserved
0
0
1
1
0
1
0
1
MR
EMR(1)
EMR(2)
EMR(3)
0
1
1
1
1
1
0
0
1
1
1
0
1
0
1
4
5
6
7
8
0
1
1
1
1
1
0
0
1
1
1
0
1
0
1
3
4
5
6
7
NOTE 1: WR 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.
NOTE 2: BA2 and A13 are reserved for future use and must be set to 0 when programming the MR.
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z Extended Mode Register Set (EMRS)
- EMR(1)
The extended mode register(1) stores the data for enabling or disabling the DLL, output driver strength, ODT
value selection and additive latency. The default value of the extended mode register is not defined, therefore
the extended mode register must be written after power-up for proper operation. The extended mode register is
written by asserting LOW on CS#, RAS#, CAS#, WE#, BA1 and HIGH on BA0, while controlling the states of
address pins A0 ~ A13. The DDR2 SDRAM should be in all bank precharge with CKE already HIGH prior to
writing into the extended mode register. The mode register set command cycle time (tMRD) must be satisfied to
complete the write operation to the extended mode register. 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. A0 is used for DLL enable or disable. A1 is used for enabling a half strength data-output driver. A3~A5
determine the additive latency, A2 and A6 are used for ODT value selection, A7~A9 are used for OCD control,
A10 is used for DQS# disable and A11 is used for RDQS enable.
- 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 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.
Table 6. Extended Mode Register EMR (1) Bitmap
BA2 BA1 BA0 A13 A12 A11 A10 A9
0*3
0
1
RDQS DQS#
A7
A6
OCD program
A5
A4
A3
A2
BA0
0
1
0
MRS mode
MR
EMR(1)
EMR(2)
A6
0
0
1
A2
0
1
0
Rtt(NOMINAL)
ODT Disable
75Ω
1
1
EMR(3)
1
1
50Ω
A8
0
0
1
0
1
DQS#
Enable
Disable
A7
0
1
0
0
1
A1
OCD Calibration mode exit; maintain setting
Reserved
Reserved
Reserved
OCD Calibration default*1
0
1
*2
Qoff
Output buffer enabled
Output buffer disabled
A11
0
1
A0 Address Field
RDQS Enable
Disable
Enable
A0
0
1
150Ω
OCD Calibration Program
A12
0
1
A1
Rtt Additive Latency Rtt D.I.C DLL Extended Mode Register
BA1
0
0
1
A9
0
0
0
1
1
A10
0
1
0*3 Qoff
A8
*4
A5
0
0
0
0
1
1
1
1
A4
0
0
1
1
0
0
1
1
DLL Enable
Enable
Disable
Output Driver
Impedance Control
Full strength
Reduced strength
A3
0
1
0
1
0
1
0
1
Additive Latency
0
1
2
3
4
5
6
Reserved
NOTE 1: After setting to default, OCD calibration mode needs to be exited by setting A9-A7 to 000.
NOTE 2: Output disabled – DQs, DQSs, DQSs#, RDQS, RDQS#. This feature is intended to be used during IDD
characterization of read current.
NOTE 3: A13 and BA2 are reserved for future use and must be set to 0 when programming the MR.
NOTE 4: If RDQS is enabled, the DM function is disabled. RDQS is active for reads and do not care for writes.
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Table 7. Extended Mode Register EMR (1) Bitmap
A11
A10
(RDQS Enable)
0(Disable)
0(Disable)
1(Enable)
1(Enable)
(DQS# Enable)
0(Enable)
1(Disable)
0(Enable)
1(Disable)
RDQS
/DM
RDQS#
DQS
DQS#
DM
DM
RDQS
RDQS
Hi-z
Hi-z
RDQS#
Hi-z
DQS
DQS
DQS
DQS
DQS#
Hi-z
DQS#
Hi-z
- EMR(2)
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 written after power-up for proper
operation. The extended mode register(2) is written by asserting LOW on CS#, RAS#, CAS#, WE#, HIGH on
BA1 and LOW on BA0, while controlling the states of address pins A0 ~ A13. The DDR2 SDRAM should be in
all bank precharge 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.
Table 8. Extended Mode Register EMR(2) Bitmap
BA2 BA1 BA0 A13 A12 A11 A10 A9
0*3
1
0*1
0
A7
0
1
A8
A7
A6
A5
A4
SRF
A3
*1
0
A2
A1
A0 Address Field
Extended Mode Register(2)
High Temperature Self-Refresh Rate Enable
Disable
*2
Enable
NOTE 1: The rest bits in EMRS(2) are reserved for future use and all bits in EMRS(2) except A7, BA0 and BA1 must be
programmed to 0 when setting the extended mode register(2) during initialization.
NOTE 2: Due to the migration nature, user needs to ensure the DRAM part supports higher than 85℃ Tcase temperature
self-refresh entry. If the high temperature self-refresh mode is supported then controller can set the EMRS2[A7] bit
to enable the self-refresh rate in case of higher than 85℃ temperature self-refresh operation.
NOTE 3: BA2 is reserved for future use and must be set to 0 when programming the MR.
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- EMR(3)
No function is defined in extended mode register(3).The default value of the extended mode register(3) is not
defined, therefore the extended mode register(3) must be programmed during initialization for proper operation.
Table 9. Extended Mode Register EMR (3) Bitmap
BA2 BA1 BA0 A13 A12 A11 A10 A9
0*1
1
A8
A7
A6
0*1
1
A5
A4
A3
A2
A1
A0 Address Field
Extended Mode Register(3)
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).
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z ODT (On Die Termination)
On Die Termination (ODT) is a feature that allows a DRAM to turn on/off termination resistance for each DQ,
DQS/DQS#, RDQS/RDQS#, DM signal via the ODT control pin. 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 is supported for ACTIVE and STANDBY modes. It is turned off and not supported in SELF
REFRESH mode.
Figure 4. Functional representation of ODT
VDDQ
VDDQ
VDDQ
SW1
SW2
SW3
Rval1
Rval2
Rval3
DRAM
Input
Buffer
Input
pin
Rval1
Rval2
Rval3
SW1
SW2
SW3
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.
Termination included on all DQs, DM, DQS, DQS#, RDQS and RDQS# pins
Table 10. ODT DC Electrical Characteristics
Parameter/Condition
Symbol
Min.
Nom.
Max.
Unit Note
Rtt effective impedance value for EMRS(A6,A2)=0,1;75Ω Rtt1(eff)
60
75
90
Rtt effective impedance value for EMRS(A6,A2)=1,0;150Ω Rtt2(eff)
120
150
180
Rtt effective impedance value for EMRS(A6,A2)=1,1;50Ω Rtt3(eff)
40
50
60
Rtt mismatch tolerance between any pull-up/pull-down pair Rtt(mis)
-6
6
NOTE 1: Measurement Definition for Rtt(eff):
Apply VIH (ac) and VIL (ac) to test pin seperately, then measure current I(VIH(ac)) and I(VIL(ac))
respectively.
Rtt(eff)=
Ω
Ω
Ω
%
1
1
1
2
VIH (ac ) − VIL (ac )
I(VIH (ac))-I(VIL (ac))
NOTE 2: Measurement Defintion for Rtt (mis): Measure voltage (VM) at test pin (midpoint) with no load.
⎛ 2xVM ⎞
Rtt(mis)= ⎜
− 1⎟ ×100%
⎝ VDDQ
⎠
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z Bank activate command
The Bank Activate command is issued by holding CAS# and WE# HIGH with CS# and RAS# LOW at the rising
edge of the clock. The bank addresses BA0-BA2 are used to select the desired bank. The row addresses A0
through A13 are used to determine which row to activate in the selected bank. 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 (with or without Auto-Precharge) on the following clock cycle.
If a R/W command is issued to a bank that has not satisfied the tRCDmin specification, then additive latency must be
programmed into the device to delay the R/W command which 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, and 4 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 (tRC). The minimum time
interval between Bank Active commands is tRRD
In order to ensure that 8 bank devices do not exceed the instantaneous current supplying capability of 4 bank
devices, certain restrictions on operation of the 8 bank devices must be observed. There are two rules. One for
restricting the number of sequential ACT commands that can be issued and another for allowing more time for
RAS precharge for a Precharge All command. The rules are as follows:
- 8 bank device Sequential Bank Activation Restriction: No more than 4 banks may be activated in a rolling tFAW
window. Converting to clocks is done by dividing tFAW[ns] by tCK[ns] or tCK[ns], depending on the speed bin, and
rounding up to next integer value. As an example of the rolling window, if RU{ (tFAW / tCK) } or RU{ (tFAW / tCK)} is 10
clocks, and an activate command is issued in clock N, no more than three further activate commands may be
issued at or between clock N+1 and N+9.
- 8 bank device Precharge All Allowance : tRP for a Precharge All command for an 8 Bank device will equal to tRP +
1 x tCK or tRP + 1 x tCK, depending on the speed bin, where tRP = RU{ tRP / tCK} and tRP is the value for a single bank
precharge.
z Read and Write access modes
After a bank has been activated, a Read or Write cycle can be executed. This is accomplished by setting RAS#
HIGH, CS# and CAS# LOW at the clock’s rising edge. WE# must also be defined at this time to determine whether
the access cycle is a Read operation (WE# HIGH) or a Write operation (WE# LOW). 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. Any system or application incorporating random access memory products should be properly designed,
tested, and qualified to ensure proper use or access of such memory products. Disproportionate, excessive, and/or
repeated access to a particular address or addresses may result in reduction of product life.
z 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 R/W
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 (refer to seamless operation
timing diagram examples in Read burst and Write burst section)
z 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 the addresses A0 ~ A2 of the MRS. The burst type, either sequential or
interleaved, is programmable and defined by the address bit 3 (A3) of the MRS. Seamless burst Read or Write
operations are supported. Interruption of a burst Read or Write operation is prohibited, when burst length = 4 is
programmed. For burst interruption of a Read or Write burst when burst length = 8 is used, see the “Burst
Interruption“ section of this datasheet. A Burst Stop command is not supported on DDR2 SDRAM devices.
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Table 11. Burst Definition, Addressing Sequence of Sequential and Interleave Mode
Burst Length
4
8
Start Address
A2
A1
A0
X
0
0
X
0
1
X
1
0
X
1
1
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
Sequential
Interleave
0, 1, 2, 3
1, 2, 3, 0
2, 3, 0, 1
3, 0, 1, 2
0, 1, 2, 3, 4, 5, 6, 7
1, 2, 3, 0, 5, 6, 7, 4
2, 3, 0, 1, 6, 7, 4, 5
3, 0, 1, 2, 7, 4, 5, 6
4, 5, 6, 7, 0, 1, 2, 3
5, 6, 7, 4, 1, 2, 3, 0
6, 7, 4, 5, 2, 3, 0, 1
7, 4, 5, 6, 3, 0, 1, 2
0, 1, 2, 3
1, 0, 3, 2
2, 3, 0, 1
3, 2, 1, 0
0, 1, 2, 3, 4, 5, 6, 7
1, 0, 3, 2, 5, 4, 7, 6
2, 3, 0, 1, 6, 7, 4, 5
3, 2, 1, 0, 7, 6, 5, 4
4, 5, 6, 7, 0, 1, 2, 3
5, 4, 7, 6, 1, 0, 3, 2
6, 7, 4, 5, 2, 3, 0, 1
7, 6, 5, 4, 3, 2, 1, 0
z Burst read command
The Burst Read command is initiated by having CS# and CAS# LOW while holding RAS# and WE# HIGH at the
rising edge of the clock. 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 1 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), similar to the existing SDR and DDR SDRAMs. The AL is defined by the Extended Mode Register Set (1)
(EMRS (1)).
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 crosspoint 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.
z Burst write operation
The Burst Write command is initiated by having CS#, CAS# and WE# LOW while holding RAS# HIGH at the
rising edge of the clock. The address inputs determine the starting column address. 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) one 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). 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
the specified AC/DC levels. In differential mode, these timing relationships are measured relative to the
crosspoint 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 20Ω to 10KΩ resistor to insure proper operation.
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z Write data mask
One Write data mask (DM) pin for each 8 data bits (DQ) will be supported on DDR2 SDRAMs, Consistent with
the implementation on DDR SDRAMs. It has identical timings on Write operations as the data bits, and though
used in a uni-directional manner, is internally loaded identically to data bits to insure matched system timing. DM
is not used during read cycles.
z Precharge operation
The Precharge command is used to precharge or close a bank that has been activated. The Precharge
Command is triggered when CS#, RAS# and WE# are LOW and CAS# is HIGH at the rising edge of the clock.
The Precharge Command can be used to precharge each bank independently or all banks simultaneously.
Three address bits A10, BA2, BA1, and BA0 are used to define which bank to precharge when the command is
issued.
Table 12. Bank Selection for Precharge by address bits
A10
BA2
BA1
BA0
Precharged Bank(s)
LOW
LOW
LOW
LOW
Bank 0 only
LOW
LOW
LOW
HIGH
Bank 1 only
LOW
LOW
HIGH
LOW
Bank 2 only
LOW
LOW
HIGH
HIGH
Bank 3 only
LOW
HIGH
LOW
LOW
Bank 4 only
LOW
HIGH
LOW
HIGH
Bank 5 only
LOW
HIGH
HIGH
LOW
Bank 6 only
LOW
HIGH
HIGH
HIGH
Bank 7 only
HIGH
DON’T CARE DON’T CARE DON’T CARE
ALL Banks
z Burst read operation followed by precharge
Minimum Read to precharge command spacing to the same bank = AL + BL/2 + max (RTP, 2) - 2 clocks. For the
earliest possible precharge, the precharge command may be issued on the rising edge which “Additive latency
(AL) + BL/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.
z Burst Write operation followed by precharge
Minimum Write to Precharge command spacing to the same bank = WL + BL/2 + 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, as DDR2 SDRAM does
not support any burst interrupt by a Precharge command. tWR is an analog timing parameter and is not the
programmed value for tWR in the MRS.
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z 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. Auto-precharge also be 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.
z 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 are satisfied. 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 the internal precharge happens
(not at the next rising clock edge after this event). So for BL = 4 the minimum time from Read with AutoPrecharge to the next Activate command becomes AL + tRTP + tRP. For BL = 8 the time from Read with AutoPrecharge to the next Activate command is AL + 2 + tRTP + tRP. Note that both parameters tRTP and tRP have to be
rounded up to the next integer value. 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:
(1) The RAS# precharge time (tRP) has been satisfied from the clock at which the Auto-Precharge begins.
(2) The RAS# cycle time (tRC) from the previous bank activation has been satisfied.
z 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 (tWR). The bank undergoing auto-precharge from the completion of the write burst may be reactivated if the
following two conditions are satisfied.
(1) The data-in to bank activate delay time (WR + tRP) has been satisfied.
(2) The RAS# cycle time (tRC) from the previous bank activation has been satisfied.
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Table 13. Precharge & Auto Precharge Clariification
Minimum Delay between “From
Unit Note
Command” to “To Command”
Precharge (to same Bank as Read)
AL+BL/2+max(RTP,2)-2
Read
tCK 1,2
Precharge All
AL+BL/2+max(RTP,2)-2
Precharge (to same Bank as Read w/AP)
AL+BL/2+max(RTP,2)-2
Read w/AP
tCK 1,2
Precharge All
AL+BL/2+max(RTP,2)-2
Precharge (to same Bank as Write)
WL+BL/2+tWR
tCK
Write
2
Precharge All
WL+BL/2+tWR
Precharge (to same Bank as Write w/AP)
WL+BL/2+tWR
tCK
Write w/AP
2
Precharge All
WL+BL/2+tWR
Precharge (to same Bank as Precharge)
1
Precharge
tCK
2
Precharge All
1
Precharge
1
Precharge All
tCK
2
Precharge All
1
NOTE 1: RTP [cycles] =RU {tRTP [ns]/tCK (avg) [ns]}, where RU stands for round up.
NOTE 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 prechrage period is satisfied after tRP or tRPall(=tRP
for 8 bank device + 1X tCK) depending on the latest precharge command issued to that bank.
From Command
To Command
z Refresh command
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.
When the refresh cycle has completed, all banks of the DDR2 SDRAM will be in the precharged (idle) state. A
delay between the Refresh command (REF) and the next Activate command or subsequent Refresh command
must be greater than or equal to the 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 * tREFI.
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z Self refresh operation
The Self Refresh command can be used to retain data in the DDR2 SDRAM, even if the rest of the system is
powered down. When in the Self Refresh mode, the DDR2 SDRAM retains data without external clocking. The
DDR2 SDRAM device has a built-in timer to accommodate Self Refresh operation. The Self Refresh Command
is defined by having CS#, RAS#, CAS# and CKE# held LOW with WE# HIGH at the rising edge of the clock.
ODT must be turned off before issuing Self Refresh command, by either driving ODT pin LOW or using 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”. For proper Self Refresh operation all power supply pins (VDD, VDDQ, VDDL and VREF) must be at valid
levels. The DRAM initiates a minimum of one refresh command internally within tCKE period once it enters Self
Refresh mode. The clock is internally disabled during Self Refresh Operation to save power. The minimum time
that the DDR2 SDRAM must remain in Self Refresh mode is tCKE. 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.
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.
z Power-Down
Power-down is synchronously entered when CKE is registered LOW along with NOP or Deselect command. No
read or write operation may be in progress when CKE goes LOW. These operations are any of the following:
read burst or write burst and recovery. CKE is allowed to go LOW while any of other operations such as row
activation, precharge or autoprecharge, mode register or extended mode register command time, or autorefresh
is in progress.
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.
If power-down occurs when all banks are precharged, 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. For
Active Power-down two different power saving modes can be selected within the MRS register, address bit A12.
When A12 is set to “LOW” this mode is referred as “standard active power-down mode” and a fast power-down
exit timing defined by the tXARD timing parameter can be used. When A12 is set to “HIGH” this mode is referred
as a power saving “LOW power active power-down mode”. This mode takes longer to exit from the power-down
mode and the tXARDS timing parameter has to be satisfied. Entering power-down deactivates the input and output
buffers, excluding CK, CK#, 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 all other
input signals are “Don’t Care”. Power-down duration is limited by 9 times tREFI of the device.
The power-down state is synchronously exited when CKE is registered HIGH (along with a NOP or Deselect
command). A valid, executable command can be applied with power-down exit latency, tXP, tXARD or tXARDS, after
CKE goes HIGH. Power-down exit latencies are defined in the AC spec table of this data sheet.
z Asynchronous CKE LOW Event
DRAM requires CKE to be maintained “HIGH” for all valid operations as defined in this datasheet. If CKE
asynchronously drops “LOW” during any valid peration DRAM is not guaranteed to preserve the contents of
array. If this event occurs, memory controller must satisfy DRAM timing specification tDelay efore turning off the
clocks. Stable clocks must exist at the input of DRAM before CKE is raised “HIGH” again. DRAM must be fully
re-initialized. DRAM is ready for normal operation after the initialization sequence.
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EtronTech
EM68C08CWAE
z 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 EMRS after precharge power down exit. Depending on new clock frequency an additional
MRS 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.
z No operation command
The No Operation Command should be used in cases when the DDR2 SDRAM is in an idle or a wait state. The
purpose of the No Operation Command (NOP) is to prevent the DDR2 SDRAM from registering any unwanted
commands between operations. A No Operation Command is registered when CS# is LOW with RAS#, CAS#,
and WE# held HIGH at the rising edge of the clock. A No Operation Command will not terminate a previous
operation that is still executing, such as a burst read or write cycle.
z Deselect command
The Deselect Command performs the same function as a No Operation Command. Deselect Command occurs
when CS# is brought HIGH at the rising edge of the clock, the RAS#, CAS#, and WE# signals become don’t
cares.
Rev. 1.1
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EtronTech
EM68C08CWAE
Table 14. Absolute Maximum DC Ratings
Symbol
Parameter
Values
Unit Note
VDD
Voltage on VDD pin relative to Vss
-1.0 ~ 2.3
V
1,3
VDDQ
Voltage on VDDQ pin relative to Vss
-0.5 ~ 2.3
V
1,3
VDDL
Voltage on VDDL pin relative to Vss
-0.5 ~ 2.3
V
1,3
VIN, VOUT Voltage on any pin relative to Vss
- 0.5 ~ 2.3
V
1,4
TSTG Storage temperature
- 55~100
1,2
°C
NOTE1: Stress greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the
devices. 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.
NOTE2: Storage temperature is the case temperature on the center/top side of the DRAM.
NOTE3: When VDD and VDDQ and VDDL are less than 500mV, Vref may be equal to or less than 300mV.
NOTE4: Voltage on any input or I/O may not exceed voltage on VDDQ.
Table 15. Operating Temperature Condition
Symbol
Parameter
Value
Unit Note
-40~95
1,2
TOPER Operating temperature
°C
NOTE1: Operating temperature is the case surface temperature on center/top of the DRAM.
NOTE2: If TC exceeds 85°C, the DRAM must be refreshed externally at 2x refresh. It is required to set tREFI=3.9µs
in auto refresh mode and to set ‘1’ for EMRS (2) bit A7 in self refresh mode.
Table 16. Recommended DC Operating Conditions (SSTL_1.8)
Symbol
Parameter
Min.
Typ.
Max.
Unit Note
VDD
Power supply voltage
1.7
1.8
1.9
V
1
VDDL
Power supply voltage for DLL
1.7
1.8
1.9
V
5
VDDQ
Power supply voltage for I/O Buffer
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
mV
2,3
VTT
Termination voltage
VREF - 0.04
VREF
VREF + 0.04
V
4
NOTE1: There is no specific device VDD supply voltage requirement for SSTL_18 compliance. However under all
conditions VDDQ must be less than or equal to VDD.
NOTE2: 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.
NOTE3: Peak to peak ac noise on VREF may not exceed ±2 % VREF (dc).
NOTE4: VTT of transmitting device must track VREF of receiving device.
NOTE5: VDDQ tracks with VDD, VDDL tracks with VDD. AC parameters are measured with VDD, VDDQ and VDDL tied
together
Rev. 1.1
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EtronTech
EM68C08CWAE
Table 17. Input logic level
Symbol
-18I
Parameter
Min.
VIH (DC) DC Input logic High Voltage
-25I/3I
Max.
Min.
Unit
Max.
VREF + 0.125 VDDQ + 0.3 VREF + 0.125 VDDQ + 0.3
V
VIL (DC) DC Input Low Voltage
-0.3
VREF - 0.125
-0.3
VREF - 0.125
V
VIH (AC) AC Input High Voltage
VREF + 0.2
-
VREF + 0.2
VDDQ+Vpeak
V
-
VREF – 0.2
VssQ –Vpeak
VREF – 0.2
V
0.5
VDDQ+0.6
0.5
VDDQ
V
VIL (AC)
AC Input Low Voltage
VID (AC) AC Differential Voltage
0.5 x VDDQ0.5 x
0.5 x
0.5 x VDDQV
0.175
VDDQ+0.175
0.175
VDDQ+0.175
NOTE1: Refer to Overshoot/undershoot specification for Vpeak value: maximum peak amplitude allowed for
overshoot and undershoot.
VIX (AC) AC Differential crosspoint Voltage
Table 18. AC Input test conditions
Symbol
VREF
Parameter
Value
Input reference voltage
VSWING(max) Input signal maximum peak to peak swing
Unit Note
0.5 x VDDQ
V
1
1.0
V
1
Slew Rate Input signal minimum slew rate
1.0
V/ns 2, 3
NOTE1: Input waveform timing is referenced to the input signal crossing through the VIH /IL (ac) level applied to the
device under test.
NOTE2: 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 .
NOTE3: 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.
Table 19. Differential AC output parameters
Symbol
Value
Parameter
Min.
Unit Note
Max.
Vox(ac) AC Differential Cross Point Voltage
0.5xVDDQ-0.125
0.5xVDDQ+0.125
V
1
NOTE1: 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.
Table 20. AC overshoot/undershoot specification for address and control pins
(A0-A12, BA0-BA2, CS#, RAS#, CAS#, WE#, CKE, ODT)
Parameter
-18I
-25I
-3I
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
Rev. 1.1
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EtronTech
EM68C08CWAE
Table 21. AC overshoot/undershoot specification for clock, data, strobe, and mask pins
(DQ, DQS, DQS#, DM, CK, CK#)
Parameter
-18I
-25I
-3I
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
0.19
0.23
0.23
V-ns
Maximum undershoot area below VSS
0.19
0.23
0.23
V-ns
Table 22. Output AC test conditions
Symbol
Parameter
Value
VOTR
Output timing measurement reference level
0.5xVDDQ
Unit Note
V
1
NOTE1: The VDDQ of the device under test is referenced.
Table 23. Output DC current drive
Symbol
IOH(dc)
Parameter
Output minimum source DC current
SSTL_18
Unit Note
-13.4
mA 1, 3, 4
IOL(dc)
Output minimum sink DC current
13.4
mA 2, 3, 4
NOTE1: VDDQ = 1.7 V; VOUT = 1420 mV. (VOUT - VDDQ) /IOH must be less than 21 Ω for values of VOUT between VDDQ
and VDDQ - 280 mV.
NOTE2: VDDQ = 1.7 V; VOUT = 280 mV. VOUT/IOL must be less than 21 Ω for values of VOUT between 0 V and 280 mV.
NOTE3: The dc value of VREF applied to the receiving device is set to VTT
NOTE4: The values of IOH (dc) and IOL (dc) are based on the conditions given in Notes 1 and 2. They are used to
test device drive current capability to ensure VIH min plus a noise margin and VIL max minus a noise
margin are delivered to an SSTL_18 receiver. The actual current values are derived by shifting the desired
driver operating point (see JEDEC standard: Section 3.3 of JESD8-15A) along a 21 Ω load line to define a
convenient driver current for measurement.
Table 24. Capacitance (VDD = 1.8V, f = 1MHz, TOPER = 25 °C)
Symbol
CIN
CCK
CI/O
DCIN
DCCK
DCIO
DDR2-1066/800
Parameter
Input Capacitance : Command and Address
Input Capacitance (CK, CK#)
DM, DQ, DQS Input/Output Capacitance
Delta Input Capacitance: Command and Address
Delta Input Capacitance: CK, CK#
Delta Input/Output Capacitance: DM, DQ, DQS
Min.
1.0
1.0
2.5
-
Max.
1.75
2.0
3.5
0.25
0.25
0.5
DDR2-667
Min.
1.0
1.0
2.5
-
Max.
2.0
2.0
3.5
0.25
0.25
0.5
Unit
pF
pF
pF
pF
pF
pF
NOTE: These parameters are periodically sampled and are not 100% tested.
Rev. 1.1
23
Jul. /2014
EtronTech
EM68C08CWAE
Table 25. IDD specification parameters and test conditions
(VDD = 1.8V ± 0.1V, TOPER = -40~95°C)
Parameter & Test Condition
Operating one bank active-precharge current:
tCK =tCK (min), tRC = tRC (min), tRAS = tRAS(min); CKE is HIGH, CS# is
HIGH between valid commands; Address bus inputs are SWITCHING;
Data bus inputs are SWITCHING
Operating one bank active-read-precharge current:
IOUT = 0mA; BL = 4, CL = CL (min), AL = 0; tCK = tCK (min),tRC = tRC (min),
tRAS = tRAS(min), tRCD = tRCD (min);CKE is HIGH, CS# is HIGH between
valid commands;Address bus inputs are switching; Data pattern is same
as IDD4W
Precharge power-down current:
All banks idle;tCK =tCK (min); CKE is LOW; Other control and address bus
inputs are STABLE; Data bus inputs are FLOATING
Precharge quiet standby current:
All banks idle; tCK =tCK (min); CKE is HIGH, CS# is HIGH; Other control
and address bus inputs are STABLE; Data bus inputs are FLOATING
Precharge standby current:
All banks idle; tCK = tCK (min); CKE is HIGH, CS# is HIGH; Other control
and address bus inputs are SWITCHING; Data bus inputs are
SWITCHING
Active power-down current:
MRS(A12)=0
All banks open; tCK =tCK (min); CKE is LOW; Other
control and address bus inputs are STABLE; Data bus
MRS(A12)=1
inputs are FLOATING
Active standby current:
All banks open; tCK = tCK(min), tRAS = tRAS (max), tRP = tRP (min); CKE is
HIGH, CS# is HIGH between valid commands; Other control and address
bus inputs are SWITCHING; Data bus inputs are SWITCHING
Operating burst write current:
All banks open,continuous burst writes; BL = 4, CL = CL (min), AL = 0;
tCK= tCK (min), tRAS = tRAS (max), tRP = tRP (min); CKE is HIGH, CS# is
HIGH between valid commands; Address bus inputs are switching; Data
bus inputs are switching
Operating burst read current:
All banks open, continuous burst reads, IOUT = 0mA; BL = 4, CL = CL
(min), AL = 0; tCK = tCK (min), tRAS = tRAS (max), tRP = tRP (min); CKE is
HIGH, CS# is HIGH between valid commands; Address bus inputs are
SWITCHING; Data bus inputs are SWITCHING
Burst refresh current:
tCK = tCK (min); refresh command at every tRFC (min) interval; CKE is
HIGH, CS# is HIGH between valid commands; Other control and address
bus inputs are SWITCHING; Data bus inputs are SWITCHING
Self refresh current:
CK and CK# at 0V; CKE ≤ 0.2V;Other control and address bus inputs
are FLOATING; Data bus inputs are FLOATING
Operating bank interleave read current:
All bank interleaving reads, IOUT= 0mA; BL = 4, CL = CL (min), AL =tRCD
(min) - 1 x tCK (min); tCK = tCK (min), tRC = tRC (min), tRRD = tRRD (min), tRCD =
tRCD (min); CKE is HIGH, CS# is HIGH between valid commands;
Address bus inputs are STABLE during DESELECTs.Data pattern is
same as IDD4R
Rev. 1.1
-18I
-25I
Max.
-3I
Unit
IDD0
65
55
46
mA
IDD1
80
70
58
mA
IDD2P
10
9
9
mA
IDD2Q
23
18
15
mA
IDD2N
30
25
21
mA
25
23
23
mA
20
16
16
mA
IDD3N
37
32
27
mA
IDD4W
150
115
96
mA
IDD4R
135
100
84
mA
IDD5
125
100
84
mA
IDD6
10
9
9
mA
IDD7
215
180
150
mA
Symbol
24
IDD3P
Jul. /2014
EtronTech
EM68C08CWAE
Table 26. Electrical Characteristics and Recommended A.C. Operating Conditions
(VDD = 1.8V ± 0.1V, TOPER = -40~95°C)
Symbol
-18I
Parameter
CL=4
tCK(avg)
tCH(avg)
tCL(avg)
WL
tDQSS
tDSS
tDSH
CL=5
CL=6
CL=7
Average clock HIGH pulse width
Average Clock LOW pulse width
Write command to DQS associated clock
edge
DQS latching rising transitions to
associated clock edges
DQS falling edge to CK setup time
DQS falling edge hold time from CK
Average clock period
-25I
-3I
Unit
Specific
Notes
8
ns
15, 33,
34
8
8
0.52
0.52
ns
ns
ns
tCK
tCK
Min.
Max.
Min
Max.
Min.
Max.
3.75
7.5
3.75
8
3.75
3
2.5
1.875
0.48
0.48
7.5
7.5
7.5
0.52
0.52
2.5
2.5
0.48
0.48
8
8
0.52
0.52
3
3
0.48
0.48
RL-1
RL-1
RL-1
tCK
-0.25
0.25
-0.25
0.25
-0.25
0.25
tCK
28
0.2
0.2
-
0.2
0.2
-
0.2
0.2
-
tCK
tCK
28
tDQSH
DQS input HIGH pulse width
0.35
-
0.35
-
0.35
-
tCK
tDQSL
tWPRE
tWPST
DQS input LOW pulse width
Write preamble
Write postamble
0.35
0.35
0.4
0.6
0.35
0.35
0.4
0.6
0.35
0.35
0.4
0.6
tCK
tCK
tCK
tIS(base)
Address and Control input setup time
0.125
-
0.175
-
0.2
-
ns
tIH(base)
Address and Control input hold time
0.2
-
0.25
-
0.275
-
ns
tIPW
Control & Address input pulse width for
each input
0.6
-
0.6
-
0.6
-
tCK
tDS(base)
DQ & DM input setup time
0
-
0.05
-
0.1
-
ns
tDH(base)
DQ & DM input hold time
0.075
-
0.125
-
0.175
-
ns
tDIPW
tAC
tDQSCK
DQ and DM input pulse width for each input
0.35
0.35
0.35
DQ output access time from CK, CK#
-0.35
0.35
-0.4
0.4
-0.45
0.45
DQS output access time from CK, CK#
-0.325
0.325
-0.35
0.35
-0.4
0.4
Data-out high-impedance time from CK,
tAC(max)
tAC(max)
tAC(max)
CK#
DQS(DQS#) low-impedance time from CK,
tAC(min) tAC(max) tAC(min) tAC(max) tAC(min) tAC(max)
CK#
DQ low-impedance time from CK, CK#
2tAC(min) tAC(max) 2tAC(min) tAC(max) 2tAC(min) tAC(max)
DQS-DQ skew for DQS and associated DQ
0.175
0.2
0.24
signals
min
min
min
CK half pulse width
(tCH,tCL)
(tCH,tCL)
(tCH,tCL)
DQ hold skew factor
0.25
0.3
0.34
DQ/DQS output hold time from DQS
tHP -tQHS
tHP -tQHS
tHP -tQHS
Read preamble
0.9
1.1
0.9
1.1
0.9
1.1
Read postamble
0.4
0.6
0.4
0.6
0.4
0.6
Active to active command period
7.5
7.5
7.5
Four Activate Window
35
35
37.5
CAS# to CAS# command delay
2
2
2
Write recovery time
15
15
15
Auto Power write recovery + precharge
WR + tRP
WR + tRP
WR + tRP
time
Internal Write to Read Command Delay
7.5
7.5
7.5
Internal read to precharge command delay
7.5
7.5
7.5
CKE minimum pulse width
3
3
3
-
tHZ
tLZ(DQS)
tLZ(DQ)
tDQSQ
tHP
tQHS
tQH
tRPRE
tRPST
tRRD
tFAW
tCCD
tWR
tDAL
tWTR
tRTP
tCKE
Rev. 1.1
34, 35
34, 35
25
10
5, 7, 9,
22, 27
5, 7, 9,
23, 27
6-8, 20,
26, 29
6-8, 21,
26, 29
tCK
ns
ns
38
38
ns
18, 38
ns
18, 38
ns
18, 38
ns
13
ns
ns
ns
tCK
tCK
ns
ns
tCK
ns
11, 12,
35
12, 36
37
19, 39
19, 40
4, 30
4, 30
30
ns
14, 31
ns
ns
tCK
3, 24, 30
3, 30
25
Jul. /2014
EtronTech
EM68C08CWAE
tAOND
Exit self refresh to non-read command
delay
Exit self refresh to a read command
Exit precharge power down to any
command
Exit active power down to read command
Exit active power down to read
command(slow exit, lower power)
ODT turn-on delay
tAON
ODT turn-on
tAC(min)
tAONPD
ODT turn-on (Power-Down mode)
tAC(min)+
2
tAOFD
ODT turn-off delay
tAOF
ODT turn-off
tAC(min)
tAOFPD
ODT turn-off (Power-Down mode)
tAC(min)+
2
tANPD
tAXPD
tMRD
tMOD
tRFC
ODT to power down entry latency
ODT power down exit latency
Mode register set command cycle time
MRS command to ODT update delay
Minimum time clocks remains ON after
CKE asynchronously drops LOW
Refresh to active/Refresh command time
tREFI
Average periodic
refesh interval
tRCD
tRP
tRC
tRAS
RAS# to CAS# Delay time
Row precharge Delay time
Row cycle Delay time
Row active Delay time
tXSNR
tXSRD
tXP
tXARD
tXARDS
tDelay
Rev. 1.1
tRFC+10
-
tRFC+10
-
tRFC+10
-
ns
200
-
200
-
200
-
tCK
3
-
2
-
2
-
tCK
2
-
2
-
2
-
tCK
1
10-AL
-
8-AL
-
7-AL
-
tCK
1, 2
2
2
tAC(max)
+2.575
3 tCK
+tAC(max
)+1
2.5
tAC(max)
+0.6
2.5 tCK
+tAC(max
)+1
12
2
2
tAC(max)
+0.7
2 tCK
+tAC(max
)+1
2.5
tAC(max)
+0.6
2.5 tCK
+tAC(max
)+1
12
2
2
tAC(max)
+0.7
2 tCK
+tAC(max
)+1
2.5
tAC(max)
+0.6
2.5 tCK
+tAC(max
)+1
12
tCK
16
ns
6, 16, 38
2.5
4
11
2
0
tIS+ tCK
+tIH
127.5
tAC(min)
tAC(min)+
2
2.5
tAC(min)
tAC(min)+
2
-
3
8
2
0
tIS+ tCK
+tIH
127.5
-
tAC(min)
tAC(min)+
2
2.5
tAC(min)
tAC(min)+
2
-
3
8
2
0
tIS+ tCK
+tIH
127.5
-
ns
tCK
ns
17, 42
17, 41,
42
ns
tCK
tCK
tCK
ns
30
-
ns
15
-
ns
43
µs
43
@ -40℃ to +85℃
-
7.8
-
7.8
-
7.8
@ +85℃ to 95℃
-
3.9
-
3.9
-
3.9
13.125
13.125
58.125
45
70K
12.5
12.5
57.5
45
70K
15
15
60
45
70K
26
30
ns
ns
ns
ns
Jul. /2014
EtronTech
EM68C08CWAE
General notes, which may apply for all AC parameters:
NOTE 1: DDR2 SDRAM AC timing reference load
The below figure represents the timing reference load used in defining the relevant timing parameters of the part.
It is not intended to be either a precise representation of the typical system environment or a depiction of the actual
load presented by a production tester.
Figure 5. AC timing reference load
VDDQ
DQ
DQS
DQS#
RDQS
RDQS#
DUT
Ouput
25Ω
VTT=VDDQ/2
Timing reference
point
The output timing reference voltage level for single ended signals is the crosspoint with VTT. The output timing
reference voltage level for differential signals is the crosspoint of the true (e.g. DQS) and the complement (e.g.
DQS#) signal.
NOTE 2: 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. CK – CK#) slew rate for rising edges is
measured from CK – CK# = - 250 mV to CK -CK# = + 500 mV (+ 250 mV to - 500 mV for falling edges).
c) VID is the magnitude of the difference between the input voltage on CK and the input voltage on CK#, or
betweenDQS and DQS# for differential strobe.
NOTE 3: DDR2 SDRAM output slew rate test load
Output slew rate is characterized under the test conditions as bellow
Figure 6. Slew rate test load
VDDQ
DUT
DQ
DQS
DQS#
RDQS
RDQS#
Ouput
25Ω
VTT=VDDQ/2
Test point
Rev. 1.1
27
Jul. /2014
EtronTech
EM68C08CWAE
NOTE 4: 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 crosspoint 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
NOTE 5: AC timings are for linear signal transitions.
NOTE 6:All voltages are referenced to VSS.
NOTE 7: These parameters guarantee device behavior, but they are not necessarily tested on each device.They
may be guaranteed by device design or tester correlation
NOTE 8: 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.
Specific notes for dedicated AC parameters
NOTE 1: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 where a lower power value is defined by each vendor data sheet.
NOTE 2: AL=Additive Latency.
NOTE 3:This is a minimum requirement. Minimum read to precharge timing is AL+BL/2 provided that the tRTP and
tRAS (min) have been satisfied.
NOTE 4: A minimum of two clocks (2* tCK) is required irrespective of operating frequency.
NOTE 5: Timings are specified with command/address input slew rate of 1.0 V/ns.
NOTE 6:Timings are specified with DQs, DM, and DQS’s (DQS/RDQS in single ended mode) input slew rate of
1.0V/ns.
NOTE 7:Timings are specified with CK/CK# 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 and a slew rate of 1 V/ns in single
ended mode.
NOTE 8:Data setup and hold time derating.
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 ∆tDS and ∆tDH derating value respectively.
Example: tDS (total setup time) =tDS (base) + ∆tDS.For slew rates in between the values listed in Tables 27, the
derating values may obtained by linear interpolation.These values are typically not subject to production test.
They are verified by design and characterization.
Table 27. DDR2-667/800/1066 tDS/tDH derating with differential data strobe
△tDS, △tDH derating values for DD2-667/800/1066 (All units in ‘ps’; the note applies to the entire table)
DQS,DQS# Differential Slew Rate
2.8 V/ns
2.4 V/ns
2.0 V/ns
1.8 V/ns
1.6 V/ns
1.4 V/ns
1.2 V/ns
1.0 V/ns
DQ
Slew
Rate
V/ns
0.8 V/ns
△tDS
△tDH
△tDS
△tDH
△tDS
△tDH
△tDS
△tDH
△tDS
△tDH
△tDS
△tDH
△tDS
△tDH
△tDS
△tDH
△tDS
2.0
100
63
100
63
100
63
-
-
-
-
-
-
-
-
-
-
-
-
1.5
67
42
67
42
67
42
79
54
-
-
-
-
-
-
-
-
-
-
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
Rev. 1.1
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△tDH
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EM68C08CWAE
NOTE 9:tIS and tIH (input setup and hold) derating
For all input signals the total tIS (setup time) and tIH (hold time) required is calculated by adding the data sheet
tIS(base) and tIH(base) value to the ∆tIS and ∆tIH derating value respectively.
Example: tIS (total setup time) = tIS(base) + ∆tIS
For slew rates in between the values listed in Tables 28, the derating values may obtained by linear
interpolation.These values are typically not subject to production test. They are verified by design and
characterization
Table 28. Derating values for DDR2-667/800/1066
Command/
Address Slew rate
(V/ns)
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.25
0.2
0.15
0.1
△tIS and △tIH Derating Values for DDR2-667/800/1066
CK,CK# Differential Slew Rate
2.0 V/ns
1.5 V/ns
1.0 V/ns
△tIS
△tIH
△tIS
△tIH
△tIS
△tIH
+150
+94
+180
+124
+210
+154
+143
+89
+173
+119
+203
+149
+133
+83
+163
+113
+193
+143
+120
+75
+150
+105
+180
+135
+100
+45
+130
+75
+160
+105
+67
+21
+97
+51
+127
+81
0
0
+30
+30
+60
+60
-5
-14
+25
+16
+55
+46
-13
-31
+17
-1
+47
+29
-22
-54
+8
-24
+38
+6
-34
-83
-4
-53
+26
-23
-60
-125
-30
-95
0
-65
-100
-188
-70
-158
-40
-128
-168
-292
-138
-262
-108
-232
-200
-375
-170
-345
-140
-315
-325
-500
-295
-470
-265
-440
-517
-708
-487
-678
-457
-648
-1000
-1125
-970
-1095
-940
-1065
Units
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
Notes
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
NOTE 10: The maximum limit for this parameter is not a device limit. The device will operate with a greater value
for this parameter, but system performance (bus turnaround) will degrade accordingly.
NOTE 11: MIN (tCL, tCH) refers to the smaller of the actual clock LOW time and the actual clock HIGH time as
provided to the device (i.e. this value can be greater than the minimum specification limits for tCL and tCH).
NOTE 12: tQH = tHP – tQHS, where:
tHP = minimum half clock period for any given cycle and is defined by clock HIGH or clock LOW (tCH, tCL). tQHS
accounts for:
1) The pulse duration distortion of on-chip clock circuits; 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, separately, due to data pin skew and output pattern effects, and p-channel to nchannel variation of the output drivers.
NOTE 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.
NOTE 14: tDAL = WR + RU{ tRP[ns] / tCK[ns] }, where RU stands for round up.WR refers to the tWR parameter stored
in the MRS. For tRP, if the result of the division is not already an integer, round up to the next highest integer.
tCK refers to the application clock period.
NOTE 15: 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.
NOTE 16: 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 measured 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.
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EM68C08CWAE
NOTE 17: 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 differently per speed
bin. For DDR2-667/800/1066, if tCK (avg) = 2.5 ns is assumed, tAOFD is 1.25 ns (= 0.5 x 2.5 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.
NOTE 18: 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).
NOTE 19: 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). The actual voltage measurement points are
not critical as long as the calculation is consistent.
NOTE 20: Input waveform timing tDS with differential data strobe enabled MR[bit10]=0, is 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.
NOTE 21: Input waveform timing tDH with differential data strobe enabled MR[bit10]=0, is 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.
NOTE 22: Input waveform timing is referenced from the input signal crossing at the VIH(ac) level for a rising signal
and VIL(ac) for a falling signal applied to the device under test.
NOTE 23: Input waveform timing is referenced from the input signal crossing at the VIL(dc) level for a rising signal
and VIH(dc) for a falling signal applied to the device under test.
NOTE 24: tWTR is at lease two clocks (2 x tCK ) independent of operation frequency.
NOTE 25: 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.
NOTE 26: 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.
NOTE 27: 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 (CK/CK#) 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.
NOTE 28: These parameters are measured from a data strobe signal (DQS) crossing to its respective clock signal
(CK/CK#) 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.
NOTE 29: These parameters are measured from a data signal (DM, DQ0, DQ1, etc.) transition edge to its
respective data strobe signal (DQS/ DQS#) crossing.
NOTE 30: 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.
NOTE 31: tDAL [tCK] = WR [tCK] + tRP [tCK] = WR + RU {tRP [ps] / tCK(avg) [ps] }, where WR is the value programmed
in the mode register set.
NOTE 32: New units, ‘tCK(avg)’ is introduced in DDR2-667, DDR2-800 and DDR2-1066. Unit ‘tCK(avg)’ represents
the actual tCK(avg) of the input clock under operation.
NOTE 33: Input clock jitter spec parameter. These parameters and the ones in the table below are referred to as
'input clock jitter spec parameters' and these parameters apply to DDR2-667, DDR2-800 and DDR2-1066.
The jitter specified is a random jitter meeting a Gaussian distribution.
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EM68C08CWAE
Table 29. Input clock jitter spec parameter
Parameter
Symbol
Clock period jitter
Clock period jitter during DLL locking
period
Cycle to cycle clock period jitter
Cycle to cycle clock period jitter during
DLL locking period
Cumulative error across 2 cycles
Cumulative error across 3 cycles
Cumulative error across 4 cycles
Cumulative error across 5 cycles
-18I
-25I
-3I
Min. Max. Min. Max. Min. Max.
Units Notes
tJIT (per)
-90
90
-100
100
-125
125
ps
33
tJIT (per,lck)
-80
80
-80
80
-100
100
ps
33
tJIT (cc)
-180
180
-200
200
-250
250
ps
33
tJIT (cc,lck)
-160
160
-160
160
-200
200
ps
33
tERR (2per)
-132
132
-150
150
-175
175
ps
33
tERR (3per)
-157
157
-175
175
-225
225
ps
33
tERR (4per)
-175
175
-200
200
-250
250
ps
33
tERR (5per)
-188
188
-200
200
-250
250
ps
33
-250
250
-300
300
-350
350
ps
33
-425
425
-450
450
-450
450
ps
33
-75
75
-100
100
-125
125
ps
33
Cumulative error across n cycles, n=6...10,
tERR (6-10per)
inclusive
Cumulative error across n cycles,
tERR (11-50per)
n=11...50, inclusive
Duty cycle jitter
tJIT (duty)
NOTE 34: 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
andmax of SPEC values are to be used for calculations in the table below.)
Table 30. Absolute clock period average values
Parameter
Absolute clock period
Symbol
tCK (abs)
Min.
tCK(avg),min + tJIT(per),min
Max.
tCK(avg),max + tJIT(per),max
Unit
ps
Absolute clock HIGH pulse width
tCH (abs)
tCL (abs)
tCH(avg),max * tCK(avg),max +
tJIT(duty),max
tCL(avg), max * tCK(avg),max +
tJIT(duty), max
ps
Absolute clock LOW pulse width
tCH(avg),min * tCK(avg),min +
tJIT(duty),min
tCL(avg),min * tCK(avg),min +
tJIT(duty),min
ps
NOTE 35: 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;
NOTE 36: 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 pchannel to n-channel variation of the output drivers
Rev. 1.1
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EM68C08CWAE
NOTE 37: 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.}
NOTE 38: 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.)
NOTE 39: 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.)
NOTE 40: 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.)
NOTE 41: 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.)
NOTE 42: For tAOFD of DDR2-667/800/1066, the 1/2 clock of tCK in the 2.5 x tCK 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.
NOTE 43: If refresh timing is violated, data corruption may occur and the data must be re-writtern with valid data
before a valid READ can be executed.
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EM68C08CWAE
Timing Waveforms
Figure 7. Initialization sequence after power-up
tCH tCL
CK
CK#
tIS
CKE
tIS
ODT
EMR
S
PRE
ALL
NOP
Command
tRP
400ns
tMRD
DLL
ENABLE
PRE
ALL
MRS
tMRD
REF
tRP
REF
tRFC
tRFC
DLL
RESET
EMR
S
EMR
S
MRS
tMRD
min 200 Cycle
Follow OCD Flowchart
ANY
CMD
t
OIT
OCD
CAL.MOD
E EXIT
OCD
Default
NOTE 1: To guarantee ODT off, VREF must be valid and a LOW level must be applied to the ODT pin.
Figure 8. ODT update delay timing-tMOD
CMD
EMRS
NOP
NOP
NOP
NOP
NOP
CK#
CK
ODT
tAOFD
Rtt
tMOD, min
tIS
tMOD, max
Old setting
Updating
New setting
NOTE 1: 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.
then the ODT is ready for normal operation with the new setting, and the ODT signal may be raised again to turned
on the ODT.
NOTE 2: EMRS command directed to EMR(1), which updates the information in EMR(1)[A6,A2], i.e. Rtt (Nominal).
NOTE 3: "setting" in this diagram is the Register and I/O setting, not what is measured from outside.
Figure 9. ODT update delay timing-tMOD, as measured from outside
CK#
CK
CMD
EMRS
NOP
ODT
NOP
NOP
tIS
tAOFD
Rtt
NOP
NOP
tAOND
tMOD, max
New setting
Old setting
NOTE 1: EMRS command directed to EMR(1), which updates the information in EMR(1)[A6,A2], i.e. Rtt (Nominal).
NOTE 2: "setting" in this diagram is measured from outside.
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EM68C08CWAE
Figure 10. ODT timing for active standby mode
T0
T1
T3
T2
T4
T5
T6
CK#
CK
tIS
CKE
tIS
tIS
VIH(ac)
VIL(ac)
ODT
tAOND
Internal
Term Res.
tAOFD
RTT
tAON,min
tAOF,min
tAON,max
tAOF,max
Figure 11. ODT timing for power-down mode
T0
T1
T3
T2
T4
T5
T6
CK#
CK
CKE
tIS
tIS
VIH(AC)
VIL(AC)
ODT
tAOFPD,max
tAOFPD,min
Internal
Term Res.
Rev. 1.1
RTT
tAONPD,min
tAONPD,max
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EM68C08CWAE
Figure 12. ODT timing mode switch at entering power-down mode
T-5
CK#
T-4
T-3
T-2
CK
T-1
tANPD
T0
T1
T2
T3
T4
tIS
CKE
Entering Slow Exit Active Power Down Mode or Precharge Power Down Mode.
ODT
tIS
VIL(ac)
tAOFD
Internal
Term Res.
Active & Standby mode
timings to be applied.
RTT
tIS
ODT
VIL(ac)
Power Down mode
timings to be applied.
tAOFPD max
Internal
Term Res.
RTT
tIS
VIH(ac)
ODT
tAOND
RTT
Internal
Term Res.
VIH(ac)
ODT
tIS
tAONPD max
RTT
Internal
Term Res.
Rev. 1.1
Active & Standby mode
timings to be applied.
35
Power Down mode
timings to be applied.
Jul. /2014
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EM68C08CWAE
Figure 13.ODT timing mode switch at exit power-down mode
T0
CK#
CK
VIH(ac)
T1
T4
T5
T6
T7
T8
T9
T10
T11
tAXPD
tIS
CKE
Exiting from Slow Active Power Down Mode or Precharge power Down Mode.
tIS
ODT
VIL(ac)
tAOFD
Active & Standby mode
timings to be applied.
Internal
Term Res.
RTT
tIS
ODT
Power Down mode
timings to be applied.
VIL(ac)
tAOFPD max
Internal
Term Res.
RTT
tIS
VIH(ac)
Active & Standby mode
timings to be applied.
ODT
tAOND
RTT
Internal
Term Res.
VIH(ac)
Power Down mode
timings to be applied.
ODT
tIS
tAONPD max
Internal
Term Res.
RTT
Figure 14. Bank activate command cycle (tRCD=3, AL=2, tRP=3, tRRD=2, tCCD=2)
T0
T1
T3
T2
Tn
Tn+1
Tn+2
Tn+3
CK#
CK
Internal RAS# - CAS# delay (>=tRCD min)
ADDRESS
Bank A
Row Addr.
tRCD = 1
Bank A
Col. Addr.
Bank A
Activate
Bank A
Addr.
Bank B
Addr.
Bank A
Row Addr.
Bank A
Precharge
Bank B
Precharge
Bank A
Activate
CAS# - CAS# delay time (tCCD)
Additive latency delay (AL)
Read Begins
RAS# - RAS# delay time (>=tRRD)
COMMAND
Bank B
Col. Addr
Bank B
Row Addr.
Bank A
Post CAS#
Read
Bank B
Activate
Bank B
Post CAS#
Read
Bank precharge time (>=tRP)
Bank Active (>=tRAS)
RAS# Cycle time (>=tRC)
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Figure 15. Posted CAS# operation: AL=2
Read followed by a write to the same bank
-1
0
1
2
Active
A-Bank
Read
A-Bank
3
4
5
6
7
8
9
10
11
12
11
12
CK#
CK
CMD
Write
A-Bank
AL=2
WL=RL-1=4
CL=3
DQS
DQS#
>=tRCD
RL=AL+CL=5
DQ
Dout 0 Dout 1 Dout 2 Dout 3
Din 0
Din 1
Din 2
Din 3
[ AL=2 and CL=3, RL= (AL+CL)=5, WL= (RL-1)=4, BL=4]
Figure 16. Posted CAS# operation: AL=0
Read followed by a write to the same bank
-1
0
1
2
3
4
5
6
7
8
9
10
CK#
CK
AL=0
CMD
Active
A-Bank
Write
A-Bank
Read
A-Bank
CL=3
DQS
DQS#
WL=RL-1=2
>=tRCD
RL=AL+CL=3
DQ
Dout 0 Dout 1 Dout 2 Dout 3
Din 0
Din 1
Din 2
Din 3
[ AL=0 and CL=3, RL= (AL+CL)=3, WL= (RL-1)=2, BL=4]
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EM68C08CWAE
Figure 17. Data output (read) timing
CK#
CK
DQS
DQS#
DQ
tCH
tCL
CK
DQS#
DQS
tRPRE
tRPST
tDQSQ max
Q
Q
Q
Q
tDQSQ max
tQH
tQH
Figure 18. Data input (write) timing
tDQSH
DQS#
tDQSL
DQS
DQS#
DQS
tWPRE
DQ
tWPSL
VIH(ac)
D
VIL(ac)
tDS
DM
Rev. 1.1
VIH(dc)
D
D
VIL(dc)
tDH
tDS
tDH
VIH(dc)
VIH(ac)
DMin
D
DMin
DMin
VIL(ac)
38
DMin
VIL(dc)
Jul. /2014
EtronTech
EM68C08CWAE
Figure 19. Burst read operation: RL=5 (AL=2, CL=3, BL=4)
T0
CK#
CK
CMD
T1
Posted CAS#
READ A
NOP
T2
T3
NOP
T4
NOP
T5
NOP
T6
NOP
T7
NOP
T8
NOP
NOP
=< tDQSCK
DQS
DQS#
AL=2
CL=3
RL=5
DQs
Dout A0
Dout A1
Dout A2
Dout A3
Figure 20. Burst read operation: RL=3 (AL=0, CL=3, BL=8)
CK#
CK
T0
CMD
READ A
T1
NOP
T2
T3
NOP
T4
NOP
T5
NOP
T6
NOP
T7
NOP
T8
NOP
NOP
=< tDQSCK
DQS
DQS#
CL=3
RL=3
DQs
Dout A0
Dout A1
Dout A2
Dout A3
Dout A4
Dout A5
Dout A6
Dout A7
Figure 21. Burst read followed by burst write: RL=5, WL= (RL-1) =4, BL=4
CK#
CK
CMD
T0
Post CAS#
READ A
T1
NOP
Tn-1
NOP
Tn
Tn+1
Post CAS#
WRITE A
Tn+2
NOP
Tn+3
NOP
NOP
Tn+4
Tn+5
NOP
NOP
tRTW (Read to Write turn around time)
DQS
DQS#
RL=5
WL = RL-1 = 4
DQs
Dout A0
Dout A1
Dout A2
Dout A3
Din A0
Din A1
Din A2
Din A3
NOTE : The minimum time from the burst read command to the burst write command is defined by a read-to-writeturn-around-time, which is 4 clocks in case of BL = 4 operation, 6 clocks in case of BL = 8 operation.
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EM68C08CWAE
Figure 22. Seamless burst read operation: RL=5, AL=2, CL=3, BL=4
T1
T0
T2
T3
T4
T5
T6
T7
T8
CK#
CK
Post CAS#
READ A
CMD
DQS
DQS#
NOP
Post CAS#
READ B
NOP
AL=2
NOP
NOP
NOP
NOP
NOP
CL=3
RL=5
DQs
Dout A0
Dout A1
Dout A2
Dout A3
Dout B0
Dout B1
Dout B2
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.
Figure 23. Read burst interrupt timing: (CL=3, AL=0, RL=3, BL=8)
CK#
CK
CMD
Read A
NOP
Read B
NOP
NOP
NOP
NOP
NOP
NOP
NOP
DQS
DQS#
DQs
A0
A1
A2
A3
B0
B1
B2
B3
B4
B5
B6
B7
NOTE 1: Read burst interrupt function is only allowed on burst of 8. Burst interrupt of 4 is prohibited.
NOTE 2: Read burst of 8 can only be interrupted by another Read command. Read burst interruption by Write
command or Precharge command is prohibited.
NOTE 3: Read burst interrupt must occur exactly two clocks after previous Read command. Any other Read burst
interrupt timings are prohibited.
NOTE 4: Read burst interruption is allowed to any bank inside DRAM.
NOTE 5: Read burst with Auto Precharge enabled is not allowed to interrupt.
NOTE 6: Read burst interruption is allowed by another Read with Auto Precharge command.
NOTE 7: All command timings are referenced to burst length set in the mode register. They are not referenced to
actual burst. For example, 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).
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EM68C08CWAE
Figure 24. Burst write operation: RL=5 (AL=2, CL=3), WL=4, BL=4
CK#
CK
CMD
T0
T1
Posted CAS#
WRITE A
T2
NOP
T3
NOP
T4
NOP
Case 1: with tDQSS (max)
DQS
DQS#
T5
NOP
NOP
tDQSS
tDSS tDQSS
T6
T7
NOP
tDSS
NOP
Precharge
Completion of the
Burst Write
WL = RL-1 =4
>=tWR
DQs
DNA0
Case 2: with tDQSS (min)
DQS
DQS#
Tn
tDQSS tDSH
DNA1
DNA2 DNA3
tDQSS tDSH
>=tWR
WL = RL-1 =4
DQs
DNA0
DNA1
DNA2 DNA3
Figure 25. Burst write operation: RL=3 (AL=0, CL=3), WL=2, BL=4
T0
T1
T2
T3
T4
T5
Tm
Tm+1
Tn
CK#
CK
CMD
WRITE A
NOP
NOP
NOP
NOP
<=tDQSS
DQS
DQS#
DQs
Rev. 1.1
NOP
>=tWR
DNA1
NOP
Bank A
Activate
Completion of the
Burst Write
WL = RL-1 =2
DNA0
Precharge
>=tRP
DNA2 DNA3
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EM68C08CWAE
Figure 26. Burst write followed by burst read:
RL=5 (AL=2, CL=3, WL=4, tWTR=2, BL=4)
CK#
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
CK
Write to Read = CL-1+BL/2+tWTR
CKE
DQS
DQS#
NOP
NOP
NOP
Post CAS#
READ A
NOP
NOP
NOP
NOP
NOP
DQS#
DQS
WL = RL-1 = 4
AL=2
CL=3
RL=5
>=tWTR
DQ
DNA0
DNA1
DNA2 DNA3
DOUT A0
NOTE : The minimum number of clock from the burst write command to the burst read command is [CL-1 + BL/2 + tWTR].
This tWTR is not a write recovery time (tWR) but the time required to transfer the 4 bit write data from the input buffer into
sense amplifiers in the array. tWTR is defined in the timing parameter table of this standard.
Figure 27. Seamless burst write operation RL=5, WL=4, BL=4
CK#
T0
T1
T2
T3
T4
T5
T6
T7
T8
CK
CMD
DQS
DQS#
Post CAS#
Write A
NOP
Post CAS#
Write B
NOP
NOP
NOP
NOP
NOP
NOP
DQS#
DQS
WL = RL-1 = 4
DQ
DNA0
DNA1
DNA2 DNA3 DNB0
DNB1
DNB2 DNB3
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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EM68C08CWAE
Figure 28. Write burst interrupt timing: (CL=3, AL=0, RL=3, WL=2, BL=8)
CK#
CK
CMD
NOP
Write A
NOP
Write B
NOP
NOP
NOP
NOP
NOP
NOP
DQS
DQS#
DQs
A0
A1
A2
A3
B0
B1
B2
B3
B4
B5
B6
B7
NOTE 1: Write burst interrupt function is only allowed on burst of 8. Burst interrupt of 4 is prohibited.
NOTE 2: Write burst of 8 can only be interrupted by another Write command. Write burst interruption by Read command or
Precharge command is prohibited.
NOTE 3: Write burst interrupt must occur exactly two clocks after previous Write command. Any other Write burst interrupt
timings are prohibited.
NOTE 4: Write burst interruption is allowed to any bank inside DRAM.
NOTE 5: Write burst with Auto Precharge enabled is not allowed to interrupt.
NOTE 6: Write burst interruption is allowed by another Write with Auto Precharge command.
NOTE 7: All command timings are referenced to burst length set in the mode register. They are not referenced to actual
burst. For example, minimum Write to Precharge timing is WL + BL/2 + tWR where tWR starts with the rising clock after the
uninterrupted burst end and not from the end of actual burst end.
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EM68C08CWAE
Figure 29. Write data mask
Data Mask Timing
DQS
DQS#
DQ
DM
Data Mask Function, WL=3, AL=0, BL=4 shown
VIH(ac)VIH(dc)
VIH(ac)VIH(dc)
VIL(ac)VIL(dc)
VIL(ac)VIL(dc)
tDS tDH
tDS tDH
Case 1: min tDQSS
CK#
CK
tWR
COMMAND
DQS
DQS#
Write
WL
tDQSS
DQ
DM
Case 2: max tDQSS
tDQSS
DQS
DQS#
DQ
DM
Rev. 1.1
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EM68C08CWAE
Figure 30. Burst read operation followed by precharge:
(RL=4, AL=1, CL=3, BL=4, tRTP ≦2 clocks)
T0
CK#
T1
T2
T3
T4
T5
T6
T7
T8
CK
Post CAS#
Read A
CMD
NOP
NOP
NOP
Precharge
NOP
Bank A
Active
NOP
NOP
AL+BL'/2 clks
DQS
DQS#
AL=1
CL=3
>=tRP
RL=4
DQ
DOUTA0 DOUTA1 DOUTA2 DOUTA3
>=tRAS
>=tRTP
CL=3
Figure 31. Burst read operation followed by precharge:
(RL=4, AL=1, CL=3, BL=8, tRTP≦2 clocks)
CK#
CK
T0
CMD
DQS
DQS#
DQ's
T1
Post CAS#
READ A
T2
NOP
T3
NOP
T4
NOP
NOP
T5
T6
T7
NOP
Precharge A
T8
NOP
NOP
AL + BL/2 clks
CL = 3
AL = 1
RL= 4
DOUT
A0
DOUT
A1
DOUT
A2
DOUT
A3
DOUT
A4
DOUT
A5
DOUT
A6
DOUT
A7
>=tRTP
First 4-bit prefetch
Rev. 1.1
Second 4-bit prefetch
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EM68C08CWAE
Figure 32. Burst read operation followed by precharge:
(RL=5, AL=2, CL=3, BL=4, tRTP≦2 clocks)
T0
T1
T2
T3
T4
T5
T6
T7
T8
CK#
CK
Post CAS#
READ A
CMD
NOP
NOP
NOP
NOP
Precharge A
NOP
Bank A
Activate
NOP
AL + BL/2 clks
DQS
DQS#
CL = 3
AL = 2
>=tRP
RL= 5
DOUT
A0
DQ's
>=tRAS
DOUT
A1
DOUT
A2
DOUT
A3
CL = 3
>=tRTP
Figure 33. Burst read operation followed by precharge:
(RL=6, AL=2, CL=4, BL=4, tRTP≦2 clocks)
T0
T1
T2
T3
T4
T5
T6
T7
T8
CK#
CK
CMD
Post CAS#
READ A
NOP
NOP
NOP
Precharge A
NOP
NOP
Bank A
Activate
NOP
AL + BL/2 clks
DQS
DQS#
CL = 4
AL = 2
>=tRP
RL= 6
DOUT
A0
DQ's
>=tRAS
DOUT
A1
DOUT
A2
DOUT
A3
CL = 4
>=tRTP
Rev. 1.1
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Jul. /2014
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EM68C08CWAE
Figure 34. Burst read operation followed by precharge:
(RL=4, AL=0, CL=4, BL=8, tRTP>2 clocks)
T0
CK#
T1
T2
T3
T4
T5
T6
T7
T8
CK
Post CAS#
READ A
CMD
NOP
NOP
NOP
NOP
NOP
Precharge A
NOP
Bank A
Activate
AL + 2 + max( tRTP, 2 tCK)*
DQS
DQS#
CL = 4
AL = 0
>=tRP
RL= 4
DQ's
DOUT
A0
>=tRAS
DOUT
A1
DOUT
A2
DOUT
A3
DOUT
A4
DOUT
A5
DOUT
A6
DOUT
A7
>=tRTP
First 4-bit prefetch
Second 4-bit prefetch
*: rounded to next integer.
Figure 35. Burst write operation followed by precharge: WL= (RL-1) =3
CK#
T0
T1
T2
T3
T4
T5
T6
T7
T8
CK
CMD
Post CAS#
Write A
NOP
NOP
NOP
NOP
NOP
NOP
NOP
Precharge A
Completion of the Burst Write
DQS
DQS#
DQ's
Rev. 1.1
>=tWR
WL= 3
DNA0
DNA1
47
DNA2 DNA3
Jul. /2014
EtronTech
EM68C08CWAE
Figure 36. Burst write followed by precharge: WL= (RL-1) =4
T0
CK#
T1
T2
T3
T4
T5
T6
T7
T9
CK
Post CAS#
Write A
CMD
NOP
NOP
NOP
NOP
NOP
NOP
NOP
Precharge A
Completion of the Burst Write
>=tWR
DQS
DQS#
WL= 4
DQ's
DNA0
DNA1
DNA2 DNA3
Figure 37. Burst read operation with auto precharge:
(RL=4,AL=1, CL=3, BL=8, tRTP≦2 clocks)
T0
T1
T2
T3
T4
T5
T6
T7
T8
CK#
CK
CMD
Post CAS#
READ A
Autoprecharge
DQS
DQS#
NOP
NOP
NOP
NOP
NOP
NOP
Bank A
Activate
NOP
>= tRP
AL + BL/2 clks
CL = 3
AL = 1
RL= 4
DQ's
>=tRTP
tRTP
First 4-bit prefetch
Rev. 1.1
Second 4-bit prefetch
48
DOUT
A0
DOUT
A1
DOUT
A2
DOUT
A3
DOUT
A4
DOUT
A5
DOUT
A6
DOUT
A7
Precharge begins here
Jul. /2014
EtronTech
EM68C08CWAE
Figure 38. Burst read operation with auto precharge:
(RL=4, AL=1, CL=3, BL=4, tRTP>2 clocks)
T0
CK#
CK
T1
Post CAS#
READ A
CMD
T2
NOP
NOP
T4
NOP
NOP
T5
T6
NOP
NOP
T7
Bank A
Activate
T8
NOP
>= AL+tRTP+tRP
Autoprecharge
DQS
DQS#
T3
AL= 1
CL= 3
RL= 4
DQ's
DoutA0 DoutA1 DoutA2 DoutA3
tRTP
tRP
First 4-bit prefetch
Precharge begins here
Figure 39. Burst read operation with auto precharge followed by activation to the same
bank (tRC Limit): RL=5(AL=2, CL=3, internal tRCD=3, BL=4, tRTP≦2 clocks)
CK#
CK
T0
T1
T2
T3
T4
T5
T6
T7
T8
A10= 1
CMD
DQS
DQS#
Post CAS#
READ A
NOP
NOP
NOP
NOP
NOP
NOP
Bank A
Activate
>=tRAS(min) Auto Precharge Begins
AL= 2
CL= 3
>=tRP
RL= 5
DQ's
DoutA0 DoutA1 DoutA2 DoutA3
CL=3
>= tRC
Rev. 1.1
NOP
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EM68C08CWAE
Figure 40. Burst read operation 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≦2 clocks)
T0
CK#
CK
T1
T2
T3
T4
T5
T6
T7
T8
A10= 1
Post CAS#
READ A
CMD
NOP
NOP
NOP
>=tRAS(min)
NOP
NOP
Bank A
Activate
NOP
NOP
Auto Precharge Begins
DQS
DQS#
AL= 2
>= tRP
CL= 3
RL= 5
DQ's
DoutA0 DoutA1 DoutA2 DoutA3
CL=3
>= tRC
Figure 41. Burst write with auto-precharge (tRC Limit): WL=2, WR=2, BL=4, tRP=3
T0
CK#
CK
T1
T2
T3
T4
T5
T6
T7
Tm
A10 = 1
CMD
Post CAS#
WRA Bank A
NOP
NOP
NOP
NOP
NOP
NOP
NOP
Bank A
Active
Completion of the Burst Write
DQS
DQS#
DQ's
Rev. 1.1
Auto Precharge Begins
>=WR
WL= RL-1=2
DNA0
DNA1
>=tRP
DNA2 DNA3
>=tRC
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EM68C08CWAE
Figure 42. Burst write with auto-precharge (WR+tRP): WL=4, WR=2, BL=4, tRP=3
T0
T3
T4
T5
T6
T7
T8
T9
T12
CK#
CK
A10=1
CMD
Post CAS#
WRA Bank A
NOP
NOP
NOP
NOP
NOP
NOP
NOP
Bank A
Active
Completion of the Burst Write
Auto Precharge Begins
DQS
DQS#
>=WR
>=tRP
WL= RL-1=4
DQ's
DNA0
DNA1
DNA2 DNA3
>=tRC
Figure 43. Refresh command
T0
T1
T2
T3
Tm
Tn
Tn+1
CK#
CK
HIGH
CKE
CMD
Rev. 1.1
>=tRP
Precharge
NOP
>=tRFC
NOP
REF
>=tRFC
REF
51
NOP
ANY
Jul. /2014
EtronTech
EM68C08CWAE
Figure 44. Self refresh operation
T0
CK#
tCH
tCK
T1
T2
T3
T4
T5
T6
Tm
Tn
tCL
CK
>=tXSNR
tRP*
>=tXSRD
CKE
VIH(ac)
VIL(ac)
tAOFD
ODT
tIS
tIS
VIL(ac)
tIS
tIS tIH tIH
tIS
VIH(ac)
Self VIH(dc)
VIL(ac) Refresh VIL(dc)
CMD
tIH
NOP
NOP
NOP
Valid
NOTE 1 Device must be in the "All banks idle" state prior to entering Self Refresh mode.
NOTE 2 ODT must be turned off tAOFD before entering Self Refresh mode, and can be
turned on again when tXSRD timing is satisfied.
NOTE 3 tXSRD is applied for Read or a Read with autoprecharge command.
tXSNR is applied for any command except a Read or a Read with autoprecharge command.
Figure 45. Basic power down entry and exit timing diagram
CK
CK#
CKE
Command
tIH
VALID
tIS
tIH
NOP
tIS
NOP
NOP
tCKE min
tIS tIH
VALID
VALID
or NOP
tXP, tXARD
tXARDS
Exit Power-Down mode
Enter Power-Down mode
tIH
tCKE(min)
Don't Care
Figure 46. CKE intensive environment
CK#
CK
tCKE
tCKE
CKE
tCKE
tCKE
NOTE: DRAM guarantees all AC and DC timing & voltage specifications and proper DLL operation with intensive CKE operation
Rev. 1.1
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EM68C08CWAE
Figure 47. CKE intensive environment
CK#
CK
CKE
tCKE
tCKE
tCKE
tXP
CMD
tCKE
tXP
REF
REF
tREFI
NOTE: The pattern shown above can repeat over a long period of time. With this pattern, DRAM guarantees all AC and DC timing & voltage
specifications and DLL operation with temperature and voltage drift
Figure 48. Read to power-down entry
T0
T1
T2
Tx
Tx+1
Tx+2
Tx+3
Tx+4
Tx+5
Tx+6
Tx+7
Tx+8
Tx+9
Tx+8
Tx+9
CK#
CK
CMD
Read operation starts with a read command and
RD
CKE should be kept HIGH until the end of burst operation
BL=4
CKE
AL+CL
Q
DQ
Q
Q
tIS
Q
DQS
DQS#
T0
T1
T2
Tx
Tx+1
Tx+2
Tx+3
Tx+4
Tx+5
Tx+6
Tx+7
CK#
CK
CMD
RD
CKE should be kept HIGH until the end of burst operation
BL=8
CKE
AL+CL
DQ
Q
Q
Q
Q
Q
Q
Q
Q
tIS
DQS
DQS#
Rev. 1.1
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EM68C08CWAE
Figure 49. Read with autoprecharge to power-down entry
T0
T1
T2
Tx
Tx+1
Tx+2
Tx+3
Tx+4
Tx+5
Tx+6
Tx+7
Tx+8
Tx+9
Tx+8
Tx+9
CK#
CK
CMD
RDA
PRE
BL=4
CKE should be kept HIGH until the end of burst operation
AL+BL/2 with tRTP = 7.5ns
& tRAS min satisfied
CKE
AL+CL
Q
DQ
Q
Q
tIS
Q
DQS
DQS#
T0
T1
T2
Tx
Tx+1
Tx+2
Tx+3
Tx+4
Tx+5
Tx+6
Tx+7
CK#
CK
Start internal precharge
CMD
RD
PRE
BL=8
CKE should be kept HIGH until the end of burst operation
AL+BL/2 with tRTP = 7.5ns
& tRAS min satisfied
CKE
AL+CL
Q
DQ
Q
Q
Q
Q
Q
Q
tIS
Q
DQS
DQS#
Figure 50. Write to power-down entry
CK#
T0
T1
Tm
Tm+1
Tm+2
Tm+3
Tx
Tx+1
Tx+2
Ty
Ty+1
Ty+2
Ty+3
Tx
Tx+1
Tx+2
Tx+3
Tx+4
CK
CMD
WR
BL=4
CKE
WL
Q
DQ
Q
Q
tIS
Q
tWTR
DQS
DQS#
CK#
T0
T1
Tm
Tm+1
Tm+2
Tm+3
Tm+4
Tm+5
CK
CMD
WR
BL=8
CKE
WL
DQ
Q
Q
Q
Q
Q
Q
Q
tIS
Q
tWTR
DQS
DQS#
Rev. 1.1
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Jul. /2014
EtronTech
EM68C08CWAE
Figure 51. Write with autoprecharge to power-down entry
T0
T1
Tm
Tm+1
Tm+2
Tm+3
Tx
Tx+1
Tx+2
Tx+3
Tx+4
Tx+5
Tx+6
Tx+1
Tx+2
Tx+3
Tx+4
CK#
CK
CMD
WRA
PRE
BL=4
CKE
WL
Q
DQ
Q
Q
tIS
Q
WR*1
DQS
DQS#
T0
T1
Tm
Tm+1
Tm+2
Tm+3
Tm+4
Tm+5
Tx
CK#
CK
Start internal Precharge
CMD
WRA
PRE
BL=8
CKE
WL
DQ
Q
Q
Q
Q
Q
Q
Q
tIS
Q
WR*1
DQS
DQS#
*1: WR is programmed through MRS
Rev. 1.1
55
Jul. /2014
EtronTech
EM68C08CWAE
Figure 52. Refresh command to power-down entry
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
T10
T11
T8
T9
T10
T11
CK#
CK
CMD
REF
CKE can go to LOW one clock after an Auto-refresh command
CKE
tIS
Figure 53. Active command to power-down entry
T0
CMD
T1
T2
T3
T4
T5
T6
T7
ACT
CKE can go to LOW one clock after an Active command
CKE
tIS
Figure 54. Precharge/precharge-all command to power-down entry
T0
CMD
T1
T2
T3
T4
T5
T6
T7
T8
T9
T10
T11
PR or PRA
CKE can go to LOW one clock after a Precharge or Precharge all command
CKE
tIS
Figure 55. MRS/EMRS command to power-down entry
T0
CMD
T1
MRS or
EMRS
T2
T3
T4
T5
T6
T7
T8
T9
T10
T11
tMRD
CKE
tIS
Rev. 1.1
56
Jul. /2014
EtronTech
EM68C08CWAE
Figure 56. Asynchronous CKE LOW event
Stable clocks
tCK
CK#
CK
CKE
tDelay
CKE asynchronously drops LOW
tIS
Clocks can be turned off after this point
Figure 57. Clock frequency change in precharge power down mode
CK#
CK
T0
CMD
T1
T2
NOP
NOP
T4
Tx
Tx+1
Ty
Ty+1
Ty+2
Ty+3
NOP
NOP
Ty+4
DLL
RESET
Tz
NOP
Valid
Frequency Change Occurs here
CKE
ODT
tIS
tXP
tRP
tAOFD
Minimum 2 clocks required before
changing frequency
Rev. 1.1
200 Clocks
tIS
Stable new clock before power
down exit
57
tIH
ODT is off during DLL RESET
Jul. /2014
EtronTech
EM68C08CWAE
Figure 58. 60-Ball FBGA Package Outline Drawing Information
PIN A1 INDEX
Top View
Bottom View
Side View
DETAIL : "A"
Symbol
A
A1
D
E
D1
E1
F
e
b
D2
Rev. 1.1
Dimension in inch
Min
Nom Max
Dimension in mm
Min
Nom Max
-0.010
---
0.047
0.016
-0.25
---
1.20
0.40
0.311
0.315
0.319
7.90
8.00
8.10
0.340
0.394
0.0.398
9.90
10.00
10.10
--
0.252
--
--
6.40
--
--
0.315
--
--
8.00
--
--
0.126
--
--
3.20
--
--
0.031
--
--
0.80
--
0.016
0.018
0.020
0.40
0.45
0.50
--
--
0.081
--
--
2.05
58
Jul. /2014