Etron EM68916CWQA-37H 8m x 16 bit ddrii synchronous dram (sdram) Datasheet

EtronTech
EM68916CWQA
8M x 16 bit DDRII Synchronous DRAM (SDRAM)
Etron Confidential
Advanced (Rev 1.1 Apr. / 2009)
Features
Overview
• JEDEC Standard Compliant
• JEDEC Standard 1.8V I/O (SSTL_18-compatible)
• Power supplies: VDD & VDDQ = +1.8V ± 0.1V
• Operating temperatue: 0 – 85 °C
• Supports JEDEC clock jitter specification
• Fully synchronous operation
• Fast clock rate: 266/333/400MHz
• Differential Clock, CK & CK#
• Bidirectional single/differential data strobe
-DQS & DQS#
4
• 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
• CAS# Latency: 3, 4, 5, 6
• WRITE latency = READ latency - 1 tCK
• Burst length: 4 or 8
• Burst type: Sequential / Interleave
• DLL enable/disable
• Off-Chip Driver (OCD)
-Impedance Adjustment
-Adjustable data-output drive strength
On-die
termination (ODT)
•
•RoHS compliant
• Auto Refresh and Self Refresh
• 8192 refresh cycles / 64ms
•Package: 84-ball 8x12.5x1.2mm (max) FBGA
- Pb Free and Halogen Free
The EM68916C is a high-speed CMOS DoubleData-Rate-Two (DDR2), synchronous dynamic
random-access memory (SDRAM) containing 128
Mbits in a 16-bit wide data I/Os. It is internally
configured as a quad bank DRAM, 4 banks x 2Mb
addresses x 16 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,
Off-Chip Driver (OCD) impedance adjustment, 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 four 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
EM68916CWQA-25H
400MHz
800Mbps/pin
EM68916CWQA-3H
333MHz
667Mbps/pin
EM68916CWQA-37H
266MHz
533Mbps/pin
WQ: indicates FBGA package
A: indicates generation code
H: indicates Pb Free 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, Science-Based Industrial Park, Hsinchu, Taiwan 30077, R.O.C.
TEL: (886)-3-5782345
FAX: (886)-3-5778671
Etron Technology, Inc., reserves the right to make changes to its products and specifications without notice.
EtronTech
EM68916CWQA
Table 2. Speed Grade Information
Part Number
Clock Frequency
CAS Latency
tRCD (ns)
tRP (ns)
EM68916CWQA-25H
400 MHz
6
15
15
EM68916CWQA-3H
333 MHz
5
15
15
EM68916CWQA-37H
267 MHz
4
15
15
Figure 1. Ball Assignment (FBGA Top View)
1
2
3
7
8
9
A
VDD
NC
VSS
VSSQ
UDQS#
VDDQ
B
DQ14
VSSQ
UDM
UDQS.
VSSQ
DQ15
C
VDDQ
DQ9
VDDQ
VDDQ
DQ8
VDDQ
D
DQ12
VSSQ
DQ11
DQ10
VSSQ
DQ13
E
VDD
NC
VSS
VSSQ
LDQS#
VDDQ
F
DQ6
VSSQ
LDM
LDQS
VSSQ
DQ7
G
VDDQ
DQ1
VDDQ
VDDQ
DQ0
VDDQ
H
DQ4
VSSQ
DQ3
DQ2
VSSQ
DQ5
J
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
NC
K
L
NC
M
N
VSS
P
R
VDD
Etron Confidential
2
VDD
VSS
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 2. Block Diagram
CK
CK#
DLL
CLOCK
BUFFER
~
A0
A9
A11
A12
BA0
BA1
LDQS
LDQS#
UDQS
UDQS#
MODE
REGISTER
Row
Decoder
A10/AP
COLUMN
COUNTER
CONTROL
SIGNAL
GENERATOR
Row
Decoder
COMMAND
DECODER
2M x 16
CELL ARRAY
(BANK #1)
Column Decoder
Row
Decoder
CS#
RAS#
CAS#
WE#
2M x 16
CELL ARRAY
(BANK #0)
Column Decoder
2M x 16
CELL ARRAY
(BANK #2)
Column Decoder
Row
Decoder
CKE
2M x 16
CELL ARRAY
(BANK #3)
Column Decoder
ADDRESS
BUFFER
REFRESH
COUNTER
DATA
STROBE
BUFFER
DQ0
DQ
Buffer
~
DQ15
ODT LDM
UDM
Etron Confidential
3
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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.
Etron Confidential
4
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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, BA1
Input
Bank Address: BA0 and BA1 define to which bank the BankActivate, Read, Write, or
BankPrecharge command is being applied.
A0-A12
Input
Address Inputs: A0-A11 are sampled during the BankActivate command (row address
A0-A11) and Read/Write command (column address A0-A8 with A10 defining Auto
Precharge).A12 is only for register programming.
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.
LDQS,
Input /
LDQS#
Output
Bidirectional Data Strobe: Specifies timing for Input and Output data. Read Data Strobe
is edge triggered. Write Data Strobe provides a setup and hold time for data and DQM.
LDQS is for DQ0~7, UDQS is for DQ8~15. The data strobes LDOS and UDQS may be
used in single ended mode or paired with LDQS# and UDQS# to provide differential pair
signaling to the system during both reads and writes.A control bit at EMR (1)[A10] enables
or disables all complementary data strobe signals.
UDQS
UDQS#
LDM,
Input
Data Input Mask: Input data is masked when DM is sampled HIGH during a write cycle.
LDM masks DQ0-DQ7, UDM masks DQ8-DQ15.
DQ0 - DQ15
Input /
Output
Data I/O: The DQ0-DQ15 input and output data are synchronized with the positive edges
of CK and CK#. The I/Os are byte-maskable during Writes.
ODT
Input
On Die Termination: ODT enables internal termination resistance. It is applied to each
DQ, LDQS/LDQS#, UDQS/UDQS#, LDM, and UDM signal. The ODT pin is ignored if the
EMR (1) is programmed to disable ODT.
UDM
Etron Confidential
5
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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
-
Etron Confidential
No Connect: These pins should be left unconnected.
6
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Operation Mode
Table 4 shows the truth table for the operation commands.
Table 4. Truth Table (Note (1), (2))
Command
State
CKEn-1 CKEn UDM LDM BA0,1 A10 A0-9, 11-12 CS# RAS# CAS# WE#
Row address
Idle(3)
H
H
X
X
V
Single Bank Precharge
Any
H
H
X
X
V
L
All Banks Precharge
Any
H
H
X
X
X
BankActivate
L
L
H
H
X
L
L
H
L
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
(A0 – A11)
Write
Active(3)
H
H
X
X
V
L
Write with AutoPrecharge
Active(3)
H
H
X
X
V
H
Read
Active(3)
H
H
X
X
V
L
Read and Autoprecharge
Active(3)
H
H
X
X
V
H
(Extended) Mode Register Set
Idle
H
H
X
X
V
No-Operation
Any
H
X
X
X
X
X
X
L
H
H
H
Active(4)
H
X
X
X
X
X
X
L
H
H
L
Device Deselect
Any
H
X
X
X
X
X
X
H
X
X
X
Refresh
Idle
H
H
X
X
X
X
X
L
L
L
H
SelfRefresh Entry
Idle
H
L
X
X
X
X
X
L
L
L
H
SelfRefresh Exit
Idle
L
H
X
X
X
X
X
H
X
X
X
L
H
H
H
Power Down Mode Entry
Idle
H
L
X
X
X
X
X
H
X
X
X
L
H
H
H
Power Down Mode Exit
Any
L
H
X
X
X
X
X
H
X
X
X
L
H
H
H
Data Input Mask Disable
Active
H
X
L
L
X
X
X
X
X
X
X
X
X
X
X
Burst Stop
(A0 - A8)
Column
address
(A0 - A8)
OP code
Data Input Mask Enable(5)
Active
H
X
H
H
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.
Etron Confidential
7
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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, BA1 select the
bank; A0-A11 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, “HIGH” to BA1.)
6. Issue EMRS (3) command. (To issue EMRS (3) command, provide “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.)
8. Issue a Mode Register Set command for “DLL reset”.
(To issue DLL reset command, provide "HIGH" to A8 and "LOW" to BA0-1)
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.
Etron Confidential
8
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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 - A12. 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.
-
(BA0, BA1): Bank addresses to define MRS selection.
Table 5. Mode Register Bitmap
BA1 BA0 A12
0
0
A11
PD
A10
A9
WR
A8 DLL Reset
0
No
1
Yes
A12 Active power down exit time
0
Fast exit (use tXARD)
1
Slow exit (use tXARDS)
BA1 BA0 MRS Mode
0
0
MR
0
1
EMR(1)
1
0
EMR(2)
1
1
EMR(3)
A7
0
1
A8
A7
DLL
TM
A6
Mode
Normal
Test
A5
A4
A3
CAS# Latency
BT
A3
0
1
Write recovery for autoprecharge*1
A11 A10
A9
WR(cycles)
0
0
0
Reserved
0
0
1
2
0
1
0
3
0
1
1
4
1
0
0
5
1
0
1
6
1
1
0
Reserved
1
1
1
Reserved
A2
A1
A0
Burst Length
Burst Type
Sequential
Interleave
A6
0
0
0
0
1
1
1
1
A5
0
0
1
1
0
0
1
1
A2
0
0
A4
0
1
0
1
0
1
0
1
Address Field
Mode Register
A1
1
1
A0
0
1
BL
4
8
CAS# Latency
Reserved
Reserved
Reserved
3
4
5
6
Reserved
Note 1:.For DDR2-533/667/800, 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.
Etron Confidential
9
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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# and HIGH on BA0, while controlling
the states of address pins A0 ~ A12. 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.
- 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 Resistor EMR (1) Bitmap
BA1 BA0 A12 A11 A10
0
1
Qoff
0
A9
DQS#
A8
A7
A6
OCD program
Rtt
Additive Latency
A6
0
0
1
A2
0
1
0
Rtt(NOMINAL)
ODT Disable
75Ω
1
1
50Ω
BA1 BA0 MRS mode
0
0
MR
0
1
EMR(1)
1
0
EMR(2)
A10
0
1
1
1
EMR(3)
A9
0
0
0
1
1
A8
0
0
1
0
1
A7
0
1
0
0
1
DQS#
Enable
Disable
A5
A4
A3
A2
*3
Qoff
Output buffer enabled
Output buffer disabled
A0
0
1
150Ω
OCD Calibration Program
A12
0
1
A0 Address Field
Rtt D.I.C DLL Extended Mode Register
A1
OCD Calibration mode exit; maintain setting
Drive(1)
Drive(0)
Adjust mode*1
OCD Calibration default*2
A1
0
1
A5 A4 A3
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
DLL Enable
Enable
Disable
Output Driver
Impedance Control
Full strength
Reduced strength
Additive Latency
0
1
2
3
4
5
Reserved
Reserved
NOTE 1: When Adjust mode is issued, AL from previously set value must be applied.
NOTE 2: After setting to default, OCD calibration mode needs to be exited by setting A9-A7 to 000.
NOTE 3: Output disabled – DQs, DQSs, DQSs#.This feature is intended to be used during IDD characterization of read
current.
Etron Confidential
10
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
- 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 ~ A12. 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 7. Extended Mode Resistor EMR (2) Bitmap
BA1 BA0 A12 A11 A10
1
0*1
0
A7
0
1
A9
A8
A7
A6
SRF
A5
A4
0*1
A3
A2
DCC*4
A1
A0 Address Field
*3
PASR
Extended Mode Register(2)
High Temperature Self-Refresh Rate Enable
Disable
*2
Enable
BA1 BA0 MRS mode
0
0
MR
0
1
EMR(1)
1
0
EMR(2)
1
1
EMR(3)
A3
0
1
DCC Enable
Disable
Enable
*4
A2 A1 A0 Partial Array Self Refresh for 4 Banks
0
0
0 Full array
0
0
1 Half Array (BA[1:0]=00&01)
0
1
0 Quarter Array (BA[1:0]=00)
0
1
1 Not defined
1
0
0 3/4 array (BA[1:0]=01,10&11)
1
0
1 Half array (BA[1:0]=10&11)
1
1
0 Quarter array (BA[1:0]=11)
1
1
1 Not defined
NOTE 1: The rest bits in EMRS(2) are reserved for future use and all bits in EMRS(2) except A0-A2, 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: If PASR (Partial Array Self Refresh) is enabled, data located in areas of the array beyond the specified location
will be lost if self refresh is entered. Data integrity will be maintained if tREF conditions are met and no Self Refresh
command is issued.
NOTE 4: DCC (Duty Cycle Corrector) implemented, user may be given the controllability of DCC thru EMR (2) [A3] bit.
Etron Confidential
11
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
- 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 8. Extended Mode Resistor EMR (3) Bitmap
BA1 BA0 A12 A11 A10
1
1
A9
A8
A7
A6
A5
A4
A3
A2
A1
0*1
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).
Etron Confidential
12
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
z Off-chip drive (OCD) impedance adjustment
DDR2 SDRAM supports driver calibration feature and the following flow chart is an example of
sequence.Every calibration mode command should be followed by “OCD calibration mode exit” before any
other command being issued.All MR should be programmed before entering OCD impedance adjustment
and ODT (On Die Termination) should be carefully controlled depending on system environment.
Figure 4. OCD impedance adjustment sequence
Before entering OCD impedance adjustment, all MR should be programmed and
ODT should be carefully controlled depending on system environment
Start
EMRS:OCD calibration mode exit
EMRS:Drive(1)
DQ &DQS HIGH;DQS# LOW
Test
EMRS:Drive(0)
DQ &DQS LOW;DQS# HIGH
ALL OK
ALL OK
Test
EMRS:OCD calibration mode exit
EMRS:OCD calibration mode exit
EMRS:Enter Adjust Mode
EMRS:Enter Adjust Mode
BL=4 code input to all DQs
Inc, Dec, or NOP
BL=4 code input to all DQs
Inc, Dec, or NOP
EMRS:OCD calibration mode exit
EMRS:OCD calibration mode exit
EMRS:OCD calibration mode exit
End
Etron Confidential
13
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
- Extended mode register for OCD impedance adjustment
OCD impedance adjustment can be done using the following EMRS mode. In drive mode all outputs are
driven out by DDR2 SDRAM. In Drive (1) mode, all DQ, DQS signals are driven HIGH and all DQS#
signals are driven LOW. In Drive (0) mode, all DQ, DQS signals are driven LOW and all DQS# signals are
drive HIGH. In adjust mode, BL = 4 of operation code data must be used. In case of OCD calibration
default, output driver characteristics have a nominal impedance value of 18 Ohms during nominal
temperature and voltage conditions. Output driver characteristics for OCD calibration default are specified
in the following table. OCD applies only to normal full strength output drive setting defined by EMRS and if
half strength is set, OCD default driver characteristics are not applicable. When OCD calibration adjust
mode is used, OCD default output driver characteristics are not applicable. After OCD calibration is
completed or driver strength is set to default, subsequent EMRS commands not intended to adjust OCD
characteristics must specify A7~A9 as ’000’ in order to maintain the default or calibrated value.
Table 9.OCD drive mode program
A9
A8
A7
operation
0
0
0
1
1
0
0
1
0
1
0
1
0
0
1
OCD calibration mode exit
Drive(1) DQ, DQS, HIGH and DQS# LOW
Drive(0) DQ, DQS, LOW and DQS# HIGH
Adjust mode
OCD calibration default
- OCD impedance adjust
To adjust output driver impedance, controllers must issue the ADJUST EMRS command along with a 4bit
burst code to DDR2 SDRAM as in the following table. For this operation, Burst Length has to be set to BL =
4 via MRS command before activating OCD and controllers must drive this burst code to all DQs at the
same time. DT0 in the following table means all DQ bits at bit time 0, DT1 at bit time 1, and so forth. The
driver output impedance is adjusted for all DDR2 SDRAM DQs simultaneously and after OCD calibration,
all DQs of a given DDR2 SDRAM will be adjusted to the same driver strength setting.
The maximum step count for adjustment is 16 and when the limit is reached, further increment or
decrement code has no effect. The default setting maybe any step within the 16 step range. When Adjust
mode command is issued, AL from previously set value must be applied.
Table 10.OCD adjust mode program
4bit burst code inputs to all DQs
DT0
DT1
DT2
DT3
0
0
0
0
0
0
0
1
0
0
1
0
0
1
0
0
1
0
0
0
0
1
0
1
0
1
1
0
1
0
0
1
1
0
1
0
Other Combinations
Etron Confidential
Pull-up driver strength
NOP
Increase by 1 step
Decrease by 1 step
NOP
NOP
Increase by 1 step
Decrease by 1 step
Increase by 1 step
Decrease by 1 step
14
Operation
Pull-down driver strength
NOP
NOP
NOP
Increase by 1 step
Decrease by 1 step
Increase by 1 step
Increase by 1 step
Decrease by 1 step
Decrease by 1 step
Reserved
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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,
UDQS/UDQS#, LDQS/LDQS#, UDM, and LDM 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 5. Functional representation of ODT
VDDQ
VDDQ
VDDQ
SW1
SW2
SW3
Rval1
Rval2
Rval3
DRAM
Input
Buffer
Input
pin
Rval1
SW1
VSSQ
Rval2
SW2
VSSQ
Rval3
SW3
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, and DQS# pins
Table 11.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)
Ω
60
75
90
Rtt effective impedance value for EMRS(A6,A2)=1,0;150Ω Rtt2(eff)
Ω
120
150
180
Rtt effective impedance value for EMRS(A6,A2)=1,1;50Ω Rtt3(eff)
Ω
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)=
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
⎠
Etron Confidential
15
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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 and BA1 are used to select the desired bank. The row
addresses A0 through A11 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 AutoPrecharge) 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, 4, and 5 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
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.
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. A Burst Stop command is not supported on DDR2 SDRAM devices.
Etron Confidential
16
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Table 12.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 KΩresistor 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.
Etron Confidential
17
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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, BA1, and BA0 are used to define which bank to precharge when
the command is issued.
Table 13.Bank Selection for Precharge by address bits
A10
BA1
BA0
Precharged Bank(s)
LOW
LOW
LOW
LOW
HIGH
LOW
LOW
HIGH
HIGH
DON’T CARE
LOW
HIGH
LOW
HIGH
DON’T CARE
Bank 0 only
Bank 1 only
Bank 2 only
Bank 3 only
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.
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 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.
Etron Confidential
18
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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
Auto-Precharge to the next Activate command becomes AL + tRTP + tRP. For BL = 8 the time from Read with
Auto-Precharge 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.
Table 14.Precharge &Auto Precharge Clariification
Minimum Delay between “From
Unit Notes
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
tCK
Read w/AP
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
tCK
Precharge
2
Precharge All
1
Precharge
1
tCK
Precharge All
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 4 bank device) depending on the latest precharge command issued to that bank.
From Command
Etron Confidential
To Command
19
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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.
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.
Etron Confidential
20
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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.
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.
Etron Confidential
21
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Table 15. Absolute Maximum DC Ratings
Symbol
Parameter
Rating
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 16. Operating Temperature Condition
Symbol
Parameter
Rating
Unit Note
TOPR Operating temperature
0~85
1,2
°C
NOTE1: Operating temperature is the case surface temperature on center/top of the DRAM.
NOTE2: The operating temperatue range is the temperature where all DRAM specification will be supported.
Outside of this temperature range, even if it is still within the limit of stress condition, some deviation on
portion of operating specification may be required.During operation, the DRAM case temperature must
be maintained between 0-85°C under all other specification parameter.
Table 17. Recommended DC Operating Conditions (SSTL_18)
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
Etron Confidential
22
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Table 18. Input logic level (VDD = 1.8V ± 0.1V, TOPR = 0~85 °C)
Symbol
Parameter
-25/3
-37
Unit
Min.
Max.
Min.
Max.
VREF + 0.125
VDDQ + 0.3
VREF + 0.125
VDDQ + 0.3
V
VIH (dc)
DC Input logic High Voltage
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
VDDQ + Vpeak
VREF + 0.25
VDDQ + Vpeak
V
VIL (ac)
AC Input Low Voltage
VSSQ - Vpeak
VREF – 0.2
VSSQ - Vpeak
VREF – 0.25
V
VID (ac)
AC Differential Voltage
0.5
VDDQ
0.5
VDDQ
V
0.5 x
0.5 x
0.5 x
0.5 x
V
VIX (ac) AC Differential crosspoint Voltage
VDDQ+0.175
VDDQ-0.175
VDDQ+0.175
VDDQ-0.175
NOTE1: Refer to Overshoot/undershoot specifications (Table 21 and Table 22) for Vpeak value: maximum peak
amplitude allowed for overshoot and undershoot.
Table 19. AC Input test conditions (VDD = 1.8V ± 0.1V, TOPR = 0~85 °C)
Symbol
VREF
Parameter
-25/3/37
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 20. Differential AC output parameters (VDD = 1.8V ± 0.1V, TOPR = 0~85 °C)
Symbol
-25/3/37
Parameter
Min.
Max.
Unit Note
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 21. AC overshoot/undershoot specification for address and control pins
(A0-A12, BA0-BA1, CS#, RAS#, CAS#, WE#, CKE, ODT)
Parameter
-25
-3
-37
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
0.66
0.8
1.0
V-ns
Maximum undershoot area below VSS
0.66
0.8
1.0
V-ns
Etron Confidential
23
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Table 22. AC overshoot/undershoot specification for clock, data, strobe, and mask pins
(DQ, UDQS, LDQS, UDQS#, LDQS#, DM, CK, CK#)
Parameter
-25
-3
-37
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
0.23
0.23
0.28
V-ns
Maximum undershoot area below VSS
0.23
0.23
0.28
V-ns
Table 23. Output AC test conditions (VDD = 1.8V ± 0.1V, TOPR = 0~85 °C)
Symbol
VOTR
Parameter
Output timing measurement reference level
-25/3/37
Unit
Note
0.5xVDDQ
V
1
-25/3/37
Unit
Note
-13.4
mA
1, 3, 4
NOTE1: The VDDQ of the device under test is referenced.
Table 24. Output DC current drive (VDD = 1.8V ± 0.1V, TOPR = 0~85 °C)
Symbol
Parameter
IOH(dc) Output minimum source DC current
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 25. Capacitance (VDD = 1.8V, f = 1MHz, TOPR = 25 °C)
Symbol
CIN1
CIN2
CI/O
DCIO
DCI1
DCI2
-25
Parameter
Min.
Input Capacitance : Command and Address
1.0
Input Capacitance (CK, CK#)
1.0
DM0, DM1, DQ, DQS Input/Output Capacitance
2.5
Delta Input/Output Capacitance: DM0, DM1, DQ, DQS
Delta Input Capacitance: Command and Address
Delta Input Capacitance: CK, CK#
-
Max.
1.75
2.0
3.5
0.5
0.25
0.25
-3
Min.
1.0
1.0
2.5
-
-37
Max.
2.0
2.0
3.5
0.5
0.25
0.25
Min.
1.0
1.0
2.5
-
Max.
2.0
2.0
4.0
0.5
0.25
0.25
Unit
pF
pF
pF
pF
pF
pF
NOTE: These parameters are periodically sampled and are not 100% tested.
Etron Confidential
24
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Table 26. IDD specification parameters and test conditions (VDD = 1.8V ± 0.1V, TOPR = 0~85 °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
MRS(A12)=1
bus 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
Etron Confidential
-25
-3
Max.
-37
IDD0
90
90
85
mA
IDD1
115
100
100
mA
IDD2P
10
10
10
mA
IDD2Q
40
40
35
mA
IDD2N
45
45
35
mA
35
30
30
mA
15
12
12
mA
IDD3N
64
55
50
mA
IDD4W
200
180
170
mA
IDD4R
175
160
150
mA
IDD5B
180
170
170
mA
IDD6
5
5
5
mA
IDD7
265
240
235
mA
Symbol
25
Unit
IDD3P
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Table 27. Electrical Characteristics and Recommended A.C. Operating Conditions
(VDD = 1.8V ± 0.1V, TOPR = 0~85 °C)
-25
Symbol
tCK
Parameter
Clock cycle time
Min.
-3
Max.
Min.
-37
Max.
Min.
Max.
CL=3
-
-
-
-
5
8
CL=4
3.75
8
3.75
8
3.75
8
CL=5
3
8
3
8
-
-
CL=6
2.5
8
-
-
-
-
0.52
0.48
0.52
0.45
0.55
0.52
0.48
0.52
0.45
tCH(avg)
tCL(avg)
WL
Average clock HIGH pulse width
0.48
Average Clock LOW pulse width
0.48
tDQSS
DQS latching rising transitions to associated clock
edges
tDSS
tDSH
Write command to DQS associated clock edge
RL-1
RL-1
0.55
RL-1
Unit
Specific
Notes
ns
ns
ns
ns
tCK
tCK
tCK
13, 31, 32
13, 31, 32
13, 31, 32
13, 31, 32
32, 33
32, 33
-0.25
0.25
-0.25
0.25
-0.25
0.25
tCK
26
DQS falling edge to CK setup time
0.2
-
0.2
-
0.2
-
26
DQS falling edge hold time from CK
0.2
-
0.2
-
0.2
-
tCK
tCK
tDQSH
DQS input HIGH pulse width
0.35
-
0.35
-
0.35
-
tCK
tDQSL
tWPRE
tWPST
DQS input LOW pulse width
0.35
-
0.35
-
0.35
-
Write preamble
0.35
-
0.35
-
0.35
-
Write postamble
0.4
0.6
0.4
0.6
0.4
0.6
tCK
tCK
tCK
8
tIS(base)
Address and Control input setup time
0.175
-
0.2
-
0.25
-
ns
5, 7, 20,
25
tIH(base)
Address and Control input hold time
0.25
-
0.275
-
0.375
-
ns
5, 7, 21,
25
tIPW
Control & Address input pulse width for each input
0.6
-
0.6
-
0.6
-
tCK
tDS(base)
DQ & DM input setup time (differential strobe)
0.05
-
0.1
-
0.1
-
ns
6, 7, 18,
24, 27
tDH(base)
DQ & DM input hold time (differential strobe)
0.125
-
0.175
-
0.225
-
ns
6, 7,
19,24, 27
16, 36
tDIPW
tAC
tDQSCK
tHZ
tLZ(DQS)
tLZ(DQ)
tDQSQ
tHP
tQHS
tQH
tRPRE
tRPST
tRRD
tCCD
tWR
tDAL
tWTR
tRTP
tCKE
tXSNR
tXSRD
tXP
0.24
-
0.3
tCK
ns
ns
ns
ns
ns
ns
-
min(tCL,tC
H)
-
Min
(tCL,tCH)
-
ns
9, 10, 33
0.3
-
0.34
-
0.4
10, 34
tHP -tQHS
-
tHP -tQHS
-
tHP -tQHS
-
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
-
CAS# to CAS# command delay
2
-
2
-
2
-
Write recovery time
15
-
15
-
15
-
WR + tRP
-
WR + tRP
-
WR + tRP
-
Internal Write to Read Command Delay
7.5
-
7.5
-
7.5
-
Internal read to precharge command delay
7.5
-
7.5
-
7.5
-
3
-
3
-
3
-
tRFC+10
-
tRFC+10
-
tRFC+10
-
200
-
200
-
200
-
2
-
2
-
2
-
ns
ns
tCK
tCK
ns
tCK
ns
ns
ns
ns
tCK
ns
tCK
tCK
DQ and DM input pulse width for each input
0.35
-
0.35
-
0.35
-
DQ output access time from CK, CK#
-0.4
0.4
-0.45
0.45
-0.5
0.5
DQS output access time from CK, CK#
-0.35
0.35
-0.4
0.4
-0.45
0.45
Data-out high-impedance time from CK, CK#
DQS(DQS#) low-impedance time from CK, CK#
DQ low-impedance time from CK, CK#
DQS-DQ skew for DQS and associated DQ signals
-
tAC(min)
2tAC(min)
0.2
-
CK half pulse width
min(tCL,tC
H)
DQ hold skew factor
-
DQ/DQS output hold time from DQS
Read preamble
Auto Power write recovery + precharge time
CKE minimum pulse width
Exit self refresh to non-read command delay
Exit self refresh to a read command
Exit precharge power down to any command
Etron Confidential
-
tAC(max)
tAC(max)
tAC(max)
tAC(max) tAC(min) tAC(max) tAC(min) tAC(max)
tAC(max) 2tAC(min) tAC(max) 2tAC(min) tAC(max)
-
26
-
Rev. 1.1
36
36
16, 36
16, 36
11
35
17, 37
17, 38
4, 28
28
12, 29
3, 22, 28
3, 28
23
28
Apr. 2009
EtronTech
tXARD
Exit active power down to read command
tXARDS
Exit active power down to read command(slow
exit, lower power)
tAOND
ODT turn-on delay
tAON
ODT turn-on
tAONPD
ODT turn-on (Power-Down mode)
tAOFD
ODT turn-off delay
tAOF
ODT turn-off
tAOFPD
ODT turn-off (Power-Down mode)
tANPD
tAXPD
tMRD
tMOD
tOIT
tDelay
tRFC
tREFI
tRCD
tRP
tRC
tRAS
EM68916CWQA
2
-
2
-
2
-
tCK
1
8-AL
-
7-AL
-
6-AL
-
tCK
1, 2
2
2
2
2
2
2
tAC(min)
tAC(max)
+0.7
tAC(min)
tAC(max)
+0.7
tCK
14
t (max)+
tAC(min) AC
1
ns
6, 14, 36
2 tCK
2 tCK
2 tCK
tAC(min)+
t (min)+
t (min)+
+tAC(max AC
+tAC(max AC
+tAC(max)
2
2
2
)+1
)+1
+1
ns
2.5
tAC(min)
2.5
2.5
2.5
2.5
2.5
tCK
tAC(max)+ tAC(min) tAC(max)+ tAC(min) tAC(max)+ ns
0.6
0.6
0.6
2.5 tCK
2.5 tCK
2.5 tCK
tAC(min)+
t (min)+
t (min)+
+tAC(max AC
+tAC(max AC
+tAC(max)
2
2
2
)+1
)+1
+1
ODT to power down entry latency
3
-
3
-
3
-
8
-
8
-
8
-
Mode register set command cycle time
2
-
2
-
2
-
MRS command to ODT update delay
0
12
0
12
0
12
0
12
0
12
0
12
tCK
tCK
tCK
ns
ns
-
tIS+ tCK
+tIH
-
tIS+ tCK
+tIH
-
ns
75
-
75
-
75
-
ns
-
7.8
-
7.8
-
7.8
15
-
15
-
15
-
µs
ns
ns
ns
ns
Minimum time clocks remains ON after CKE
asynchronously drops LOW
Refresh to active/Refresh command time
Average periodic refesh interval
RAS# to CAS# Delay time
tIS+ tCK
+tIH
Row precharge Delay time
15
-
15
-
15
-
Row cycle Delay time
60
-
60
-
60
-
Row active Delay time
45
70k
45
70k
45
70k
Etron Confidential
27
Rev. 1.1
15, 39, 41
ns
ODT power down exit latency
OCD drive mode output delay
15, 40, 41
28
28
13
Apr. 2009
EtronTech
EM68916CWQA
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 6. AC timing reference load
VDDQ
DQ
DUT DQS
Ouput
25Ω
DQS#
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
between DQS 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 7. Slew rate test load
VDDQ
DQ
DUT DQS
Ouput
25Ω
DQS#
VTT=VDDQ/2
Test point
Etron Confidential
28
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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 (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: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 9: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 10: 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 pchannel to n-channel variation of the output drivers.
NOTE 11: 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 12: 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 13: 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.
Etron Confidential
29
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
NOTE 14: 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 DDR2-533, tAOND is 10 ns (= 2 x 5 ns) after the clock edge that
registered a first ODT HIGH if tCK = 5 ns. For DDR2-667/800, tAOND is 2 clock cycles after the clock edge
that registered a first ODT HIGH counting the actual input clock edges.
NOTE 15: 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 DDR2-533, tAOFD is 12.5 ns (= 2.5 x 5 ns) after the clock edge that registered a first ODT
LOW if tCK = 5 ns. For DDR2-667/800, if tCK(avg) = 3 ns is assumed, tAOFD is 1.5 ns (= 0.5 x 3 ns) after the
second trailing clock edge counting from the clock edge that registered a first ODT LOW and by counting
the actual input clock edges.
NOTE 16: 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 17: 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 18: 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 19: 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 20: 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 21: 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 22: tWTR is at lease two clocks (2 x tCK ) independent of operation frequency.
NOTE 23: 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 24: 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 25: 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 26: These parameters are measured from a data strobe signal (LDQS/UDQS) 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 27: These parameters are measured from a data signal ((L/U) DM, (L/U) DQ0, (L/U) DQ1, etc.)
transition edge to its respective data strobe signal (LDQS/UDQS/LDQS#/UDQS#) crossing.
NOTE 28: 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.
Etron Confidential
30
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
NOTE 29: 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 30: New units, ‘tCK(avg)’ is introduced in DDR2-667 and DDR2-800. Unit ‘tCK (avg)’ represents the
actual tCK(avg) of the input clock under operation.
NOTE 31: 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 and DDR2-800 only. The
jitter specified is a random jitter meeting a Gaussian distribution.
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
-25
-3
tJIT (per)
Min
-125
Max
125
Min
-100
Max
100
tJIT (per,lck)
-100
100
-80
tJIT (cc)
-250
250
tJIT (cc,lck)
-200
Cumulative error across 2 cycles
tERR (2per)
Cumulative error across 3 cycles
Units Note
ps
33
80
ps
33
-200
200
ps
33
200
-160
160
ps
33
-175
175
-150
150
ps
33
tERR (3per)
-225
225
-175
175
ps
33
Cumulative error across 4 cycles
tERR (4per)
-250
250
-200
200
ps
33
Cumulative error across 5 cycles
Cumulative error across n cycles,
n=6...10, inclusive
tERR (5per)
-250
250
-200
200
ps
33
tERR (6-10per)
-350
350
-300
300
ps
33
Cumulative error across n cycles,
n=11...50, inclusive
tERR (11-50per)
-450
450
-450
450
ps
33
Duty cycle jitter
tJIT (duty)
-125
125
-100
100
ps
33
Definitions:
- tCK(avg)
tCK(avg) is calculated as the average clock period across any consecutive 200 cycle window.
⎡
⎤
N
t CK ( avg ) = ⎢∑ t CK ⎥ / N
⎣ j =1
j
⎦
where N=200
- tCH(avg) and tCL(avg)
tCH(avg) is defined as the average HIGH pulse width, as calculated across any consecutive 200 HIGH
pulses.
⎡
⎤
t CH ( avg ) = ⎢∑ t CH ⎥ / ( N × t CK ( avg ) )
N
⎣ j =1
j
⎦
where N=200
tCL(avg) is defined as the average LOW pulse width, as calculated across any consecutive 200 LOW pulses.
⎡N
⎤
avg
/ N × t CK ( avg )
=
t CL ( ) ⎢⎣∑
t
CL j ⎥
j =1
⎦
(
)
where N=200
tJIT (duty) is defined as the cumulative set of tCH jitter and tCL jitter. tCH jitter is the largest deviation of
any single tCH from tCH(avg). tCL jitter is the largest deviation of any single tCL from tCL(avg).
- tJIT(duty) = Min/max of {tJIT(CH), tJIT(CL)}
where,
Etron Confidential
31
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
tJIT(CH) = {tCHi- tCH(avg) where i=1 to 200}
tJIT(CL) = {tCLi- tCL(avg) where i=1 to 200}
- tJIT(per), tJIT(per,lck)
tJIT(per) is defined as the largest deviation of any single tCK from tCK(avg).
tJIT(per) = Min/max of {tCKi- tCK(avg) where i=1 to 200}
tJIT(per) defines the single period jitter when the DLL is already locked.
tJIT(per,lck) uses the same definition for single period jitter, during the DLL locking period only.
tJIT(per) and tJIT(per,lck) are not guaranteed through final production testing.
- tJIT(cc), tJIT(cc,lck)
tJIT(cc) is defined as the difference in clock period between two consecutive clock cycles:
tJIT(cc) = Max of |tCKi+1 – tCKi|
tJIT(cc) defines the cycle to cycle jitter when the DLL is already locked.
tJIT(cc,lck) uses the same definition for cycle to cycle jitter, during the DLL locking period only.
tJIT(cc) and tJIT(cc,lck) are not guaranteed through final production testing.
- tERR(2per), tERR (3per), tERR (4per), tERR (5per), tERR (6-10per) and tERR (11-50per)
tERR is defined as the cumulative error across multiple consecutive cycles from tCK(avg).
⎡ i +N −1
⎤
nper
=
(
)
⎢
∑
t ERR
t CK j ⎥⎦ − N × t CK ( avg )
⎣ j =1
(
)
⎧n=2
⎪
⎪n=3
⎪
⎪n=4
where ⎨
⎪n=5
⎪
⎪6 ≤ n ≤ 10
⎪11 ≤ n ≤ 50
⎩
for
for
for
for
for
for
( 2per )
( 3 per )
ERR
( 4 per )
ERR
( 5 per )
ERR
( 6 − 10 per )
ERR
(11 − 50 per )
ERR
t
t
t
t
t
t
ERR
NOTE 32: 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.)
Parameter
Absolute clock period
Symbol
tCK (abs)
Absolute clock HIGH pulse width tCH (abs)
Absolute clock LOW pulse width
tCL (abs)
Min
tCK(avg),min + tJIT(per),min
Max
tCK(avg),max + tJIT(per),max
Unit
ps
tCH(avg),min * tCK(avg),min +
tJIT(duty),min
tCL(avg),min * tCK(avg),min +
tJIT(duty),min
tCH(avg),max * tCK(avg),max +
tJIT(duty),max
tCL(avg), max * tCK(avg),max +
tJIT(duty), max
ps
ps
NOTE 33: 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 34: tQHS accounts for:
1) The pulse duration distortion of on-chip clock circuits, which represents how well the actual tHP at the
input is transferred to the output; and
2) The worst case push-out of DQS on one transition followed by the worst case pull-in of DQ on the next
transition, both of which are independent of each other, due to data pin skew, output pattern effects,
and p-channel to n-channel variation of the output drivers
Etron Confidential
32
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
NOTE 35: 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 36: 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 37: 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 38: 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 39: 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 40: For tAOFD of DDR2-533, the 1/2 clock of tCK in the 2.5 x tCK assumes a tCH, input clock HIGH pulse
width of 0.5 relative to tCK. tAOF,min and tAOF,max should each be derated by the same amount as the
actual amount of tCH offset present at the DRAM input with respect to 0.5.
NOTE 41: For tAOFD of DDR2-667/800, 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.
Etron Confidential
33
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Timing Waveforms
Figure 8. Initialization sequence after power-up
tCH tCL
CK
CK#
tIS
CKE
tIS
ODT
Command
EMR
S
PRE
ALL
NOP
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 9. OCD drive mode
OCD calibration mode exit
Enter Drive mode
CMD
EMRS
NOP
NOP
NOP
EMRS
CK#
CK
DQS
DQS#
Hi-Z
DQS HIGH & DQS# LOW for Drive(1), DQS LOW & DQS# HIGH for Drive(0)
Hi-Z
DQs HIGH for Drive(1)
DQ
DQs LOW for Drive(0)
tOIT
tOIT
NOTE : Drive mode, both Drive(1) and Drive(0), is used for controllers to measure DDR2 SDRAM Driver
impedance.In this mode, all outputs are driven out tOIT after "enter drive mode" command and all output
drivers are turned-off tOIT after "OCD calibration mode exit" command.
Etron Confidential
34
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 10. OCD adjust mode
OCD calibration mode exit
OCD adjust mode
CMD
EMRS
NOP
NOP
NOP
NOP
EMRS
NOP
NOP
CK#
CK
WL
DQS_in
tDS tDH
VIH(ac)
DQ_in
WR
DQS#
VIH(dc)
DT0
DT1
DT2
DT3
VIL(ac)
VIL(dc)
DM
NOTE 1: For proper operation of adjust mode, WL = RL - 1 = AL + CL - 1tCK and tDS /tDH should be met as shown in the figure.
NOTE 2: For input data pattern for adjustment, DT0-DT3 is a fixed order and is not affected by burst type
(i.e., sequential or interleave)
Figure 11. ODT update delay timing-tMOD
CMD
EMRS
NOP
NOP
NOP
NOP
NOP
CK#
CK
ODT
tIS
tAOFD
Rtt
Old setting
tMOD, min
tMOD, max
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.
Etron Confidential
35
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 12. ODT update delay timing-tMOD, as measured from outside
CK#
CK
CMD
EMRS
NOP
NOP
NOP
ODT
NOP
tIS
tAOFD
Rtt
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.
Figure 13. ODT timing for active standby mode
T0
T1
T3
T2
T4
T5
T6
CK#
CK
tIS
CKE
tIS
tIS
VIH(ac)
ODT
Internal
Term Res.
VIL(ac)
tAOND
tAOFD
RTT
tAON,min
tAON,max
Etron Confidential
36
tAOF,min
tAOF,max
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 14. 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.
RTT
tAONPD,min
tAONPD,max
Figure 15. 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.
Etron Confidential
Active & Standby mode
timings to be applied.
37
Power Down mode
timings to be applied.
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 16.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
Active & Standby mode
timings to be applied.
VIL(ac)
tAOFD
Internal
Term Res.
RTT
tIS
ODT
Power Down mode
timings to be applied.
VIL(ac)
tAOFPD max
Internal
Term Res.
RTT
tIS
Active & Standby mode
timings to be applied.
VIH(ac)
ODT
tAOND
RTT
Internal
Term Res.
VIH(ac)
Power Down mode
timings to be applied.
tIS
ODT
tAONPD max
Internal
Term Res.
RTT
Figure 17. 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
ADDRESS
Internal RAS# - CAS# delay (>=tRCD min)
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)
Etron Confidential
38
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 18.1. 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
Din 0
Dout 0 Dout 1 Dout 2 Dout 3
Din 1
Din 2
Din 3
[ AL=2 and CL=3, RL= (AL+CL)=5, WL= (RL-1)=4, BL=4]
Figure 18.2. 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]
Etron Confidential
39
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 19. Data output (read) timing
tCH
CK#
CK
tCL
CK
DQS#
DQS
DQS#
DQS
tRPRE
DQ
tRPST
tDQSQ max
Q
Q
Q
Q
tDQSQ max
tQH
tQH
Figure 20.1. Burst read operation: RL=5 (AL=2, CL=3, BL=4)
CK#
CK
CMD
T0
T1
Posted CAS#
READ A
T2
NOP
T3
NOP
NOP
T4
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 20.2. Burst read operation: RL=3 (AL=0 and CL=3, BL=8)
CK#
CK
CMD
T0
READ A
DQS
DQS#
T1
NOP
T2
NOP
T3
T4
NOP
T5
NOP
T6
NOP
T7
NOP
NOP
T8
NOP
=< tDQSCK
CL=3
RL=3
DQs
Etron Confidential
Dout A0
Dout A1
40
Dout A2
Dout A3
Dout A4
Dout A5
Dout A6
Rev. 1.1
Dout A7
Apr. 2009
EtronTech
EM68916CWQA
Figure 21. Burst read followed by burst write: RL=5, WL= (RL-1) =4, BL=4
T0
CK#
CK
CMD
T1
Post CAS#
READ A
Tn-1
NOP
Tn
Tn+1
Post CAS#
WRITE A
NOP
Tn+2
NOP
Tn+3
NOP
Tn+4
NOP
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.
Figure 22. Seamless burst read operation: RL=5, AL=2, CL=3, BL=4
T0
CK#
CK
CMD
T1
Post CAS#
READ A
NOP
T2
T3
Post CAS#
READ B
T4
NOP
NOP
T5
T6
NOP
T7
NOP
T8
NOP
NOP
DQS
DQS#
AL=2
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.
Etron Confidential
41
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 23. Read burst interrupt timing: (CL=3, AL=0, RL=3, BL=8)
CK#
CK
CMD
Read A
NOP
NOP
Read B
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).
Figure 24. Data input (write) timing
tDQSH
DQS#
tDQSL
DQS
DQS#
DQS
tWPRE
DQ
tWPSL
VIH(ac)
D
VIL(ac)
tDS
DM
Etron Confidential
VIH(dc)
D
D
VIL(dc)
tDH
tDS
tDH
VIH(dc)
VIH(ac)
DMin
D
DMin
DMin
VIL(ac)
42
DMin
VIL(dc)
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 25.1. Burst write operation: RL=5 (AL=2, CL=3), WL=4, BL=4
T0
CK#
CK
T1
Posted CAS#
WRITE A
CMD
T2
NOP
T3
NOP
T4
NOP
Case 1: with tDQSS (max)
DQS
DQS#
T5
T6
NOP
NOP
tDQSS
tDSS tDQSS
T7
NOP
tDSS
Precharge
Completion of the
Burst Write
WL = RL-1 =4
>=tWR
DQs
DNA0
Case 2: with tDQSS (min)
DQS
DQS#
NOP
Tn
tDQSS tDSH
DNA1
DNA2 DNA3
tDQSS tDSH
>=tWR
WL = RL-1 =4
DQs
DNA0
DNA1
DNA2 DNA3
Figure 25.2. Burst write operation: RL=3 (AL=0, CL=3), WL=2, BL=4
CK#
CK
CMD
T0
T1
WRITE A
NOP
T2
T3
NOP
NOP
<=tDQSS
DQS
DQS#
Etron Confidential
T5
NOP
NOP
>=tWR
DNA0
DNA1
Tm
Tm+1
NOP
Precharge
Tn
Bank A
Activate
Completion of the
Burst Write
WL = RL-1 =2
DQs
T4
>=tRP
DNA2 DNA3
43
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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.
Etron Confidential
44
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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.
Etron Confidential
45
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
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
Write
DQS
DQS#
WL
tDQSS
DQ
DM
Case 2: max tDQSS
tDQSS
DQS
DQS#
DQ
DM
Etron Confidential
46
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 30.1. 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 30.2.Burst read operation followed by precharge:
(RL=4, AL=1, CL=3, BL=8, tRTP≦2 clocks)
CK#
CK
CMD
DQS
DQS#
T0
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
DQ's
DOUT
A0
DOUT
A1
DOUT
A2
DOUT
A3
DOUT
A4
DOUT
A5
DOUT
A6
DOUT
A8
>=tRTP
First 4-bit prefetch
Etron Confidential
Second 4-bit prefetch
47
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 30.3. 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
CMD
Post CAS#
READ A
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 30.4. 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
Etron Confidential
48
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 30.5. 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
A8
>=tRTP
First 4-bit prefetch
Second 4-bit prefetch
*: rounded to next integer.
Figure 31.1. 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#
>=tWR
WL= 3
DQ's
Etron Confidential
DNA0
DNA1
49
DNA2 DNA3
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 31.2. 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 32.1. Burst read operation with auto precharge:
(RL=4,AL=1, CL=3, BL=8, tRTP≦2 clocks)
T0
CK#
CK
T1
Post CAS#
READ A
CMD
T2
NOP
NOP
Autoprecharge
DQS
DQS#
T3
T4
NOP
T5
NOP
T6
NOP
NOP
T8
Bank A
Activate
NOP
>= tRP
AL + BL/2 clks
AL = 1
T7
CL = 3
RL= 4
DQ's
>=tRTP
DOUT
A0
DOUT
A1
DOUT
A2
DOUT
A3
DOUT
A4
DOUT
A5
DOUT
A6
DOUT
A8
tRTP
First 4-bit prefetch
Etron Confidential
Second 4-bit prefetch
50
Precharge begins here
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 32.2. 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
T8
Bank A
Activate
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 32.3. 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
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
Etron Confidential
51
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 32.4. 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
CMD
Post CAS#
READ A
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 33.1. Burst write with auto-precharge (tRC Limit): WL=2, WR=2, BL=4, tRP=3
CK#
CK
T0
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#
Auto Precharge Begins
>=WR
WL= RL-1=2
DQ's
Etron Confidential
DNA0
DNA1
>=tRP
DNA2 DNA3
>=tRC
52
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 33.2. Burst write with auto-precharge (WR+tRP): WL=4, WR=2, BL=4, tRP=3
T0
CK#
T3
T4
T5
T6
T7
T8
T9
T12
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 34. Refresh command
T0
T1
T2
T3
Tm
Tn
Tn+1
CK#
CK
HIGH
CKE
CMD
>=tRP
Precharge
Etron Confidential
NOP
>=tRFC
NOP
REF
>=tRFC
REF
53
NOP
Rev. 1.1
ANY
Apr. 2009
EtronTech
EM68916CWQA
Figure 35. 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 36. Basic power down entry and exit timing diagram
CK
CK#
tIH
CKE
Command
tIS
VALID
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 37.1.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
Etron Confidential
54
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 37.2.CKE intensive environment
CK#
CK
CKE
tCKE
tCKE
tCKE
tXP
CMD
tCKE
tXP
REF
REF
tREFI = 7.8 µs
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 38. 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#
Etron Confidential
55
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 39. 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 40. 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#
Etron Confidential
56
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 41. 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
Q
DQ
Q
Q
Q
Q
Q
Q
tIS
Q
WR*1
DQS
DQS#
*1: WR is programmed through MRS
Figure 42. Refresh command to power-down entry
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
T10
T11
CK#
CK
CMD
REF
CKE can go to LOW one clock after an Auto-refresh command
CKE
tIS
Figure 43. Active command to power-down entry
T0
CMD
T1
T2
T3
T4
T5
T6
T7
T8
T9
T10
T11
ACT
CKE can go to LOW one clock after an Active command
CKE
tIS
Etron Confidential
57
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 44. 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 45. MRS/EMRS command to power-down entry
T0
T1
T2
MRS or
EMRS
CMD
T3
T4
T5
T6
T7
T8
T9
T10
T11
tMRD
CKE
tIS
Figure 46. 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 47. 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
Etron Confidential
200 Clocks
tIS
tIH
ODT is off during DLL RESET
Stable new clock before power
down exit
58
Rev. 1.1
Apr. 2009
EtronTech
EM68916CWQA
Figure 48. 84-Ball FBGA Package Outline Drawing Information
PIN A1 INDEX
Top View
Bottom View
Side View
DETAIL : "A"
Symbol
A
A1
A2
A3
D
E
D1
E1
F
e
b
D2
Etron Confidential
Dimension in inch
Dimension in mm
Min
Nom Max
Min
Nom Max
--0.047
--1.20
0.010 0.012 0.014 0.25 0.30 0.35
0.030 0.031 0.033 0.75 0.80 0.85
0.005 0.006 0.007 0.125 0.155 0.185
0.311 0.315 0.319 7.9
8.0
8.1
0.488 0.492 0.496 12.4 12.5 12.6
-0.252
--6.40
--0.441
--11.2
--0.126
--3.2
--0.031
--0.80
-0.016 0.018 0.020 0.40 0.45 0.50
--0.081
--2.05
59
Rev. 1.1
Apr. 2009