IS43DR32800A-37CBLI ISSI, IS43DR32800A-37CBLI Datasheet - Page 29

• Manufacturer Part Number: IS43DR32800A-37CBLI
• Description: DRAM 256M (8Mx32) 266MHz Industrial Temp
• Manufacturer: ISSI

Specifications of IS43DR32800A-37CBLI

• Product Category: DRAM
• Rohs: yes
• Factory Pack Quantity: 162

IS43DR32800A, IS43/46DR32801A
Power-up and Initialization Sequence (cont'd)
f) Issue EMRS to enable DLL.
g) Issue a Mode Register Set command for DLL reset.
h) Issue a precharge all command.
i) Issue 2 or more auto-refresh commands.
j) Issue a MRS command with LOW to A8 to initialize device operation. (i.e. to program operating parameters without
resetting the DLL.)
k) At least 200 clocks after step h, execute OCD Calibration (Off Chip Driver impedance adjustment).
If OCD calibration is not used, EMRS to EMR(1) to set OCD Calibration Default (A9=A8=A7=HIGH) followed by
EMRS to EMR(1) to exit OCD Calibration Mode (A9=A8=A7=LOW) must be issued with other operating parameters of
EMR(1).
l) The DDR2 SDRAM is now ready for normal operation.
Initialization Sequence after Power-Up
Programming the Mode and Extended Mode Registers
For application flexibility, burst length, burst type, CAS latency, DLL reset function, write recovery time (WR) are user
defined variables and must be programmed with a Mode Register Set (MRS) command. Additionally, DLL disable
function, driver impedance, additive CAS latency, ODT (On Die Termination), single-ended strobe, and OCD (off chip
driver impedance adjustment) are also user defined variables and must be programmed with an Extended Mode
Register Set (EMRS) command. Contents of the Mode Register (MR) or Extended Mode Registers can be altered by
re-executing the MRS or EMRS Commands. Even if the user chooses to modify only a subset of the MR, EMR(1), or
EMR(2) variables, all variables within the addressed register must be redefined when the MRS or EMRS commands
are issued.
MRS, EMRS and Reset DLL do not affect memory array contents, which means re-initialization including those can be
executed at any time after power-up without affecting memory array contents.
Integrated Silicon Solution, Inc. — www.issi.com
Rev. 00E
09/08/2010
Command
ODT
CKE
CK
/CK
tCH
tIS
tCL
NOP
400ns
PRE
ALL
tRP
DLL
ENABLE
EMRS
tMRD
DLL
RESET
MRS
tMRD
PRE
ALL
tRP
REF
tRFC
min 200 Cycle
REF
tRFC
MRS
tMRD
EMRS
OCD
Default
Follow OCD
Flowchart
EMRS
OCD
CAL. MODE
EXIT
tOIT
tIS
ANY
CMD
29