is43r32800 Integrated Silicon Solution, Inc., is43r32800 Datasheet - Page 35

• Manufacturer Part Number: is43r32800
• Description: 256mb Ddr Synchronous Dram
• Manufacturer: Integrated Silicon Solution, Inc.

IS43R32800
Integrated Silicon Solution, Inc. — www.issi.com
Rev. A
01/14/09
I nitial ize and Mode Registersets
AUTO R EFRESH
Command
command. The refresh address is generated internally. 4096 RE FA cycles within 64ms refresh
256Mbits memory cells. The auto-refresh is performed on 4 banks concurrently. B efore performing
an auto refresh, all banks must be in the idle state. A uto-refresh to auto-refresh interval is minimum
tRFC . A ny command must not be supplied to the device before tRF C from the RE FA command.
A0-7 ,9-11
Single cycle of auto-refresh is initiated with a REF A( /CS=/R AS =/CA S=L, /WE=CK E=H)
BA 0,1
/CLK
DQS
CK E
CL K
BA 0,1
A0-1 1
A8
DQ
/RAS
/CAS
/CLK
CK E
CL K
/WE
/CS
Auto Refresh on Al l B anks
NOP
PR E
1
Ex tendedMode
Register Set
EM RS
Code
Code
1 0
tMRD
NOP or DESEL EC T
Auto-Ref resh
tRFC
In itia li ze and M RS
Mode Register Set,
MR S
Code
Code
0 0
Reset DLL
tMRD
PR E
1
Auto Refresh on All Ba nks
tRP
AR
tRFC
AR
tRFC
MR S
Code
0 0
tMRD
AC T
Xa
Xa
Xa
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