is43r32800b Integrated Silicon Solution, Inc., is43r32800b Datasheet - Page 5

• Manufacturer Part Number: is43r32800b
• Description: 8mx32 256mb Ddr Synchronous Dram
• Manufacturer: Integrated Silicon Solution, Inc.

Prechar ge (P RE ) [ /RAS =L , /CA S =H, /WE = L]
Auto-Ref resh (REFA ) [ /RAS =/CA S =L, /WE = CK E = H]
Activate ( ACT) [/RA S =L, /CAS =/WE =H ]
Read (R EAD) [/RAS =H , /CA S =L, /WE = H]
Write (WRITE)
IS43R32800B
Integrated Silicon Solution, Inc. — www.issi.com
Rev. 00D
03/19/08
/CAS latency. When A8 =H at this command, the bank is deactivated after the burst read (auto-
precharge READ A )
ISSI's 256-Mbit DDR SDRAM
precharge , and auto / self refresh. E ach command is defined by control signals of /RA S, /CAS and
/WE at CLK rising edge. I n addition to 3 signals, /CS ,C KE and A8 are usedas chip select, refresh
option, and prechargeoption, respect ively. To know the detailed definition of commands, please
see the command truth table.
internally. A fter this command, the banks are precharged automatically.
(auto-precharge, WRITEA )
/write operation. When A8 =H at this command, all banks are deactivated (precharge all, PREA ).
FUNCTIONAL DESCRIPTION
AC T c ommand activates a row in an idle bank indicated by BA .
RE AD command starts burst read from the active bank indicated by BA . F irst output data appear s after
WR IT E c ommand starts burst write to the active bank indicated by BA . T otal data length to be written
is set by burst length. W hen A8 =H at this command, the bank is deactivated after the burst write
RE FA command starts auto-refresh cycle. R efresh address including bank address are generated
PR E c ommand deactivates the active bank indicated by BA . T his command also terminates burst read
/CLK
CL K
/CS
/RAS
/CAS
/WE
CK E
A8
[/RA S =H, /CAS =/WE =L ]
provides basic functions, bank (row) activate, burst read / write, bank (row)
Chip Select : L =select, H=deselect
Command
Command
Command
Refresh Option @ refresh command
Precharge Option @ precharge or read/write command
define basic commands
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