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Feb.'00
MITSUBISHI LSIs
MITSUBISHI ELECTRIC
SDRAM (Rev.3.2)
64M Synchronous DRAM
M2V64S20DTP-6,-6L,-7,-7L,-8,-8L
M2V64S30DTP-6,-6L,-7,-7L,-8,-8L
M2V64S40DTP-6,-6L,-7,-7L,-8,-8L
(4-BANK x 4,194,304-WORD x 4-BIT)
(4-BANK x 2,097,152-WORD x 8-BIT)
(4-BANK x 1,048,576-WORD x 16-BIT)
5
BASIC FUNCTIONS
The M2V64S20, 30 and 40DTP provides basic functions, bank (row) activate, burst read and write, bank
(row) precharge, and auto and self refresh. Each command is defined by control signals of /RAS, /CAS and
/WE at CLK rising edge. In addition to 3 signals, /CS ,CKE and A10 are used as chip select, refresh option,
and precharge option, respectively. To know the detailed definition of commands, please see the command
truth table.
Activate (ACT) [/RAS =L, /CAS =/WE =H]
ACT command activates a row in an idle bank indicated by BA.
Read (READ) [/RAS =H, /CAS =L, /WE =H]
READ command starts burst read from the active bank indicated by BA. First output data appears after
/CAS latency. When A10 =H at this command, the bank is deactivated after the burst read (auto-
precharge,
READA
)
Write (WRITE) [/RAS =H, /CAS =/WE =L]
WRITE command starts burst write to the active bank indicated by BA. Total data length to be written
is set by burst length. When A10 =H at this command, the bank is deactivated after the burst write
(auto-precharge,
WRITEA
).
Precharge (PRE) [/RAS =L, /CAS =H, /WE =L]
PRE command deactivates the active bank indicated by BA. This command also terminates burst read
/write operation. When A10 =H at this command, all banks are deactivated (precharge all,
PREA
).
Auto-Refresh (REFA) [/RAS =/CAS =L, /WE =CKE =H]
REFA command starts auto-refresh cycle. Refresh address are generated internally. After this
command, the banks are precharged automatically.
/CS
Chip Select : L=select, H=deselect
/RAS
Command
/CAS
Command
/WE
Command
CKE
Refresh Option @refresh command
A10
Precharge Option @precharge or read/write command
CLK
define basic commands