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M2V56S20TP

256M Synchronous DRAM

Mitsumi 

SDRAM (Rev.1.1)

Single Data Rate

Feb.2000

MITSUBISHI LSIs

M2V56S20/ 30/ 40/ TP -6, -7, -8

256M Synchronous DRAM

BASIC FUNCTIONS

The M2V56S20/30/40TP provides basic functions, bank (row) activate, burst read / write, bank (row)

precharge, and auto / 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.

CLK

/CS

/RAS

/CAS

/WE

CKE

A10

Chip Select : L=select, H=deselect

Command

Command define basic commands

Command

Refresh Option @refresh command

Precharge Option @precharge or read/write command

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.

MITSUBISHI ELECTRIC

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