EM639165TS-75 データシートの表示（PDF） - Etron Technology

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EM639165TS-75

8Mega x 16bits SDRAM

Etron Technology 

EM639165

BASIC FUNCTIONS

The EM639165 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 opt ion, 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 command

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 deac-

tivated 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 including bank address

are generated internally. After this command, the banks are precharged automatically.

Preliminary

4

Rev 1.0 Feb. 2001

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