M2S56D20AKT データシートの表示（PDF） - Elpida Memory, Inc
部品番号
コンポーネント説明
メーカー
M2S56D20AKT Datasheet PDF : 41 Pages
| |||
DDR SDRAM
E0338M10 (Ver.1.0)
(Previous Rev.1.54E)
Jan. '03 CP(K)
M2S56D20/ 30/ 40ATP
M2S56D20/ 30/ 40AKT
256M Double Data Rate Synchronous DRAM
BASIC FUNCTIONS
The M2S56D20/30/40A 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. Refer to the command truth table for the detailed definition of commands.
/CLK
CLK
/CS
/RAS
/CAS
/WE
CKE
A10
Chip Select : L=select, H=deselect
Command
Command
Command
define basic commands
Refresh Option @refresh command
Precharge Option @precharge or read/write command
Activate (ACT) [/RAS =L, /CAS =/WE =H]
ACT command activates one 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 in 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 defined by burst length. When A10 =H in 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 in 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 addresses including bank address are generated
internally. After this command, the banks are precharged automatically.
7
Share Link: 