M2S56D20ATP Datasheet, PDF (27/41 Pages) Elpida Memory – 256M Double Data Rate Synchronous DRAM

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
READ
After tRCD from the bank activation, a READ command can be issued. 1st Output data is available after the
/CAS Latency from the READ, followed by (BL-1) consecutive data. (BL : Burst Length) The start address is
specified by A11,A9-A0(x4)/A9-A0(x8)/A8-A0(x16), and the address sequence of burst data is defined by the
Burst Type. A READ command may be issued to any active bank, so the row precharge time (tRP) can be
hidden during the continuous burst data by interleaving the multiple banks. When A10 is high in READ
command, the auto-precharge (READA) is performed. Any command (READ,WRITE,PRE,ACT) asserted to
the same bank is inhibited till the internal precharge is completed. The internal precharge operation starts at
BL/2 time after READA command. The next ACT command can be issued after (BL/2+tRP) time from the
previous READA.
/CLK
CLK
Command
A0-9,11
A10
BA0,1
DQS
DQ
Multi Bank Interleaving READ (BL=8, CL=2)
ACT
Xa
READ ACT
tRCD
Y Xb
Xa
0 Xb
00
00 10
READ PRE
Y
0
0
10 00
Qa0 Qa1 Qa2 Qa3 Qa4 Qa5 Qa6 Qa7 Qb0 Qb1 Qb2 Qb3 Qb4 Qb5 Qb7 Qb8
/CAS latency
Burst Length
27