AS4LC4M16S0
AS4LC16M4S0
®
Mode register set command waveform
CLK
CMD
ACT
PRE
MRS
t
t
(min)
RP
RSC
MRS can be issued only when both banks are idle.
Precharge waveforms
Precharge can be asserted after tRAS (min). The selected bank will enter the idle state after tRP.. The earliest assertion of the
precharge command without losing any burst data is show below.
(normal write; BL = 4)
CLK
CMD
WE
PRE
DQ
D
0
D
1
D
D
3
2
(normal read; BL = 4)
CLK
CMD
Read data
PRE
DQ(CL2)
DQ(CL3)
Q
Q
Q
Q
3
0
1
2
Q
Q
Q
Q
3
0
1
2
Auto precharge waveforms
A10 controls the selection of auto precharge during the read or write command cycle.
(write with auto precharge; BL = 4)
CLK
CMD
DQ
WE
D
0
D
D
D
3
1
2
Auto precharge starts*
(read with auto precharge; BL = 4)
CLK
CMD
Read data
DQ(CL2)
DQ(CL3)
Q
Q
Q
Q
3
0
1
2
Q
Q
Q
Q
3
0
1
2
Auto precharge starts*
The row active command of the precharge bank can be issued after t from this point. At burst read/ write with auto precharge, CAS interrupt of the same
*
RP
bank is illegal; other bank is described below.
12
ALLIANCE SEMICONDUCTOR
7/ 5/ 00
ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
