IS42S16100E, IC42S16100E
Read With Auto-Precharge
The read with auto-precharge command first executes a
burst read operation and then puts the selected bank in
the precharged state automatically. After the precharge
completes, the bank goes to the idle state. Thus this
command performs a read command and a precharge
command in a single operation.
three, the precharge operation starts on two clock cycles
before the last burst data is output (tp q l = –2). Therefore,
the selected bank can be made active after a delay of tr p
from the start position of this precharge operation.
The selected bank must be set to the active state before
executing this command.
During this operation, the delay period (tp q l ) between the
last burst data output and the start of the precharge opera-
tion differs depending on the CAS latency setting.
The auto-precharge function is invalid if the burst length
is set to full page.
WhentheCASlatencysettingistwo, theprechargeopera-
tion starts on one clock cycle before the last burst data is
output (tp q l = –1). When the CAS latency setting is
CAS Latency
3
2
tp q l
–2
–1
CLK
COMMAND
DQ
READA 0
ACT 0
t
PQL
DOUT
0
D
OUT
1
D
OUT DOUT 3
2
tRP
PRECHARGE START
READ WITH AUTO-PRECHARGE
(BANK 0)
CAS latency = 2, burstlength = 4
CLK
COMMAND
DQ
ACT 0
READA 0
t
PQL
DOUT
0
D
OUT
1
D
OUT
2
DOUT 3
t
RP
READ WITH AUTO-PRECHARGE
(BANK 0)
PRECHARGE START
CAS latency = 3, burstlength = 4
26
Integrated Silicon Solution, Inc. — www.issi.com
Rev. C
01/22/08
ISSI [ INTEGRATED SILICON SOLUTION, INC ]
