is42s16128 Integrated Silicon Solution, Inc., is42s16128 Datasheet - Page 23

• Manufacturer Part Number: is42s16128
• Description: 128k Words Bits Banks Sdram
• Manufacturer: Integrated Silicon Solution, Inc.

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.
During this operation, the delay period (t
last burst data output and the start of the precharge
operation differs depending on the CAS latency setting.
When the CAS latency setting is one, the precharge
operation starts a the same time as the last burst data is
output (t
Integrated Silicon Solution, Inc. — 1-800-379-4774
Rev. A
03/13/00
IS42S16128
CAS latency = 2, burst length = 4
CAS latency = 3, burst length = 4
PQL
COMMAND
COMMAND
= 0). When the CAS latency setting is two,
READ WITH AUTO-PRECHARGE
READ WITH AUTO-PRECHARGE
CLK
CLK
I/O
I/O
(BANK 0)
(BANK 0)
READA 0
READA 0
PQL
) between the
D
OUT
PRECHARGE START
PRECHARGE START
0
D
D
OUT
OUT
0
1
the precharge operation starts on one clock cycle before
the last burst data is output (t
latency setting is three, the precharge operation starts on
two clock cycles before the last burst data is output
(t
active after a delay of t
precharge operation.
The selected bank must be set to the active state before
executing this command.
The auto-precharge function is invalid if the burst length
is set to full page.
PQL
D
D
OUT
OUT
= –2). Therefore, the selected bank can be made
t
PQL
1
2
CAS Latency
t
D
D
RP
OUT
t
OUT
t
PQL
PQL
2
3
t
RP
D
ACT 0
RP
OUT
from the start position of this
3
PQL
–2
= –1). When the CAS
3
ISSI
ACT 0
–1
2
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