is42s16128 Integrated Silicon Solution, Inc., is42s16128 Datasheet - Page 28

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

Precharge
The precharge command sets the bank selected by pin A9
to the precharged state. This command can be executed
at a time t
mand to the same bank. The selected bank goes to the
idle state at a time t
precharge command, and an active command can be
executed again for that bank.
If pin A8 is low when this command is executed, the bank
selected by pin A9 will be precharged, and if pin A8 is
HIGH, both banks will be precharged at the same time.
This input to pin A9 is ignored in the latter case.
28
IS42S16128
CAS latency = 2, burst length = 4
CAS latency = 3, burst length = 4
RAS
COMMAND
COMMAND
following the execution of an active com-
CLK
CLK
I/O
I/O
RP
following the execution of the
READ (CA=A, BANK 0)
READ (CA=A, BANK 0)
READ A0
READ A0
PRECHARGE (BANK 0)
D
OUT
A0
D
D
PRE 0
PRE 0
OUT
OUT
A0
A1
PRECHARGE (BANK 0)
Read Cycle Interruption
Using the Precharge Command
A read cycle can be interrupted by the execution of the
precharge command before that cycle completes. The
delay time (t
command to the completion of the burst output is the clock
cycle of CAS latency.
Integrated Silicon Solution, Inc. — 1-800-379-4774
D
t
D
RQL
OUT
OUT
CAS Latency
A1
A2
t
RQL
t
D
RQL
RQL
OUT
HI-Z
) from the execution of the precharge
A2
HI-Z
3
3
ISSI
2
2
03/13/00
Rev. A
®