IS42S16128 View Datasheet(PDF) - Integrated Silicon Solution

Part Name

Description

Manufacturer

IS42S16128

128K Words x 16 Bits x 2 Banks (4-MBIT) SYNCHRONOUS DYNAMIC RAM

Integrated Silicon Solution 

IS42S16128

ISSI ®

Self-Refresh Command

(CS, RAS, CAS, CKE = LOW, WE = HIGH)

This command executes the self-refresh operation. The

row address to be refreshed, the bank, and the refresh

interval are generated automatically internally during this

operation. The self-refresh operation is started by drop-

ping the CKE pin from HIGH to LOW. The self-refresh

operation continues as long as the CKE pin remains LOW

and there is no need for external control of any other pins.

The self-refresh operation is terminated by raising the

CKE pin from LOW to HIGH. The next command cannot

be executed until the device internal recovery period (tRC)

has elapsed. After the self-refresh, since it is impossible

to determine the address of the last row to be refreshed,

an auto-refresh should immediately be performed for all

addresses (1024 cycles).

Both banks must be placed in the idle state before

executing this command.

Burst Stop Command

(CS, WE, = LOW, RAS, CAS = HIGH)

The command forcibly terminates burst read and write

operations. When this command is executed during a

burst read operation, data output stops after the CAS

latency period has elapsed.

No Operation

(CS, = LOW, RAS, CAS, WE = HIGH)

This command has no effect on the device.

Device Deselect Command

(CS = HIGH)

This command does not select the device for an object of

operation. In other words, it performs no operation with

respect to the device.

Power-Down Command

(CKE = LOW)

When both banks are in the idle (inactive) state, or when

at least one of the banks is not in the idle (inactive) state,

this command can be used to suppress device power

dissipation by reducing device internal operations to the

absolute minimum. Power-down mode is started by drop-

ping the CKE pin from HIGH to LOW. Power-down mode

continues as long as the CKE pin is held low.

Power-Down Command (cont.)

All pins other than the CKE pin are invalid and none of the

other commands can be executed in this mode. The

power-down operation is terminated by raising the CKE

pin from LOW to HIGH. The next command cannot be

executed until the recovery period (tCKA) has elapsed.

Since this command differs from the self-refresh com-

mand described above in that the refresh operation is not

performed automatically internally, the refresh operation

must be performed within the refresh period (tREF). Thus

the maximum time that power-down mode can be held is

just under the refresh cycle time.

Clock Suspend

(CKE = LOW)

This command can be used to stop the device internal

clock temporarily during a read or write cycle. Clock

suspend mode is started by dropping the CKE pin from

HIGH to LOW. Clock suspend mode continues as long as

the CKE pin is held LOW. All input pins other than the CKE

pin are invalid and none of the other commands can be

executed in this mode. Also note that the device internal

state is maintained. Clock suspend mode is terminated by

raising the CKE pin from LOW to HIGH, at which point

device operation restarts. The next command cannot be

executed until the recovery period (tCKA) has elapsed.

Since this command differs from the self-refresh com-

mand described above in that the refresh operation is not

performed automatically internally, the refresh operation

must be performed within the refresh period (tREF). Thus

the maximum time that clock suspend mode can be held

is just under the refresh cycle time.

Integrated Silicon Solution, Inc. — 1-800-379-4774

11

Rev. A

03/13/00

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