M65KA128AL datasheet(13/53 Pages) STMICROELECTRONICS

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M65KA128AL

Operations

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3.3

Burst Write

The Write Command is used to switch the device to Burst Write mode (see Section 4.5:

Write command for details). In Burst Write mode the data is input in bursts synchronized

with the clock. A valid Burst Write is initiated by driving E, CAS and W Low, VIL, and by

driving RAS High, VIH, at the positive edge of the clock signal, K.

Burst Write can be accompanied by an Auto Precharge cycle depending on the state of the

A10 Address Input. If A10 is High (set to ‘1’) when the Write command is issued, the Write

operation will be followed by an Auto Precharge cycle.

During Burst Write operation, the memory writes data to the activated bank. As for Burst

Read, different Burst Types and Lengths can be utilized, programmed in the same fashion.

3.4

Self Refresh

In Self Refresh mode, the data contained in the Low Power SDRAM memory array is

retained and refreshed. The Low Power SDRAM refresh cycles are asynchronous.

The Self-Refresh mode is entered by driving KE Low (set to ‘0’), with E, RAS, and CAS Low,

and W High (set to ‘1’). When in this mode, the device is not clocked any more.

The Self Refresh mode is exited by driving KE from Low to High, with E High, RAS, CAS

and W Don’t Care, or with E Low and RAS, CAS and W High.

3.5

Auto Refresh

The Auto Refresh mode is used to refresh the Low Power SDRAM in normal operation

mode whenever needed.

During an auto refresh operation, KE must be kept High, VIH and the address bits are “Don’t

Care” because the specific address bits are generated by the internal refresh address

counter.

3.6

Power-Down

In Power-Down mode, the current is reduced the Standby current.

For the memory to enter the Power-Down mode, KE must be held Low (set to ‘0’), after the

Precharge Time tRP, with E High (set to ‘1’), RAS, CAS and W Don’t Care, or with E Low,

RAS, CAS and W High.

The Power-Down mode is exited by driving KE High, with E High, RAS, CAS and W Don’t

Care, or with E Low and RAS, CAS and W High.

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