M65KA512AB datasheet(18/55 Pages) STMICROELECTRONICS

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Commands

M65KA512AB

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4.11

Auto Refresh command

The Auto Refresh command is used to put the device in Auto refresh mode (see Section 3.5:

Auto Refresh and Figure 24: Auto refresh ac waveforms).

4.12

Self Refresh command

The purpose of the Self Refresh command is used to put the device in Self Refresh mode to

retain and refresh the data contained in the Low-Power SDRAM memory array. In Self

Refresh mode, the Low-Power SDRAM runs Refresh cycles asynchronously.

The Self Refresh cycle is performed according to the Extended Mode Register bits EMR0 to

EMR2 that configure the part of the memory array being refreshed (Partial Array Self

Refresh).

For more information on how the command is issued, refer to Figure 25: Self refresh ac

waveforms.

4.13

Power-Down command

The Power-Down command is used to put the device in Power-Down mode where the

operating current is reduced to the Standby current.

All banks must be precharged and a minimum time of tRP must elapse before issuing the

Power-Down command.

4.14

Deep Power-Down command

The Deep Power-Down command is used to switch the Low-Power SDRAM to Deep Power-

Down Mode. This mode provides maximum power reduction as it cuts the power of the

entire memory array of the device. For more information on how the command is issued and

its exit sequence, see Section 3.7: Deep Power-Down, Figure 26: Deep Power-Down Entry

ac waveforms, and Figure 27: Deep Power-Down Exit ac waveforms.

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