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Software reset – Rainbow Electronics AT45DB021E User Manual

Page 36

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36

AT45DB021E [PRELIMINARY DATASHEET]

8789B–DFLASH–11/2012

13.

Software Reset

In some applications, it may be necessary to prematurely terminate a program or erase cycle early rather than wait the
hundreds of microseconds or milliseconds necessary for the program or erase operation to complete normally. The
Software Reset command allows a program or erase operation in progress to be ended abruptly and returns the device
to an idle state.

To perform a Software Reset, the CS pin must be asserted and a 4-byte command sequence of F0h, 00h, 00h, and 00h
must be clocked into the device. Any additional data clocked into the device after the last byte will be ignored. When the
CS pin is deasserted, the program or erase operation currently in progress will be terminated within a time t

SWRST

. Since

the program or erase operation may not complete before the device is reset, the contents of the page being programmed
or erased cannot be guaranteed to be valid.

The Software Reset command has no effect on the states of the Sector Protection Register, the Sector Lockdown
Register, or the Buffer and page size configuration.

The complete 4-byte opcode must be clocked into the device before the CS pin is deasserted; otherwise, no reset
operation will be performed.

Table 13-1. Software Reset

Figure 13-1. Software Reset

Command

Byte 1

Byte 2

Byte 3

Byte 4

Software Reset

F0h

00h

00h

00h

CS

SI

F0h

00h

00h

00h

Each transition represents eight bits