S29AL008D55BAI011 datasheet(22/55 Pages) SPANSION

22 / 55 page

S29AL008D

S29AL008D_00A3 June 16, 2005

Da t a

S h ee t

Note: See Table 5, on page 25 for program command sequence.

Figure 3. Program Operation

Chip Erase Command Sequence

Chip erase is a six bus cycle operation. The chip erase command sequence is ini-

tiated by writing two unlock cycles, followed by a set-up command. Two

additional unlock write cycles are then followed by the chip erase command,

which in turn invokes the Embedded Erase algorithm. The device does not require

the system to preprogram prior to erase. The Embedded Erase algorithm auto-

matically preprograms and verifies the entire memory for an all zero data pattern

prior to electrical erase. The system is not required to provide any controls or tim-

ings during these operations. Table 5, on page 25 shows the address and data

requirements for the chip erase command sequence.

Any commands written to the chip during the Embedded Erase algorithm are ig-

nored. Note that a hardware reset during the chip erase operation immediately

terminates the operation. The Chip Erase command sequence should be reiniti-

ated once the device returns to reading array data, to ensure data integrity.

The system can determine the status of the erase operation by using DQ7, DQ6,

DQ2, or RY/BY#. See Write Operation Status, on page 27 for information on

these status bits. When the Embedded Erase algorithm is complete, the device

returns to reading array data and addresses are no longer latched.

START

Write Program

Command Sequence

Data Poll

from System

Verify Data?

Yes

Last Address?

Yes

Programming

Completed

Increment Address

Embedded

Program

algorithm

in progress

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