M29W040B

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Table 5. Commands

Note: X Don’t Care, PA Program Address, PD Program Data, BA Any address in the Block.

All values in the table are in hexadecimal.

The Command Interface only uses address bits A0-A10 to verify the commands, the upper address bits are Don’t Care.

Read/Reset. After a Read/Reset command, read the memory as normal until another command is issued.

Auto Select. After an Auto Select command, read Manufacturer ID, Device ID or Block Protection Status.

Program, Unlock Bypass Program, Chip Erase, Block Erase. After these commands read the Status Register until the Program/Erase

Controller completes and the memory returns to Read Mode. Add additional Blocks during Block Erase Command with additional Bus Write

Operations until the Timeout Bit is set.

Unlock Bypass. After the Unlock Bypass command issue Unlock Bypass Program or Unlock Bypass Reset commands.

Unlock Bypass Reset. After the Unlock Bypass Reset command read the memory as normal until another command is issued.

Erase Suspend. After the Erase Suspend command read non-erasing memory blocks as normal, issue Auto Select and Program commands

on non-erasing blocks as normal.

Erase Resume. After the Erase Resume command the suspended Erase operation resumes, read the Status Register until the Program/

Erase Controller completes and the memory returns to Read Mode.

Command

Bus Write Operations

1st

2nd

3rd

4th

5th

6th

Addr

Data

Addr

Data

Addr

Data

Addr

Data

Addr

Data

Addr

Data

Read/Reset

1X

F0

3555

AA

2AA

55

X

F0

Auto Select

3

555

AA

2AA

55

555

90

Program

4

555

AA

2AA

55

555

A0

PA

PD

Unlock Bypass

3

555

AA

2AA

55

555

20

Unlock Bypass

Program

2

X

A0

PA

PD

Unlock Bypass Reset

2

X

90

X

00

Chip Erase

6

555

AA

2AA

55

555

80

555

AA

2AA

55

555

10

Block Erase

6+

555

AA

2AA

55

555

80

555

AA

2AA

55

BA

30

Erase Suspend

1

X

B0

Erase Resume

1

X

30

Chip Erase Command. The Chip Erase com-

mand can be used to erase the entire chip. Six Bus

Write operations are required to issue the Chip

Erase Command and start the Program/Erase

Controller.

If any blocks are protected then these are ignored

and all the other blocks are erased. If all of the

blocks are protected the Chip Erase operation ap-

pears to start but will terminate within about 100µs,

leaving the data unchanged. No error condition is

given when protected blocks are ignored.

During the erase operation the memory will ignore

all commands. It is not possible to issue any com-

mand to abort the operation. Typical chip erase

times are given in Table 6. All Bus Read opera-

tions during the Chip Erase operation will output

the Status Register on the Data Inputs/Outputs.

See the section on the Status Register for more

details.

After the Chip Erase operation has completed the

memory will return to the Read Mode, unless an

error has occurred. When an error occurs the

memory will continue to output the Status Regis-

ter. A Read/Reset command must be issued to re-

set the error condition and return to Read Mode.

The Chip Erase Command sets all of the bits in un-

protected blocks of the memory to ‘1’. All previous

data is lost.