W29C020

Publication Release Date: February 1998

- 9 -

Revision A3

Command Codes for Boot Block Lockout Enable

BYTE SEQUENCE

BOOT BLOCK LOCKOUT FEATURE SET

ON FIRST 8K ADDRESS BOOT BLOCK

BOOT BLOCK LOCKOUT FEATURE SET

ON LAST 8K ADDRESS BOOT BLOCK

ADDRESS

DATA

ADDRESS

DATA

0 Write

5555H

AAH

5555H

AAH

1 Write

2AAAH

55H

2AAAH

55H

2 Write

5555H

80H

5555H

80H

3 Write

5555H

AAH

5555H

AAH

4 Write

2AAAH

55H

2AAAH

55H

5 Write

5555H

40H

5555H

40H

6 Write

00000H

00H

3FFFFH

FFH

Pause 10 mS

Pause 10 mS

Boot Block Lockout Enable Acquisition Flow

Load data AA

to

address 5555

Load data 55

to

address 2AAA

Load data 80

to

address 5555

Load data AA

to

address 5555

Load data 55

to

address 2AAA

Load data 40

to

address 5555

Pause 10 mS

Load data 00

to

address 00000

Boot Block Lockout

Feature Set on First 8K

Address Boot Block

Boot Block Lockout

Feature Set on Last 8K

Address Boot Block

Load data AA

to

address 5555

Load data 55

to

address 2AAA

Load data 80

to

address 5555

Load data AA

to

address 5555

Load data 55

to

address 2AAA

Load data 40

to

address 5555

Pause 10 mS

Load data FF

to

address 3FFFF

Notes for boot block lockout enable:

1. Data Format: DQ7

−DQ0 (Hex)

2. Address Format: A14

−A0 (Hex)

3. If you have any questions about this commend sequence, please contact the local distributor or Winbond Electronics Corp.