11

0456H–FLASH–2/05

AT29C512

18. Software Data Protection

Enable Algorithm(1)

Notes:

1. Data Format: I/O7 - I/O0 (Hex);Address Format: A14

- A0 (Hex).

2. Data Protect state will be activated at end of program

cycle.

3. Data Protect state will be deactivated at end of pro-

gram period.

4. 128 bytes of data MUST BE loaded.

LOAD DATA AA

TO

ADDRESS 5555

LOAD DATA 55

TO

ADDRESS 2AAA

LOAD DATA A0

TO

ADDRESS 5555

LOAD DATA

TO

WRITES ENABLED

ENTER DATA

19. Software Data Protection

Disable Algorithm(1)

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 20

TO

ADDRESS 5555

LOAD DATA

TO

EXIT DATA

20. Software Protected Program Cycle Waveform

(1)(2)(3)

Notes:

1. A7 through A15 must specify the page address during each high-to-low transition of WE (or CE) after the software code has

been entered.

2. OE must be high when WE and CE are both low.

3. All bytes that are not loaded within the sector being programmed will be indeterminate.

OE

(1)

CE

WE

DATA

(3)

BYTE 0

BYTE 126

BYTE 127

t

DH

t

BLC

t

DS

t

WP

t

WPH

t

AH

A0-A6

A7-A15

(2)

t

WC

5555

2AAA

5555

AA

55

A0

t

AS

SECTOR ADDRESS

BYTE ADDRESS