Software data protection enable algorithm, Software data protection disable algorithm, Software protected program cycle waveform – Rainbow Electronics AT29C1024 User Manual

Page 8

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AT29C1024

8

Software Data Protection
Enable Algorithm

(1)

Notes for software program code:

1.

Data Format: I/O15 - I/O0 (Hex);
Address Format: A14 - A0 (Hex).

2.

Write Protect state will be activated at end of write
period even if no other data is loaded.

3.

Write Protect state will be deactivated at end of
write period even if no other data is loaded.

4.

128 words of data MUST BE loaded.

Software Data Protection
Disable Algorithm

(1)

Software Protected Program Cycle Waveform

(1)(2)(3)

Note:

1.

A7 through A16 must specify the same 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.

LOAD DATA AAAA

TO

ADDRESS 5555

LOAD DATA 5555

TO

ADDRESS 2AAA

LOAD DATA A0A0

TO

ADDRESS 5555

LOAD DATA

TO

SECTOR (128 WORDS)

(4)

WRITES ENABLED

ENTER DATA

PROTECT STATE

(2)

LOAD DATA AAAA

TO

ADDRESS 5555

LOAD DATA 5555

TO

ADDRESS 2AAA

LOAD DATA 8080

TO

ADDRESS 5555

LOAD DATA AAAA

TO

ADDRESS 5555

LOAD DATA 5555

TO

ADDRESS 2AAA

LOAD DATA 2020

TO

ADDRESS 5555

LOAD DATA XXXX

TO

SECTOR (128 WORDS)

(4)

EXIT DATA

PROTECT STATE

(3)

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