at29c040a ATMEL Corporation, at29c040a Datasheet - Page 11

• Manufacturer Part Number: at29c040a
• Description: At29c040a 4-megabit 512k X 8 5-volt Only 256-byte Sector Flash Memory
• Manufacturer: ATMEL Corporation

20. Software Protected Program Cycle Waveform
Notes:
18. Software Data Protection
Notes:
0333K–FLASH–2/05
Enable Algorithm
1. A8 through A18 must specify the sector address during each high to low transition of WE (or CE) after the software code has
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.
1. Data Format: I/O7 - I/O0 (Hex);
2. Data Protect state will be activated at end of program
3. Data Protect state will be deactivated at end of
4. 256 bytes of data MUST BE loaded.
been entered.
Address Format: A14 - A0 (Hex).
cycle.
program period.
PAGE (256 BYTES)
ADDRESS 2AAA
LOAD DATA AA
ADDRESS 5555
ADDRESS 5555
LOAD DATA A0
LOAD DATA 55
LOAD DATA
TO
TO
TO
TO
(4)
(1)
WRITES ENABLED
ENTER DATA
PROTECT STATE
(2)
19. Software Data Protection
Disable Algorithm
(1)(2)(3)
PAGE (256 BYTES)
ADDRESS 2AAA
ADDRESS 2AAA
LOAD DATA AA
ADDRESS 5555
ADDRESS 5555
LOAD DATA AA
ADDRESS 5555
ADDRESS 5555
LOAD DATA 55
LOAD DATA 80
LOAD DATA 55
LOAD DATA 20
LOAD DATA
TO
TO
TO
TO
TO
TO
TO
(4)
EXIT DATA
PROTECT STATE
(1)
AT29C040A
(3)
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