Rainbow Electronics AT29C512 - Manual (Page 10)

10
AT29C512
0456E–FLASH–5/02
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
PAGE (128 BYTES) (4)
WRITES ENABLED
ENTER DATA
PROTECT STATE (2)
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
PAGE (128 BYTES) (4)
EXIT DATA
PROTECT STATE (3)
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