Programming algorithm, Software protected program cycle waveform s, Page mode characteristics – Rainbow Electronics AT28BV256 User Manual
Page 7
AT28BV256
7
Programming Algorithm
Notes for software program code:
1.
Data Format: I/O7 - I/O0 (Hex);
Address Format: A14 - A0 (Hex).
2.
Data protect state will be re-activated at the end of
program cycle.
3.
1 to 64 bytes of data are loaded.
Software Protected Program Cycle Waveforms
Notes:
1.
A0 - A14 must conform to the addressing sequence for the first three bytes as shown above.
2.
A6 through A14 must specify the same page address during each high to low transition of WE (or CE) after the software
code has been entered.
3.
OE must be high only when WE and CE are both low.
Page Mode Characteristics
Symbol
Parameter
Min
Max
Units
t
WC
Write Cycle Time
10
ms
t
AS
Address Set-up Time
0
ns
t
AH
Address Hold Time
50
ns
t
DS
Data Set-up Time
50
ns
t
DH
Data Hold Time
0
ns
t
WP
Write Pulse Width
200
ns
t
BLC
Byte Load Cycle Time
150
µs
t
WPH
Write Pulse Width High
100
ns
LOAD DATA AA
TO
ADDRESS 5555
LOAD DATA 55
TO
ADDRESS 2AAA
LOAD DATA A0
TO
ADDRESS 5555
LOAD DATA XX
TO
ANY ADDRESS
(3)
LOAD LAST BYTE
TO
LAST ADDRESS
(3)
ENTER DATA
PROTECT STATE
WRITES ENABLED
(2)
t
AS
t
AH
t
WP
t
WPH
t
BLC
t
DH
t
WC
t
DS