X28C010 Datasheet, PDF (7/23 Pages) Xicor Inc. – 5 Volt, Byte Alterable E2PROM

Write Data AA
to Address
5555
Write Data 55
to Address
2AAA
Write Data A0
to Address
5555
X28C010
Regardless of whether the device has previously been
protected or not, once the software data protection algorithm
is used and data has been written, the X28C010 will
automatically disable further writes unless another command
is issued to cancel it. If no further commands are issued the
X28C010 will be write protected during power-down and
after any subsequent power-up. The state of A₁₅ and A₁₆
while executing the algorithm is don’t care.
Note: Once initiated, the sequence of write operations
should not be interrupted.
Write Data XX
to Any
Address
Write Last
Byte
Last Address
Optional
Byte/Page
Load Operation
After t_WC
Re-Enters Data
Protected State
FIGURE 7. WRITE SEQUENCE FOR SOFTWARE DATA
PROTECTION
Resetting Software Data Protection
V_CC
Data
Addr
AA
5555
CE
55
2AAA
80
5555
AA
5555
55
2AAA
20
5555
≥ t_WC
Standard
Operating
Mode
WE
FIGURE 8. RESET SOFTWARE DATA PROTECTION TIMING SEQUENCE
7
FN8105.0
May 11, 2005