X28HC256 Xicor, X28HC256 Datasheet - Page 8

• Manufacturer Part Number: X28HC256
• Description: 5 Volt/ Byte Alterable E2PROM
• Manufacturer: Xicor

X28HC256
RESETTING SOFTWARE DATA PROTECTION
Figure 8. Reset Software Data Protection Timing Sequence
Figure 9. Write Sequence for resetting
Software Data Protection
DATA
ADDRESS
V CC
WE
CE
5555
AA
WRITE DATA AA
WRITE DATA 55
WRITE DATA AA
WRITE DATA 55
WRITE DATA 20
UNPROTECTED
WRITE DATA 80
TO ADDRESS
TO ADDRESS
TO ADDRESS
TO ADDRESS
TO ADDRESS
TO ADDRESS
AFTER t WC ,
RE-ENTERS
STATE
2AAA
2AAA
5555
5555
5555
5555
2AAA
55
5555
80
3859 FHD F19
5555
AA
8
In the event the user wants to deactivate the software
data protection feature for testing or reprogramming in
an E
rithm will reset the internal protection circuit. After t
the X28HC256 will be in standard operating mode.
Note: Once initiated, the sequence of write operations
2AAA
55
2
PROM programmer, the following six step algo-
should not be interrupted.
5555
20
t WC
STANDARD
OPERATING
MODE
3859 FHD F18
WC
,