BRIGHT
Microelectronics
Inc.
Preliminary BM29F400T/BM29F400B
Sector Unprotect
The BM29F400 also features a sector unprotect mode, so that protected sectors may be unprotected
to incorporate any changes in the code. Protecting all sectors is necessary before unprotecting any
sector(s). Sector unprotection is accomplished in a PROM programmer.
START
Write Program Command Sequence
(see below)
/Data Polling Device
NO
Increment Address
Last Address
?
YES
Programming Completed
Program Command Sequence (Address/Command)
5555H/AAH
2AAAH/55H
5555H/A0H
Program Address/ Program Data
Figure 1. Internal Programming Algorithm
A Winbond Company
Publication Release Date: May 1999
Revision A1
- 17 -
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