MB89120/120A Series
s PROGRAMMING TO THE EPROM ON THE MB89P131
The MB89P131 is a one-time PROM version of the MB89121.
1. Features
• 4-Kbyte PROM on chip
• Equivalency to the MBM27C256A in EPROM mode (when programmed with the EPROM programmer)
2. Memory Space
Memory space in EPROM mode is diagrammed below :
Address
0000H
F000H
Single chip
I/O
Not available
RAM
Not available
EPROM mode
(Corresponding addresses in the EPROM programmer)
0000H
7000H
Not available
PROM
4 KB
EPROM
32 KB
FFFFH
7FFFH
3. Programming to the EPROM
In EPROM mode the MB89P131 functions equivalent to the MBM27C256A. This allows the EPROM to be
programmed with a general-purpose EPROM programmer by using the dedicated socket adapter. Note, how-
ever, that the electronic signature mode cannot be used.
• Programming procedure
(1) Set the EPROM programmer to MBM27C256A.
(2) Load program data into the EPROM programmer at 7000H to 7FFFH (note that addresses F000H to
FFFFH while operating as a single chip correspond to 7000H to 7FFFH in EPROM mode) .
(3) Program with the EPROM programmer.
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