Freescale Semiconductor, Inc.
Pe rsona lity EPROM
12.4 PEPROM Prog ra m m ing
Factory-provided software for programming the PEPROM is available
through the Motorola Freeware Bulletin Board Service (BBS). The
number is (512) 891-FREE. After making the connection, type bbs in
lowercase letters. Then press the return key to start the BBS software.
NOTE: While the PEPGM bit is set and the V voltage level is applied to the
PP
IRQ/V pin, do not access bits that are to be left unprogrammed
PP
(erased).
To program the PEPROM bits properly, the V voltage must be greater
DD
than 4.5 Vdc.
The PEPROM can also be programmed by user software with the V
PP
voltage level applied to the IRQ/V pin. The following sequence shows
PP
how to program each PEPROM bit:
1. Select a PEPROM bit by writing to the PEBSR.
2. Set the PEPGM bit in the PESCR.
3. Wait for the programming time, t
4. Clear the PEPGM bit.
.
EPGM
5. Move to next PEPROM bit to be programmed in step 1.
12.5 PEPROM Re a d ing
The following sequence shows how to read the PEPROM:
1. Select a bit by writing to the PEBSR.
2. Read the PEDATA bit in the PESCR.
3. Store the PEDATA bit in RAM or in a register.
4. Select another bit by changing the PEBSR.
5. Continue reading and storing the PEDATA bits until the required
personality EPROM data is retrieved and stored.
General Release Specification
MC68HC705JJ7/MC68HC705JP7 — Rev. 3.0
Personality EPROM
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