MC68HC705JP7 Datasheet, PDF (190/242 Pages) Motorola, Inc – HCMOS Microcontroller Unit

EPROM/OTPROM
Freescale Semiconductor, Inc.
13.4.2 EPMSEC Programming
The EPMSEC bit is programmable. To program the EPMSEC bit, the
desired state must be written to the COP address and then the MPGM
bit in the EPROG register must be used. The following sequence will
program the EPMSEC bit:
1. Write the desired data to bit 7 of the COPR location ($1FF0).
2. Apply the programming voltage to the IRQ/V_PP pin.
3. Set the MPGM bit in the EPROG.
4. Wait for the programming time, t_MPGM.
5. Clear the MPGM bit in the EPROG.
6. Remove the programming voltage from the IRQ/V_PP pin.
Once the EPMSEC bit has been programmed to a logic 1, access to the
contents of the EPROM and MOR in the expanded non-user modes will
be denied. It is therefore recommended that the user EPROM and MOR
in the part first be programmed and fully verified before setting the
EPMSEC bit.
13.5 EPROM Erasing
MCUs with windowed packages permit EPROM erasing with ultraviolet
light. Erase the EPROM by exposing it to 15 Ws/cm² of ultraviolet light
with a wavelength of 2537 angstroms. Position the ultraviolet light
source 1 inch from the window. Do not use a shortwave filter. The erased
state of an EPROM bit is a logic 0.
NOTE: Unlike many commercial EPROMs, an erased EPROM byte in the MCU
will read as $00. All unused locations should be programmed as 0s.
Advance Information
190
MC68HC705JJ7 • MC68HC705JP7 — REV 4
EPROM/OTPROM
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