68HC705JJ7_1 Datasheet, PDF (177/230 Pages) Freescale Semiconductor, Inc – General Release Specification

Freescale Semiconductor, Inc.
Personality EPROM
PEPROM Erasing
Reading the PEPROM is easiest when each PEPROM column contains
one byte. Selecting a row 0 bit selects the first bit, and incrementing the
PEPROM bit select register (PEBSR) selects the next bit in row 1 from
the same column. Incrementing PEBSR seven more times selects the
remaining bits of the column and ends up selecting the bit in row 0 of the
next column, thereby setting the row 0 flag, PEPRZF.
NOTE:
A PEPROM byte that has been read can be transferred to the
personality EPROM bit select register (PEBSR) as a temporary storage
location such that subsequent reads of the PEBSR quickly yield that
PEPROM byte.
12.6 PEPROM Erasing
MCUs with windowed packages permit PEPROM erasure with
ultraviolet light. Erase the PEPROM 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 a PEPROM bit is a logic zero.
MC68HC705JJ7/MC68HC705JP7 — Rev. 3.0
General Release Specification
Personality EPROM
For More Information On This Product,
Go to: www.freescale.com