D12320VF25V Datasheet, PDF (772/1146 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 17 ROM
17.25 Protection
There are three kinds of flash memory program/erase protection: hardware, software protection,
and error protection.
17.25.1 Hardware Protection
Programming and erasing of flash memory is forcibly disabled or suspended by hardware
protection. In this state, the downloading of an on-chip program and initialization of the flash
memory are possible. However, an activated program for programming or erasure cannot program
or erase locations in a user MAT, and the error in programming/erasing is reported in the
parameter FPFR.
Table 17.54 Hardware Protection
Item
Reset/standby
protection
Function to Be Protected
Description
Download Program/Erase
• A power-on reset (including a power- Yes
Yes
on reset by the WDT) and entry to
standby mode reinitialize the
program/erase interface register and
the device enters a program/erase-
protected state.
• Resetting by means of the RES pin
after power is initially supplied will not
make the device enter the reset state
unless the RES pin is held low until
oscillation has stabilized. In the case
of a reset during operation, hold the
RES pin low for the RES pulse width
that is specified in the section on AC
characteristics section. If the device is
reset during programming or erasure,
data values in the flash memory are
not guaranteed. In this case, after
keeping the RES pin low for at least
100 μs, execute erasure and then
execute programming again.
Rev.7.00 Feb. 14, 2007 page 738 of 1108
REJ09B0089-0700