22.8
Protection
There are three kinds of flash memory program/erase protection: hardware protection, software
protection, and error protection.
22.8.1
Hardware Protection
Hardware protection refers to a state in which programming/erasing of flash memory is forcibly
disabled or aborted. Hardware protection is reset by settings in flash memory control register 1
(FLMCR1), flash memory control register 2 (FLMCR2), erase block register 1 (EBR1), and erase
block register 2 (EBR2). The FLMCR1, FLMCR2, EBR1, and EBR2 settings are retained in the
error-protected state. (See table 22-8.)
Table 22-8 Hardware Protection
Item
FWE pin protection
Reset/standby
protection
Description
•
When a low level is input to the FWE pin,
FLMCR1, FLMCR2, (except bit FLER)
EBR1, and EBR2 are initialized, and the
program/erase-protected state is entered.
•
In a power-on reset (including a WDT
power-on reset) and in standby mode,
FLMCR1, FLMCR2, EBR1, and EBR2 are
initialized, and the program/erase-
protected state is entered.
•
In a reset via the RES pin, the reset state
is not entered unless the RES pin is held
low until oscillation stabilizes after
powering on. In the case of a reset during
operation, hold the RES pin low for the
RES pulse width specified in the AC
Characteristics section.
Functions
Program
Erase
Yes
Yes
Yes
Yes
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