Rev. 1.0, 02/00, page 153 of 1141
7.6
Flash Memory Protection
There are three kinds of flash memory program/erase protection: hardware protection, software
protection, and error protection.
7.6.1
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 registers 1
and 2 (FLMCR1, FLMCR2) and erase block registers 1 and 2 (EBR1, EBR2). (See table 7.6.)
In error protected state, the FLMCR1, FLMCR2, EBR1, and EBR2 settings are maintained.
Table 7.6
Hardware Protection
Functions
Item
Description
Program
Erase
FWE pin
protection
•
When a low level is input to the FWE pin, FLMCR1,
FLMCR2 (excluding the FLER bit), EBR1, and EBR2
are initialized, and the program/erase-protected state
is entered
Yes
Yes
Reset/standby
protection
•
In a reset (including a WDT overflow 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
5(6
pin, the reset state is not
entered unless the
5(6
pin is held low until oscillation
stabilizes after powering on. In the case of a reset
during operation, hold the
5(6
pin low for the
5(6
pulse width specified in the AC characteristics
Yes
Yes