Table of Contents
Advertisement
15.6.2
Software Protection
Software protection can be implemented by setting the RAMS bit in RAM control register
(RAMCR) and erase block register (EBR). When software protection is in effect, setting the P or E
bit in flash memory control register (FLMCR) does not cause a transition to program mode or
erase mode. (See table 15-9.)
Table 15-9 Software Protection
Item
Description
•
Emulation
Setting the RAMS bit in RAMCR sets the
2
protection*
program/erase-protected state for all blocks.
•
Block
Erase protection can be set for individual
specification
blocks by settings in erase block register
protection
(EBR).*
However, program protection is disabled.
•
Setting EBR to H'00 places all blocks in the
erase-protected state.
Notes: 1. Two modes: program-verify mode and erase-verify mode.
2. Programming to the RAM area that overlaps flash memory is possible.
3. All blocks become unerasable, and specification by block is impossible.
4. Set H'00 in the EBR bits, except for erase.
15.6.3
Error Protection
In error protection, an error is detected when this LSI runaway occurs during flash memory
programming/erasing*
algorithm, and the program/erase operation is aborted. Aborting the program/erase operation
prevents damage to the flash memory due to overprogramming or overerasing.
If the LSI malfunctions during flash memory programming/erasing, the FLER bit*
flash memory status register (FLMSR) and the error protection state is entered. The FLMCR and
3
EBR settings*
are retained, but program mode or erase mode is aborted at the point at which the
error occurred. When 1 is set in the FLER bit, transition to the program mode or erase mode
cannot be made even by setting the P and E bits in FLMCR. However, PV and EV bit in FLMCR
setting is enabled, and a transition can be made to verify mode.
Error protection is released only by a reset via the RES pin or a WDT reset, or in the hardware
standby mode.
4
1
, or operation is not performed in accordance with the program/erase
Function
Program Erase
2
3
No*
No*
—
No
2
is set to 1 in
1
Verify*
Yes
Yes
467
Advertisement
Table of Contents
