HD64F2149 Datasheet, PDF (719/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

Table 22.10 Software Protection
Item
SWE bit protection
Block specification
protection
Description
• Clearing the SWE bit to 0 in FLMCR1 sets
the program/erase-protected state for all
blocks.
(Execute in on-chip RAM or external
memory.)
• Erase protection can be set for individual
blocks by settings in erase block registers
1 and 2 (EBR1, EBR2).
• Setting EBR1 and EBR2 to H'00 places all
blocks in the erase-protected state.
Functions
Program Erase
Yes
Yes
—
Yes
22.8.3 Error Protection
In error protection, an error is detected when MCU runaway occurs during flash memory
programming/erasing, or operation is not performed in accordance with the program/erase
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 MCU malfunctions during flash memory programming/erasing, the FLER bit is set to 1 in
FLMCR2 and the error protection state is entered. The FLMCR1, FLMCR2, EBR1, and EBR2
settings are retained, but program mode or erase mode is aborted at the point at which the error
occurred. Program mode or erase mode cannot be re-entered by re-setting the P or E bit. However,
PV and EV bit setting is enabled, and a transition can be made to verify mode.
FLER bit setting conditions are as follows:
• When flash memory is read during programming/erasing (including a vector read or instruction
fetch)
• Immediately after exception handling (excluding a reset) during programming/erasing
• When a SLEEP instruction (including software standby, sleep, subactive, subsleep and watch
mode) is executed during programming/erasing
• When the bus is released during programming/erasing
Error protection is released only by a reset and in hardware standby mode.
Figure 22.14 shows the flash memory state transition diagram.
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