Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Appendix Standard Serial I/O Mode (Flash Memory Version)
Data Protection (Block Lock)
Each of the blocks in Figure 1.30.1 have a nonvolatile lock bit that specifies protection (block lock) against
erasing/writing. A block is locked (writing “0” for the lock bit) with the lock bit program command. Also, the
lock bit of any block can be read with the read lock bit status command.
Block lock disable/enable is determined by the status of the lock bit itself and execution status of the lock
bit disable and lock enable bit commands.
(1) After the reset has been cancelled and the lock bit enable command executed, the specified block
can be locked/unlocked using the lock bit (lock bit data). Blocks with a “0” lock bit data are locked
and cannot be erased or written in. On the other hand, blocks with a “1” lock bit data are unlocked
and can be erased or written in.
(2) After the lock bit enable command has been executed, all blocks are unlocked regardless of lock bit
data status and can be erased or written in. In this case, lock bit data that was “0” before the block
was erased is set to “1” (unlocked) after erasing, therefore the block is actually unlocked with the
lock bit.
0C000016
Block 6 : 64K byte
0D000016
Block 5 : 64K byte
0E000016
Block 4 : 64K byte
0F000016
Flash memory
size
Block 3 : 32K byte
Flash memory
start address
0F800016
0FA00016
256K byte
0C000016
Block 2 : 8K byte
Block 1 : 8K byte
Block 0 : 16K byte
0FC00016
0FFFFF16
User ROM area
Figure 1.31.18. Blocks in the user area
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