M16C/62 Group DATASHEET

CPU Rewrite Mode (Flash Memory Version)Mitsubishi microcomputersM16C / 62 GroupSINGLE-CHIP 16-BIT CMOS MICROCOMPUTERErase All Unlock Blocks Command (A716/D016)By writing the command code “A716” in the first bus cycle and the confirmation command code “D016”in the second bus cycle that follows, the system starts erasing blocks successively.Whether the erase all unlock blocks command is terminated can be confirmed by reading the statusregister or the flash memory control register 0, in the same way as for block erase. Also, the statusregister can be read out to know the result of the auto erase operation.When the lock bit disable bit of the flash memory control register 0 = 1, all blocks are erased no matterhow the lock bit is set. On the other hand, when the lock bit disable bit = 0, the function of the lock bitis effective and only nonlocked blocks (where lock bit data = 1) are erased.Lock Bit Program Command (7716/D016)By writing the command code “7716” in the first bus cycle and the confirmation command code “D016”in the second bus cycle that follows to the block address of a flash memory block, the system sets thelock bit for the specified block to 0 (locked).Figure 1.29.6 shows an example of a lock bit program flowchart. The status of the lock bit (lock bitdata) can be read out by a read lock bit status command.Whether the lock bit program command is terminated can be confirmed by reading the status registeror the flash memory control register 0, in the same way as for page program.For details about the function of the lock bit and how to reset the lock bit, refer to the section where thedata protect function is detailed.StartWrite 7716Write D016block addressRY/BY status flag= 1?NOYESSR4 = 0?YESLock bit programcompletedNOLock bit program inerrorFigure 1.29.6. Lock bit program flowchart244