M16CSLASH62 datasheet(247/615 Pages) RENESAS

247 / 615 page

CPU Rewrite Mode (Flash Memory Version)

Mitsubishi microcomputers

M16C / 62A Group

SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

1-228

Write 7716

Write D016

block address

SR4 = 0?

Lock bit program

completed

Lock bit program in

error

YES

Start

RY/BY status flag

= 1?

YES

Erase 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 status

When the lock bit disable select bit of the flash memory control register 0 = 1, all blocks are erased no

matter how the lock bit is set. On the other hand, when the lock bit disable select bit = 0, the function of

the lock bit is 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 the

lock bit for the specified block to 0 (locked).

Figure 1.26.6 shows an example of a lock bit program flowchart. The status of the lock bit (lock bit

data) 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 register

or 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 the

data protect function is detailed.

Figure 1.26.6. Lock bit program flowchart

M16C/62 데이터시트(PDF) 247 Page - Renesas Technology Corp