M32CSLASH8B datasheet(331/406 Pages) RENESAS

331 / 406 page

Under development

M32C/8B Group

23. Flash Memory

Preliminary specification

Specifications in this manual are tentative and subject to change.

REJ09B0450-0050 Rev.0.50 Oct 31, 2008

Page 314 of 385

(6) Lock Bit Program Command

The lock bit program command is used to set the lock bit of a given block to 0 (locked).

By writing the command code xx77h in the first bus cycle and xxD0h to the highest-order even address of a

block to be locked in the second bus cycle, the lock bit of the specified block becomes 0. The address specified

in the first bus cycle must be the same highest-order even address of the block specified in the second bus cycle.

Figure 23.11 shows a flow chart of lock bit program command. Execute the read lock bit status command to

read lock bit status (lock bit data).

The FMR00 bit in the FMR0 register can be used to determine whether a lock bit program operation has been

completed or not.

Refer to 23.3.1 Lock bit Protect Function for information on lock bit functions and how to set it to 1

(unlocked).

In EW1 mode, do not execute this command to the block where the rewrite control program is stored.

In EW0 mode, the flash memory enters read status register mode when a program operation starts.

Figure 23.11

Lock Bit Program Command

Start

End

Error check

FMR00 = 1?

YES

Write the command code xx77h to the highest-order

even address of block

Write xxD0h to the same highest-order

even address of block

Write command code and data to the same even address.

M32C/8B Datasheet(PDF) 331 Page - Renesas Technology Corp