M32CSLASH8B datasheet(333/406 Pages) RENESAS

333 / 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 316 of 385

(8) Protect Bit Program Command

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

By writing the command code xx67h in the first bus cycle and xxD0h to the address of the protect bit in the

second bus cycle, the protect bit of the specified block becomes 0. The address specified in the first bus cycle

must be the same address of the protect bit specified in the second bus cycle.

Figure 23.13 shows a flow chart of protect bit program command. Execute the read protect bit status command

to read protect bit status (protect bit data).

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

completed or not.

Refer to 23.3.2 ROM Code Protect Function for addresses of the protect bits, information on protect bit

functions, and how to set it to 1 (unprotected).

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 23.13

Protect Bit Program Command

Start

End

Error check

FMR00 = 1?

YES

Write the command code xx67h to the address of the

protect bit

Write xxD0h to the address of the protect bit

M32C/8B Datasheet(PDF) 333 Page - Renesas Technology Corp