32186 datasheet(184/1032 Pages) RENESAS

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INTERNAL MEMORY

6-42

32185/32186 Group Hardware Manual

Rev.1.10 REJ09B0235-0110 May 15, 07

6.6 Programming Internal Flash Memory

Figure 6.6.14 Read Lock Bit Status (Register Read Mode)

The following describes how to write to the lock bit.

a) To clear the lock bit to "0" (flash protected)

Issue the Lock Bit Program command (H’7777) to the memory block to be protected.

b) To set the lock bit to "1" (flash unprotected)

After setting the FPROT bit in Flash Control Register 2 to "1" (protection by lock bit disabled), use the

Block Erase command (H’2020) to erase the memory block to be unprotected.

The lock bit cannot be set to "1" directly by writing to it.

c) Lock bit status when reset

Because the lock bit is a nonvolatile bit, it remains unaffected when the microcomputer is reset or

powered off.

END

START

Write the Verify command (H'D0D0)

to any address of the block

Write the Read Lock Bit Status

command (H'7171) to any address

of the block to be read

TIME OUT?

YES

Forcibly terminated

YES

Confirm the Lock bit status bit

(Note 1)

FBUSY bit = 1

10 µs

Note 1: Check Flash Control Register 4 (FCNT4) FLOCKST bit.

32186 Datasheet(PDF) 184 Page - Renesas Technology Corp