R8CSLASH20 datasheet(411/501 Pages) RENESAS

411 / 501 page

R8C/20 Group, R8C/21 Group

19. Flash Memory

Rev.2.00 Aug 27, 2008

Page 395 of 458

REJ09B0250-0200

19.4.3.5

Block Erase

If writing 20h in the first bus cycle and D0h to the given address of a block in the second bus cycle, and an auto

erase operation (erase and verify) will start.

The FMR00 bit in the FMR0 register can determine whether auto erasing has completed.

The FMR00 bit is set to 0 during auto erasing and set to 1 when auto erasing completes.

The FMR07 bit in the FMR0 register can determine the result of auto erasing after auto erasing has completed.

(Refer to 19.4.5 Full Status Check)

When the FMR02 bit in the FMR0 register is set to 0 (disable rewriting) or the FMR02 bit is set to 1 (rewrite

enables) and the FMR15 bit in the FMR1 register is set to 1 (disable rewriting), the block erase command on

block 0 is not acknowledged. When the FMR16 bit is set to 1 (disable rewriting), the block erase command on

block 1 is not acknowledged.

Do not use the block erase command during program-suspend.

Figure 19.14 shows the Block Erase Command (When Erase-Suspend Function Disabled). Figure 19.15 shows

the Block Erase Command (When Erase-Suspend Function Enabled).

In EW1 mode, do not execute this command on any address at which the rewrite control program is allocated.

In EW0 mode, the MCU enters read status register mode at the same time auto erasing starts and the status

1 when auto erasing completes. In this case, the MCU remains in read status register mode until the read array

command is written next.

Figure 19.14

Block Erase Command (When Erase-Suspend Function Disabled)

Start

Write the command code 20h

Write ‘D0h’ to the given block

address

FMR00 = 1?

Full status check

Block erase completed

Yes

R8C/20 Datasheet(PDF) 411 Page - Renesas Technology Corp