M16C1N Datasheet, PDF (202/238 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/10 SERIES

M16C/1N Group
19. Flash Memory Version
(5) Block erase
Write 'xx2016' in the first bus cycle and write 'xxD016' to the uppermost address of a block (even
address, however) in the second bus cycle, and an auto erase operation (erase and verify) will start.
Check the FMR0 register's FMR00 bit to see if auto erasing has finished.
The FMR00 bit is "0" during auto erasing and set to "1" when auto erasing is completed.
In EW0 mode, when using the erasure suspend feature, confirm the FMR4 register's FMR46 bit
whether it has shifted to erasure suspend.
The FMR46 bit is "0" during auto erasing and is set to "1" when auto erasing is suspended (shift to
erasure suspend).
Check the FMR0 register's FMR07 bit after auto erasing has finished, and the result of auto erasing
can be known (refer to 19.5.6 Full Status Check).
Also, block 0 and 1 do not accept the block erase command while the FMR0 register's FMR02 bit is set
to "0" (Inhibit rewriting.)
Figure 19.10 shows an example of a block erase flowchart when not using the erasure suspend
feature and Figure 19.11 shows an example of a block erase flowchart when using the erasure sus-
pend feature.
In EW1 mode, do not execute this command on any address at which the rewrite control program is located.
In EW0 mode, the microcomputer goes to read status register mode at the same time auto erasing
starts, making it possible to read the status register. The status register bit 7 (SR7) is cleared to "0" at
the same time auto erasing starts, and set back to "1" when auto erasing finishes. In this case, the
microcomputer remains in read status register mode until the read array command is written next. In
addition, when the erase error occurred, repeat the operation executing the clear status register com-
mand and then the block erase command in succession at least 3 times until the error is eliminated.
Start
Write the command code ’xx2016’
(Note 1)
Write ’xxD016’ to the uppermost
block address (Note 1)
NO
FMR00=1?
YES
Full status check (Note 2, 3)
Block erase completed
Note 1: Write the command code and data at even number.
Note 2: See Figure 19.12 Full status check flowchart, handling each error generated.
Note 3: When the erase error occurred, repeat the operation executing the clear status register command
and then the block erase command in succession at least 3 times until the error is eliminated.
Figure 19.10 Block erase flowchart (when not using the erasure suspend feature)
Rev.1.00 Oct 20, 2004 page 190 of 222
REJ09B0007-0100Z