R8C/1A Group, R8C/1B Group 18. Flash Memory
Rev.1.30 Dec 08, 2006 Page 264 of 315
REJ09B0252-0130
18.4.3.5 Block Erase
When 20h is written in the first bus cycle and D0h is written to a given address of a block in the second bus
cycle, an auto-erase operation (erase and verify) of the specified block starts.
The FMR00 bit in the FMR0 register can be used to determine whether auto-erasure has completed.
The FMR00 bit is set to 0 during auto-erasure and set to 1 when auto-erasure completes.
The FMR07 bit in the FMR0 register can be used to determine the result of auto-erasure after auto-erasure has
completed. (Refer to 18.4.5 Full Status Check.)
When the FMR02 bit in the FMR0 register is set to 0 (rewriting disabled) or the FMR02 bit is set to 1 (rewriting
enabled) and the FMR15 bit in the FMR1 register is set to 1 (rewriting disabled), the block erase commands
targeting block 0 are not acknowledged. When the FMR16 bit is set to 1 (rewriting disabled), the block erase
commands targeting block 1 are not acknowledged.
Do not use the block erase command during program-suspend.
Figure 18.14 shows the Block Erase Command (When Erase-Suspend Function Disabled). Figure 18.15 shows
the Block Erase Command (When Erase-Suspend Function Enabled).
In EW1 mode, do not execute this command for any address to which a rewrite control program is allocated.
In EW0 mode, the MCU enters read status register mode at the same time auto-erasure starts and the status
register can be read. The status register bit 7 (SR7) is set to 0 at the same time auto-erasure starts and set back to
1 when auto-erasure completes. In this case, the MCU remains in read status register mode until the next read
array command is written.
Figure 18.14 Block Erase Command (When Erase-Suspend Function Disabled)
Start
Write the command code 20h
Write D0h to a given block
address
FMR00 = 1?
Full status check
Block erase completed
No
Yes
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