Renesas M16C/64C User Manual page 728

M16C/64C Group
30.8.6.8 Block Blank Check Command
The block blank check command is used to check whether or not a specified block is blank (state
after erase).
By writing xx25h in the first bus cycle and xxD0h in the second bus cycle to the highest even address
of a block, the check result is stored in the FMR07 bit in the FMR0 register. Read the FMR07 bit after
the FMR00 bit in the FMR0 register is set to 1 (ready). Do not execute other commands while the
FMR00 bit is 0.
The block blank check command is valid for unlocked blocks.
If the block blank check command is executed on a block whose lock bit is 0 (locked), the FMR07 bit
(SR5) is set to 1 (not blank) regardless of the FMR02 bit state.
Figure 30.23 shows a flowchart of the Block Blank Check Command.
Figure 30.23 Block Blank Check Command
As a result of block blank check, when the block is not blank, execute the clear status register command
before executing other software commands.
The block blank check command is designated for use with a programmer. Use this command where
instantaneous power failures do not occur. When an instantaneous power failure occurs while the block
erase command is executed, execute the block erase command again. The block blank check command
cannot be used to check whether the erase operation is successfully completed or not.
Do not execute the block blank check command during suspend.
R01UH0092EJ0110 Rev.1.10
Jul 31, 2012
Start
Write command code xx25h
to X address
Write xxD0h to BA address
No
FMR00 = 1?
Yes
Yes
FMR06 = 1
FMR07 = 1?
No
Read the FMR07 bit
Block blank check completed
Command
sequence error
30. Flash Memory
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