Renesas M16C FAMILY Hardware Manual page 163

Under development
Preliminary specification
Specifications in this manual are tentative and subject to change.
R8C/11 Group
Figure 17.3 shows the FMR0 and FMR1 registers. Figure 17.4 shows the FMR4 register.
• FMR00 Bit
This bit indicates the operating status of the flash memory. The bit is "0" during programming, eras-
ing, or erase-suspend mode; otherwise, the bit is "1".
• FMR01 Bit
The microcomputer is made ready to accept commands by setting the FMR01 bit to "1" (CPU rewrite
mode).
• FMR02 Bit
The Block1 and Block0 do not accept the Program and Block Erase commands if the FMR02 bit is
set to "0" (rewrite disabled).
• FMSTP Bit
This bit is provided for initializing the flash memory control circuits, as well as for reducing the amount
of current consumed in the flash memory. The flash memory is disabled against access by setting
the FMSTP bit to "1". Therefore, the FMSTP bit must be written to by a program in other than the
flash memory.
In the following cases, set the FMSTP bit to "1":
• When flash memory access resulted in an error while erasing or programming in EW0 mode
(FMR00 bit not reset to "1" (ready))
• When entering ring oscillator mode (main clock stop)
Figure 17.6 shows a flow chart to be followed before and after entering ring oscillator mode (main
clock stop).
Note that when going to stop or wait mode while the CPU rewrite mode is disabled, the FMR0
register does not need to be set because the power for the flash memory is automatically turned off
and is turned back on again after returning from stop or wait mode.
• FMR06 Bit
This is a read-only bit indicating the status of auto program operation. The bit is set to "1" when a
program error occurs; otherwise, it is cleared to "0". For details, refer to the description of the full
status check.
• FMR07 Bit
This is a read-only bit indicating the status of auto erase operation. The bit is set to "1" when an erase
error occurs; otherwise, it is set to "0". For details, refer to the description of the full status check.
• FMR11 Bit
Setting this bit to "1" (EW1 mode) places the microcomputer in EW1 mode.
• FMR40 bit
The erase-suspend function is enabled by setting the FMR40 bit to "1" (valid).
• FMR41 bit
In EW0 mode, the flash module goes to erase-suspend mode when the FMR41 bit is set to "1". In
EW1 mode, the FMR41 bit is automatically set to "1" (suspend requested) when an enabled interrupt
occurred, and then the flash module goes to erase-suspend mode.
The auto-erase operation restarts when the FMR41 bit is set to "0" (erase restart).
• FMR46 bit
The FMR46 bit is set to "0" during auto-erase execution and set to "1" during erase-suspend mode.
Avoid accessing to the flash memory when this bit is set to "0".
Rev.0.91 2003 Sep 08 page 153 of 184
17.4 CPU Rewrite Mode