Renesas M16C/60 Series Hardware Manual page 278

Under development
This document is under development and its contents are subject to change.
M16C/6N5 Group
Figure 1.22.4 shows the FMR0 register and FMR1 register.
FMR00 Bit
This bit indicates the operating status of the flash memory. The bit is "0" when the Program, Erase, or
Lock Bit program is running; 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). During boot mode, make sure the FMR05 bit also is "1" (user ROM area access).
FMR02 Bit
The lock bit set for each block can be disabled by setting the FMR02 bit to "1" (lock bit disabled). (Refer to
"Data Protect Function".) The lock bits set are enabled by setting the FMR02 bit to "0".
The FMR02 bit only disables the lock bit function and does not modify the lock bit data (lock bit status
flag). However, if the Erase command is executed while the FMR02 bit is set to "1", the lock bit data
changes state from "0" (locked) to "1" (unlocked) after Erase is completed.
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. Setting the FMSTP bit to "1" makes the internal flash memory
inaccessible. Therefore, make sure the FMSTP bit is modified in other than the flash memory area.
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 low power dissipation mode or ring oscillator low power dissipation mode
Figure 1.22.7 shows a flow chart to be followed before and after entering low power dissipation mode.
Note that when going to stop or wait mode, the FMR0 register does not need to be set because the power
for the internal flash memory is automatically turned off and is turned back on again after returning from
stop or wait mode.
FMR05 Bit
This bit switches between the boot ROM and user ROM areas during boot mode. Set this bit to "0" when
accessing the boot ROM area (for read) or "1" (user ROM access) when accessing the user ROM area
(for read, write, or erase).
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 set to "0". For details, refer to "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 "Full Status Check".
FMR11 Bit
Setting this bit to "1" (EW1 mode) places the microcomputer in EW1 mode.
FMR16 Bit
This is a read-only bit indicating the execution result of the Read Lock Bit Status command.
Figures 1.22.5 and 1.22.6 show the setting and resetting of EW0 mode and EW1 mode, respectively.
Rev.1.00 2003.05.30 page 264
Flash Memory