M16C30P_07 Datasheet, PDF (221/317 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/30 SERIES

M16C/30P Group
19. Flash Memory Version
19.3.3.1 FMR00 Bit
This bit indicates the flash memory operating state. It is set to “0” while the program, block erase, lock bit
program, or read lock bit status command is being executed; otherwise, it is set to “1”.
19.3.3.2 FMR01 Bit
The microcomputer can accept commands when the FMR01 bit is set to “1” (CPU rewrite mode). Set the
FMR05 bit to “1” (user ROM area access) as well if in boot mode.
19.3.3.3 FMR02 Bit
The lock bit is disabled by setting the FMR02 bit to “1” (lock bit disabled). (Refer to 19.3.6 Data Protect
Function.) The lock bit is enabled by setting the FMR02 bit to “0” (lock bit enabled).
The FMR02 bit does not change the lock bit status but disables the lock bit function. If the block erase
command is executed when the FMR02 bit is set to “1”, the lock bit status changes “0” (locked) to “1”
(unlocked) after command execution is completed.
19.3.3.4 FMSTP Bit
The FMSTP bit resets the flash memory control circuits and minimizes power consumption in the flash
memory. Access to the flash memory is disabled when the FMSTP bit is set to “1”. Set the FMSTP bit by
program in a space other than the flash memory.
• Set the FMSTP bit to “1” if one of the followings occurs: A flash memory access error occurs while erasing
or programming in EW0 mode (FMR00 bit does not switch back to “1” (ready)).
• Low-power consumption mode is entered
Use the following procedure to change the FMSTP bit setting.
To stop the flash memory,
(1) Set the FMSTP bit to “1”
(2) Set tps (the wait time to stabilize flash memory circuit)
To restart the flash memory,
(1) Set the FMSTP bit to “0”
(2) Set tps (the wait time to stabilize flash memory circuit)
Figure 19.8 shows a Flow Chart Illustrating How To Start and Stop the Flash Memory Processing Before and
After Low Power Dissipation Mode. Follow the procedure on this flow chart.
When entering stop or wait mode, the flash memory is automatically turned off. When exiting stop or wait
mode, the flash memory is turned back on. The FMR0 register does not need to be set.
19.3.3.5 FMR05 Bit
This bit selects the boot ROM or user ROM area in boot mode. Set to “0” to access (read) the boot ROM area or
to “1” (user ROM access) to access (read, write or erase) the user ROM area.
Rev.1.22 Mar 29, 2007 Page 205 of 291
REJ09B0179-0122