M16C1N Datasheet, PDF (195/238 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/10 SERIES

M16C/1N Group
19. Flash Memory Version
Figure 19.6 and 19.7 show the setting and resetting of EW0 mode and EW1 mode, respectively. Figure
19.8 shows the processing before and after low power dissipation mode.
EW0 mode operation procedure
Single-chip mode
Set CM0, CM1, and PM1 registers (Note 1)
Transfer a CPU rewrite mode based rewrite control
program to any area other than the flash memory
Jump to the rewrite control program which has been
transferred to any area other than the flash memory
(The subsequent processing is executed by the
rewrite control program in any area other than the
flash memory)
Rewrite control program
For only boot mode
Set the FMR05 bit to "1"
(User ROM area access)
Set the FMR01 bit by writing "0" and then "1"
(CPU rewrite mode enabled) (Note 2)
Execute software commands
Execute the read array command (Note 3)
Write "0" to the FMR01 bit
(CPU rewrite mode disabled)
For only boot mode
Write "0" to the FMR05 bit
(Boot ROM area accessed) (Note 4)
Jump to a specified address in the flash memory
Note 1: Select 10 MHz or less for CPU clock using the CM0 register’s CM06 bit and CM1 register’s CM17 to 6 bits.
Also, set the PM1 register’s PM17 bit to "1" (with wait state).
Note 2: To set the FMR01 bit to "1", write "0" and then "1" in succession. Make sure no interrupts will occur before
writing "1" after writing "0".
Write to the FMR01 bit by a program in a memory area other than the flash memory.
Note 3: Disables the CPU rewrite mode after executing the read array command.
Note 4: User ROM area is accessed when the FMR05 bit is set to "1".
Figure 19.6 Setting and resetting of EW0 mode
Rev.1.00 Oct 20, 2004 page 183 of 222
REJ09B0007-0100Z