M16C6K7 Datasheet, PDF (258/285 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Rev.1.0
CPU Reprogram Mode
Mitsubishi microcomputers
M16C / 6K7 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Program located in ROM
Start
Single-chip mode or boot mode
Set processor mode register (Note 1)
Transfer CPU reprogram mode
control program to RAM area
Jump to the program that is transferred to RAM
(the operation hereafter is on RAM)
*1
Program located in RAM
*1
(Only for boot mode)
Set user ROM area select bit to "1"
Set CPU reprogram mode select bit="1"
(write "0" and then write "1") (Note 2)
Operate with S/W commands to erase
and program.
Reset with read array command or the
setting of the flash memory reset bit
(write "1" and then write "0") (Note 3)
Write "0" to CPU reprogram mode select bit.
(Only for boot mode)
Write user ROM area select bit to "0". (Note 4)
End
Note 1: Set the main clock frequency as shown below using the main clock divide ratio select bits (bit 6 at
address 000616 and bit 6 and 7 at address 000716):
Not exceeding 8 MHz if wait bit (bit 7 of address 000516) = "0". (No wait for internal accessing)
Note 2: For writing "1" to the bit, it is necessary to write "0" and "1" in succession. Otherwise the bit will not be
"1". Please do not enter interrupt and DAM.
Note 3: Be sure to execute a read command or to set flash memory reset bit before exiting the CPU reprogram
mode after completing erasing or programming operation.
Note 4: The bit can remain "1" too. If it is "1", user ROM area will be accessed.
Fig.BB-2 CPU reprogram mode set/reset flowchart
257