M16C6K9 Datasheet, PDF (264/292 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6K9 Group
CPU Reprogram Mode
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):
(1) Not exceeding 8 MHz if wait bit (bit 7 of address 000516) = "0". (No wait for internal accessing)
(2) Not exceeding 16 MHz if wait bit (bit 7 of address 000516) = "1". (1 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. The write to the bit should be executed other than the flash
memory area and the NMI pin should be in "H" state.
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
Rev.1.00 Jun 06, 2003 page 264 of 290