M16C6K9 Datasheet, PDF (261/292 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

M16C/6K9 Group
CPU Reprogram Mode
CPU reprogram mode
In CPU reprogram mode, the on-chip flash memory can be operated on (read, program or erase) under the
control of CPU.
In CPU reprogram mode, only the user ROM area shown in Fig.AB-1 can be reprogrammed. The boot ROM
area cannot be reprogrammed. Make sure the program and block erase commands are issued only for each
block of the user ROM area.
The control program for CPU reprogram mode can be stored in either user ROM or boot ROM area. In CPU
reprogram mode, because the flash memory cannot be read form CPU, the control program must be transferred
to the RAM area before execution.
Microcomputer mode and Boot mode
The control program for CPU reprogram mode must be written into the user ROM or boot ROM area in
parallel I/O mode beforehand. (If the control program is written into the boot ROM area, the standard serial I/
O mode becomes disable.)
See Fig.AB-1 for details about the boot ROM area.
Normal microcomputer mode is entered when reset with pulling “L” of M0. In this case, the CPU starts
operating the control program in user ROM area.
If the microcomputer is reset with M0 being “H” and M1 being “L”, the CPU starts operating the control
program in boot ROM area. This mode is called as “boot” mode.
Block address
Block address refers to the maximum even address of each block. The address is used in block erase
command.
Rev.1.00 Jun 06, 2003 page 261 of 290