M30622M4 MITSUBISHI [Mitsubishi Electric Semiconductor], M30622M4 Datasheet - Page 236

• Manufacturer Part Number: M30622M4
• Description: SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
• Manufacturer: MITSUBISHI [Mitsubishi Electric Semiconductor]

CPU Rewrite Mode (Flash Memory Version)
236
CPU Rewrite Mode
In CPU rewrite mode, the on-chip flash memory can be operated on (read, program, or erase) under control
of the Central Processing Unit (CPU).
In CPU rewrite mode, only the user ROM area shown in Figure 1.28.1 can be rewritten; the boot ROM area
cannot be rewritten. Make sure the program and block erase commands are issued for only the user ROM
area and each block area.
The control program for CPU rewrite mode can be stored in either user ROM or boot ROM area. In the CPU
rewrite mode, because the flash memory cannot be read from the CPU, the rewrite control program must
be transferred to any area other than the internal flash memory before it can be executed.
Microcomputer Mode and Boot Mode
Block Address
The control program for CPU rewrite 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 unusable.)
See Figure 1.28.1 for details about the boot ROM area.
Normal microcomputer mode is entered when the microcomputer is reset with pulling CNV
this case, the CPU starts operating using the control program in the user ROM area.
When the microcomputer is reset by pulling the P5
CPU starts operating using the control program in the boot ROM area. This mode is called the “boot”
mode. The control program in the boot ROM area can also be used to rewrite the user ROM area.
Block addresses refer to the maximum even address of each block. These addresses are used in the
block erase command, lock bit program command, and read lock status command.
5
pin low, the CNV
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
SS
pin high, and the P5
Mitsubishi microcomputers
M16C / 62 Group
0
SS
pin high, the
pin low. In