M30622 Mitsubishi, M30622 Datasheet - Page 28

• Manufacturer Part Number: M30622
• Description: SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
• Manufacturer: Mitsubishi

Software Reset
Software Reset
Processor Mode
Writing “1” to bit 3 of the processor mode register 0 (address 0004
microcomputer. A software reset has almost the same effect as a hardware reset. The contents of internal
RAM are preserved.
(1) Types of Processor Mode
(2) Setting Processor Modes
One of three processor modes can be selected: single-chip mode, memory expansion mode, and micro-
processor mode. The functions of some pins, the memory map, and the access space differ according to
the selected processor mode.
But M16C/62T group is not guaranteed to operate in memory expansion and microprocessor modes.
The processor mode is set using the CNV
0004
Regardless of the level of the CNV
never change the processor mode bits when changing the contents of other bits. Also do not attempt to
shift to or from the microprocessor mode within the program stored in the internal ROM area.
Figure 1.9.1 shows the processor mode register 0 and 1.
Figure 1.10.1 shows the memory maps applicable for each of the modes when memory area dose not be
expanded (normal mode).
• Single-chip mode
• Memory expansion mode
• Microprocessor mode
• Applying V
• Applying V
In single-chip mode, only internal memory space (SFR, internal RAM, and internal ROM) can be
accessed. Ports P0 to P10 can be used as programmable I/O ports or as I/O ports for the internal
peripheral functions.
In memory expansion mode, external memory can be accessed in addition to the internal memory
space (SFR, internal RAM, and internal ROM).
In this mode, some of the pins function as the address bus, the data bus, and as control signals. The
number of pins assigned to these functions depends on the bus and register settings. (See “Bus
Settings” for details.)
In microprocessor mode, the SFR, internal RAM, and external memory space can be accessed. The
internal ROM area cannot be accessed.
In this mode, some of the pins function as the address bus, the data bus, and as control signals. The
number of pins assigned to these functions depends on the bus and register settings. (See “Bus
Settings” for details.)
The microcomputer begins operation in single-chip mode after being reset. Memory expansion mode
is selected by writing “01
The microcomputer starts to operate in microprocessor mode after being reset.
16
). Do not set the processor mode bits to “10
SS
CC
to CNV
to CNV
SS
SS
2
pin
pin
” to the processor mode is selected bits.
SS
pin, changing the processor mode bits selects the mode. Therefore,
SS
pin and the processor mode bits (bits 1 and 0 at address
28
2
”.
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
16
) applies a (software) reset to the
Mitsubishi microcomputers
M16C / 62T Group