M306V2 Mitsubishi, M306V2 Datasheet - Page 23

• Manufacturer Part Number: M306V2
• Description: SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER and ON-SCREEN DISPLAY CONTROLLER
• Manufacturer: Mitsubishi

Rev. 1.0
2.4 Processor Mode
2.4.1 Types of Processor Mode
2.4.2 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.
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.
(1) Single-chip mode
(2) Memory expansion mode
(3) Microprocessor mode
(1) Applying V
(2) Applying V
In single-chip mode, only internal memory space (SFR, OSD RAM, 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, OSD RAM, 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 “2.4.3 Bus
Settings” for details.)
In microprocessor mode, the SFR, OSD RAM, 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 “2.4.3 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.
Figures 2.4.1 and 2.4.2 show the processor mode register 0 and 1.
Figure 2.4.3 shows the memory maps applicable for each of the modes.
16
). Do not set the processor mode bits to “10
SS
CC
to CNV
to CNV
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER
SS
SS
2
” to the processor mode is selected bits.
pin
pin
SS
pin, changing the processor mode bits selects the mode. Therefore,
SS
pin and the processor mode bits (bits 1 and 0 at address
2
”.
and ON-SCREEN DISPLAY CONTROLLER
MITSUBISHI MICROCOMPUTERS
M306V2ME-XXXFP
M306V2EEFP
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