Mitsubishi microcomputers
M16C / 61 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Bus Settings
Table 1.10.2. Pin functions for each processor mode
Single-chip
Memory
expansion mode
Processor mode
Memory expansion mode/microprocessor modes
mode
“01”, “10”
“00”
“11” (Note 1)
multiplexed
bus for the
entire
Multiplexed bus
space select bit
Either CS1 or CS2 is for
multiplexed bus and others
are for separate bus
(separate bus)
space
8 bits
“H”
Data bus width
BYTE pin level
16 bits
“L”
8 bits
“H”
16 bits
“L”
8 bit
“H”
P0
0
to P0
7
I/O port
Data bus
Data bus
Data bus
Data bus
I/O port
P1
0
to P1
7
I/O port
I/O port
I/O port
I/O port
I/O port
I/O port
I/O port
Data bus
I/O port
Data bus
I/O port
P2
0
Address bus
/data bus(Note 2)
Address bus
Address bus
Address bus
Address bus
Address bus
/O port
Address bus
Address bus
Address bus
Address bus
I/O port
Address bus
/data bus
P2
1
0
to P2
7
Address bus
/data bus(Note 2) /data bus(Note 2)
Address bus
Address bus
/data bus
P3
Address bus
/data bus(Note 2)
Address bus
Address bus
I/O port
A8/D7
P3
1
to P3
to P4
7
Address bus
I/O port
I/O port
I/O port
P4
Port P4
0
3
0
to P43
function select bit = 1
P4
Port P4
0
to P4
3
I/O port
Address bus
Address bus
Address bus
Address bus
I/O port
0
to P43
function select bit = 0
CS (chip select) or programmable I/O port
(For details, refer to “Bus control”)
P4
P5
P5
P5
4
0
4
5
to P4
7
I/O port
I/O port
I/O port
I/O port
I/O port
I/O port
Outputs RD, WRL, WRH, and BCLK or RD, BHE, WR, and BCLK
(For details, refer to “Bus control”)
to P5
3
HLDA
HOLD
ALE
HLDA
HOLD
ALE
HLDA
HOLD
ALE
HLDA
HOLD
ALE
HLDA
HOLD
ALE
P5
6
7
P5
RDY
RDY
RDY
RDY
RDY
Note 1: If the entire space is of multiplexed bus in memory expansion mode, choose an 8-bit width.
The processor operates using the separate bus after reset is revoked, so the entire space multiplexed bus cannot be
chosen in microprocessor mode.
The higher-order address becomes a port if the entire space multiplexed bus is chosen, so only 256 bytes can be used
in each chip select.
Note 2: Address bus when in separate bus mode.
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MITSUBISHI [ Mitsubishi Group ]
