Programmable I/O Ports
Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
447
(6) I/O functions of built-in peripheral devices
Table 2.15.1 shows relation between ports and I/O functions of built-in peripheral devices.
Port
P6
Internal peripheral device I/O pins
I/O pins for serial I/O communication
I/O pins for serial I/O communication/Timer A I/O pins/Timer B input pin
P71
P80, P81
Timer A I/O pins
P82 to P84
Input pins for external interrupt
P86, P87
Sub-clock oscillation circuit I/O pins
P90 to P92
Timer B input pins
P93, P94
D-A converter output pins
P95, P96
A-D converter extended input pins
P97
A-D trigger input pin
P100 to P103
A-D converter input pins
P104 to P107
A-D converter input pins / key-input interrupt function input pins
Timer A I/O pins
P76 to P77
P15 to P17
Input pins for external interrupt
I/O pins for serial I/O communication/Timer A I/O pin
P70
P72 to P73
I/O pins for serial I/O communication/Timer A I/O pins/Three-phase motor
control output pins
Timer A I/O pins/Three-phase motor control output pins
P74 to P75
Table 2.15.1. Relation between ports and I/O functions of built-in peripheral devices
(7) Examples of working on non-used pins
Table 2.15.2 contains examples of working on non-used pins. There are shown here for mere ex-
amples. In practical use, make suitable changes and perform sufficient evaluation in compliance with
you application.
(a) Single-chip mode
Table 2.15.2. Examples of working on unused pins in single-chip mode
Pin name
Connection
Ports P0 to P10 (excluding P85)
XOUT (Note 2)
NMI
After setting for input mode, connect every pin to VSS or VCC via a
resistor; or after setting for output mode, leave these pins open.
(Note 1, Note 3)
Open
Connect to VCC via a resistor
AVSS, VREF, BYTE
Connect to VSS
If setting these pins in output mode and opening them, ports are in input mode until switched into
output mode by use of software after reset. Thus the voltage levels of the pins become unstable,
and there can be instances in which the power source current increases while the ports are in
input mode.
In view of an instance in which the contents of the direction registers change due to a runaway
generated by noise or other causes, setting the contents of the direction registers periodically by
use of software increases program reliability.
When an external clock is input to the XIN pin.
Output "L" if port P70 and P71 are set to output mode.
Port P70 and P71 are N channel open drain.
Note 1:
Note 2:
Note 3:
AVCC
Connect to VCC