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CHAPTER 4 PIN FUNCTIONS (
μ
PD780078Y SUBSERIES)
User’s Manual U14260EJ3V1UD
4.2 Description of Pin Functions
4.2.1 P00 to P03 (Port 0)
P00 to P03 function as a 4-bit I/O port. Besides serving as an I/O port, they also function as external interrupt
inputs and an A/D converter external trigger input.
The following operating modes can be specified in 1-bit units.
(1) Port mode
These pins function as a 4-bit I/O port.
P00 to P03 can be specified as input or output in 1-bit units using port mode register 0 (PM0). On-chip pull-up
resistors can be connected by setting pull-up resistor option register 0 (PU0).
(2) Control mode
In this mode, these pins function as external interrupt request inputs and an A/D converter external trigger input.
(a) INTP0 to INTP3
INTP0 to INTP3 are external interrupt request input pins for which the valid edge can be specified (rising
edge, falling edge, or both rising and falling edges).
(b) ADTRG
A/D converter external trigger input pin.
Caution
When P03 is used as an A/D converter external trigger input, specify the valid edge by
using bits 1 and 2 (EGA00, EGA01) of the A/D converter mode register (ADM0) and set the
interrupt mask flag (PMK3) to 1.
4.2.2 P10 to P17 (Port 1)
P10 to P17 function as an 8-bit input-only port. Besides serving as an input port, they also function as A/D converter
analog inputs.
The following operating modes can be specified in 1-bit units.
(1) Port mode
These pins function as an 8-bit input-only port.
(2) Control mode
These pins function as A/D converter analog input pins (ANI0 to ANI7). When using these pins as analog input
pins, see
(4) ANI0/P10 to ANI7/P17
in
13.6 Cautions for A/D Converter
.
4.2.3 P20 to P25 (Port 2)
P20 to P25 function as a 6-bit I/O port. Besides serving as an I/O port, they function as data I/O and clock I/O for
serial interfaces CSI1 and UART0.
The following operating modes can be specified in 1-bit units.
(1) Port mode
These pins function as a 6-bit I/O port. They can be specified as input or output in 1-bit units using port mode
register 2 (PM2). On-chip pull-up resistors can be connected by setting pull-up resistor option register 2 (PU2).