
CHAPTER 2 PIN FUNCTIONS
User’s Manual U19780EJ2V0UD
37
2.2.4 P31 to P35 (port 3)
P31 to P35 function as an I/O port. These pins also function as pins for external interrupt request input, serial
interface data I/O, clock I/O, and timer I/O.
78K0/KB2-A 78K0/KC2-A
P31/INTP5/OCD1A (/SCK10)
P32/INTP4/OCD1B (/SI10)
−
P33/TI51/TO51/INTP3
−
P34/TI50/TO50/INTP2
P35/SO10/INTP1
Remark
The functions of pins whose names are in parentheses can be used by setting bit 2 (ISC2) of
the input switch control register (ISC) to 1.
The following operation modes can be specified in 1-bit units.
(1) Port
mode
P31 to P35 function as an I/O port. P31 to P35 can be set to input or output port in 1-bit units using port mode
register 3 (PM3). Use of an on-chip pull-up resistor can be specified by pull-up resistor option register 3 (PU3).
(2) Control
mode
P31 to P35 function as external interrupt request input, serial interface data I/O, clock I/O, and timer I/O.
(a) INTP1 to INTP5
These are the external interrupt request input pins for which the valid edge (rising edge, falling edge, or both
rising and falling edges) can be specified.
(b) SI10
This is a serial data input pin of serial interface CSI10.
(c) SCK10
This is a serial clock I/O pin of serial interface CSI10.
(d) SO10
This is a serial data output pin of serial interface CSI10.
(e) TI50,
TI51
These are the pins for inputting an external count clock to 8-bit timer/event counters 50 and 51.
(f) TO50,
TO51
These are the timer output pins of 8-it timer/event counters 50 and 51.