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CHAPTER 2 PIN FUNCTIONS
User’s Manual U19780EJ2V0UD
38
Caution Process the P31/INTP5/OCD1A (/SCK10) pin as follows, when it is not used when it is
connected to a flash memory programmer or an on-chip debug emulator.
P31/INTP5/OCD1A
(/SCK10)
Flash memory programmer connection
During reset
Connect to V
SS
via a resistor.
On-chip debug
emulator connection
(when it is not used
as an on-chip debug
mode setting pin)
During reset released
Input:
Connect to V
DD
or V
SS
via a
resistor.
Output: Leave
open.
Remark
P31 and P32 can be used as on-chip debug mode setting pins (OCD1A and OCD1B) when the
on-chip debug function is used. For how to connect an on-chip debug emulator (QB-MINI2), see
CHAPTER 26 ON-CHIP DEBUG FUNCTION.
2.2.5 P40 to P42 (port 4)
P40 to P42 function as an I/O port. These pins also function as external interrupt request input, clock output,
real-time counter clock output, and chip select input for serial interface.
78K0/KB2-A 78K0/KC2-A
P40/RTCCL/RTCDIV
P41/RTC1HZ
−
P42/PCL/SSI10/INTP9
The following operation modes can be specified in 1-bit units.
(1) Port
mode
P40 to P42 function as an I/O port. P40 to P42 can be set to input or output port in 1-bit units using port mode
register 4 (PM4). Use of an on-chip pull-up resistor can be specified by pull-up resistor option register 4 (PU4).
(2) Control
mode
P40 to P42 function as external interrupt request input, clock output, real-time counter clock output, and chip
select input for serial interface.
(a) INTP9
There is the external interrupt request input pin for which the valid edge (rising edge, falling edge, or both
rising and falling edges) can be specified.
(b) PCL
This is a clock output pin.
(c) RTCDIV
This is a real-time counter clock (32 kHz divided oscillation) output pin.
(d) RTCCL
This is a real-time counter clock (32 kHz original oscillation) output pin.