Datasheet

CHAPTER 2 PIN FUNCTIONS
User’s Manual U18172EJ3V0UD
23
2.1.2 μ PD78F950x
(1) Port pins
Pin Name I/O Function After Reset Alternate-Function
Pin
P20 TOH1
P21 INTP0
P22
−
P23
Note
I/O Port 2.
4-bit I/O port.
Can be set to input or output mode in 1-bit units.
An on-chip pull-up resistor can be connected by setting
software.
Input port
EXCLK
Note
P32 I/O Can be set to input or output mode in
1-bit units.
Input port INTP1
P34
Note
Input
Port 3
An on-chip pull-up
resistor can be
connected by setting
software.
Input only Input port
RESET
Note
P40, P43 I/O Port 4.
2-bit I/O port.
Can be set to input or output mode in 1-bit units.
An on-chip pull-up resistor can be connected by setting
software.
Input port
−
Note For the setting method for pin functions, see CHAPTER 15 OPTION BYTE.
Caution The P22 and P23/EXCLK pins are pulled down during reset. The P34/RESET pin is pulled up during
reset by the reset pin function/power-on clear circuit.
(2) Non-port pins
Pin Name I/O Function After Reset Alternate-
Function Pin
INTP0 P21
INTP1
Input External interrupt input for which the valid edge (rising edge,
falling edge, or both rising and falling edges) can be specified
Input port
P32
TOH1 Output 8-bit timer H1 output Input port P20
RESET
Note
Input System reset input Input port
P34
Note
EXCLK
Note
Input External clock input for main system clock Input port
P23
Note
VDD
−
Positive power supply
− −
VSS
−
Ground potential
− −
Note For the setting method for pin functions, see CHAPTER 15 OPTION BYTE.
Caution The P22 and P23/EXCLK pins are pulled down during reset. The P34/RESET pin is pulled up during
reset by the reset pin function/power-on clear circuit.
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