User’s Manual U14826EJ5V0UD
35
CHAPTER 3 PIN FUNCTIONS
3.1 Pin Function List
(1) Port
pins
Pin Name
I/O
Function
After Reset
Alternate Function
P00 to P07
I/O
Port 0
8-bit I/O port
Input/output can be specified in 1-bit units.
Input
KR0 to KR3
P20
TMO/BSFO
P21
I/O Port
2
2-bit I/O port
Input/output can be specified in 1-bit units.
Input
TMI
P40 to P43
Input
Port 4
4-bit input-only port
For mask ROM versions, an on-chip pull-up resistor can be
specified by means of the mask option.
Input
KR10 to KR13
(2) Non-port
pins
Pin Name
I/O
Function
After Reset
Alternate Function
TMI
Input
8-bit timer (TM40) input Input
P21
TMO
Output
8-bit timer (TM40) output
Input
P20/BSFO
BSFO
Output
Bit sequential buffer (BSF10) output
Input
P20/TMO
KR10 to KR13
Input
Key return input
Input
P40 to P43
X1
Note 1
Input
−
−
X2
Note 1
−
Connecting ceramic/crystal resonator for system clock
oscillation
−
−
CL1
Note 2
Input
−
−
CL2
Note 2
−
Connecting resistor (R) and capacitor (C) for system clock
oscillation
−
−
RESET
Input
System reset input
Input
−
V
DD
−
Positive supply voltage
−
−
V
SS
−
Ground potential
−
−
IC
−
Internally connected. Connect directly to V
SS
.
−
−
V
PP
−
This pin is used to set the EEPROM programming mode and
applies a high voltage when a program is written or verified.
−
−
Notes 1.
µ
PD789860 Subseries only
2.
µ
PD789861 Subseries only