CHAPTER 2 PIN FUNCTIONS
CHAPTER 2 PIN FUNCTIONS
2.1 Pin Function List
(1) Port pins
Pin Name
P00 to P04
P10, P11
P20
P21
P22
P23
P24
P25
P26
P30
P31
P32
P33
P50 to P53
P60 to P63
I/O
I/O
I/O
I/O
I/O
I/O
Input
Function
Port 0
5-bit input/output port
Input/output mode can be specified in 1-bit units
When used as an input port, an on-chip pull-up resistor can
be specified by means of pull-up resistor option register 0
(PU0).
Port 1
2-bit input/output port
Input/output mode can be specified in 1-bit units
When used as an input port, an on-chip pull-up resistor can
be specified by means of pull-up resistor option register 0
(PU0).
Port 2
7-bit input/output port
Input/output mode can be specified in 1-bit units
For P20 to P22, P25, and P26, an on-chip pull-up resistor
can be specified by means of pull-up resistor option register
B2 (PUB2).
Only P23 and P24 can be used as N-ch open-drain
input/output port pins.
Port 3
4-bit input/output port
Input/output mode can be specified in 1-bit units
An on-chip pull-up resistor can be specified by means of pull-
up resistor option register B3 (PUB3).
Port 5
4-bit N-ch open-drain input/output port
Input/output mode can be specified in 1-bit units
For a mask ROM version, an on-chip pull-up resistor can be
specified by the mask option.
Port 6
4-bit input-only port
After Reset
Input
Input
Input
Input
Input
Input
Alternate Function
−
−
SCK20/ASCK20
SO20/TxD20
SI20/RxD20
−
−
TI80/SS20
TO80
INTP0/TI81/CPT90
INTP1/TO81
INTP2/TO90
INTP3/TO82/BZO90
−
ANI0 to ANI3
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User’s Manual 2nd edition