CHAPTER 4 PORT FUNCTIONS
User’s Manual U16898EJ3V0UD
49
Table 4-1. Port Functions
Pin Name
I/O
Function
After Reset
Alternate-
Function Pin
P20 to P23
I/O
Port 2.
4-bit I/O port.
Can be set to input or output mode in 1-bit units.
On-chip pull-up resistor can be connected by setting software.
Input
ANI0 to ANI3
P30
TI000/INTP0
P31
I/O
Can be set to input or output mode in 1-
bit units.
On-chip pull-up resistor can be
connected by setting software.
Input
TI010/TO00/
INTP2
P34
Note
Input
Port 3
Input only
Input
RESET
Note
P40
−
P41
INTP3
P42
TOH1
P43
TxD6/INTP1
P44
RxD6
P45
I/O Port
4.
6-bit I/O port.
Can be set to input or output mode in 1-bit units.
On-chip pull-up resistor can be connected setting software.
Input
−
P121
Note
X1
Note
P122
Note
X2
Note
P123
I/O Port
12.
3-bit I/O port.
Can be set to input or output mode in 1-bit units.
On-chip pull-up resistor can be connected only to P123 by
setting software.
Input
−
P130 Output
Port
13.
1-bit output-only port.
Output
−
Note
For the setting method for pin functions, see
CHAPTER 17 OPTION BYTE
.
Caution The P121/X1 and P122/X2 pins are pulled down during reset.
Remarks 1.
P121 and P122 can be allocated when the high-speed internal oscillation is selected as the system
clock.
2.
P122 can be allocated when an external clock is selected as the system clock.
4.2 Port
Configuration
Ports consist of the following hardware units.
Table 4-2. Configuration of Ports
Item
Configuration
Control registers
Port mode registers (PM2, PM3, PM4, PM12)
Port registers (P2, P3, P4, P12, P13)
Port mode control register 2 (PMC2)
Pull-up resistor option registers (PU2, PU3, PU4, PU12)
Ports
Total: 17 (CMOS I/O: 15, CMOS input: 1, CMOS output: 1)
Pull-up resistor
Total: 13