Datasheet

User’s Manual U18172EJ3V0UD
54
CHAPTER 4 PORT FUNCTIONS
4.1 Functions of Ports
The 78K0S/KU1+ has the ports shown in Figure 4-1, which can be used for various control operations. Table 4-1
shows the functions of each port.
In addition to digital I/O port functions, each of these ports has an alternate function. For details, refer to
CHAPTER 2 PIN FUNCTIONS.
Figure 4-1. Port Functions
P43
Port 4
P40
P20
Port 2
P23
P32
Port 3
P34
Table 4-1. Port Functions (
μ PD78F920x)
Pin Name I/O Function After Reset Alternate-
Function Pin
P20 ANI0/TI000/TOH1
P21 ANI1/TI010/TO00/
INTP0
P22
Note 1
X2/ANI2
Note 1
P23
Note 1
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
X1/ANI3
Note 1
P32 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 INTP1
P34
Note 1
Input
Port 3
Input only Input
RESET
Note 1
P40 and P43
Note 2
I/O Port 4.
2-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
−
Notes 1. For the setting method for pin functions, see CHAPTER 15 OPTION BYTE.
2. At program initialization, set PM41, PM42, and PM44 to PM47 to "0".
Caution The P22/X2/ANI2 and P23/X1/ANI3 pins are pulled down during reset.
Remarks 1. P22 and P23 can be allocated when the high-speed internal oscillation is selected as the system clock.
2. P22 can be allocated when an external clock input is selected as the system clock.