Chapter 4 Port Functions; Functions Of Ports - NEC 78K0S/KU1+ User Manual

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.
CHAPTER 2 PIN FUNCTIONS.
Pin Name I/O
P20 I/O
P21
Note 1
P22
Note 1
P23
P32 I/O
Note 1
P34 Input
Note 2
P40 and P43
I/O
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.

CHAPTER 4 PORT FUNCTIONS

Figure 4-1. Port Functions
P40
Port 4
P43
Table 4-1. Port Functions
Function
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.
Port 3 Can be set to input or output mode in 1-
bit units.
On-chip pull-up resistor can be
connected by setting software.
Input only
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.
User's Manual U18172EJ2V0UD
P20
Port 2
P23
P32
Port 3
P34
After Reset
Input
Input
Input
Input
For details, refer to
Alternate-
Function Pin
ANI0/TI000/TOH1
ANI1/TI010/TO00/
INTP0
Note 1
X2/ANI2
Note 1
X1/ANI3
INTP1
Note 1
RESET
−
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