UPD17230 Datasheet, PDF (34/92 Pages) NEC – 4-BIT SINGLE-CHIP MICROCONTROLLER FOR SMALL GENERAL-PURPOSE INFRARED REMOTE CONTROL TRANSMITTER

µPD17230, 17231, 17232, 17233, 17234, 17235, 17236
3.9 Selecting I/O Mode of Group I/O
An I/O that is set in the input or output mode in 4-bit units is called a group I/O. P0C and P0D can be used as
group I/O ports. The input and output modes of these ports are selected by using the following register file. If the
mode is changed from input to output, the contents of the port register are output to the respective ports as soon as
the mode has been changed.
3
2
1
P0DGIO
P0CGIO
0
0
Address On reset R/W
0
RF : 37H
CH
R/W
P0CGIO
0
1
I/O mode of P0C0-P0C3
Sets P0C0-P0C3 in input mode.
Sets P0C0-P0C3 in output mode.
P0DGIO
0
1
I/O mode of P0D0-P0D3
Sets P0D0-P0D3 in input mode.
Sets P0D0-P0D3 in output mode.
34
Data Sheet U14360EJ1V0DS00