
CHAPTER 14 PORT FUNCTION
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(b) Pull-up resistor option register 1 (PU1)
PU1 can be read/written in 1-bit or 8-bit units.
Figure 14-8. Pull-up Resistor Option Register 1 (PU1)
After reset:
00H
R/W
Address: FFFFF082H
7
6
5
4
3
2
1
0
PU1
0
0
PU15
PU14
PU13
PU12
PU11
PU10
PU1n
Control of On-Chip Pull-Up Resistor Connection (n = 0 to 5)
0
Do not connect
1
Connect
(c) Port 1 function register (PF1)
PF1 can be read/written in 1-bit or 8-bit units.
Figure 14-9. Port 1 Function Register (PF1)
After reset:
00H
R/W
Address: FFFFF0A2H
7
6
5
4
3
2
1
0
PF1
0
0
PF15
PF14
0
Note
PF12
PF11
PF10
PF1n
Control of Normal Output/N-ch Open-Drain Output (n = 0 to 2, 4, 5)
0
Normal output
1
N-ch open-drain output
Note
Bit 3 is fixed as a normal output.