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CHAPTER 4 PORT FUNCTIONS
User’s Manual U17446EJ3V1UD
67
(4) Pull-up resistor option registers (PU0, PU2, PU3, PU4, and PU12)
These registers are used to specify whether an on-chip pull-up resistor is connected to P00 to P03, P20 to
P23, P30 to P33, P40 to P47, P120, and P123. By setting PU0, PU2, PU3, PU4, or PU12, an on-chip pull-up
resistor can be connected to the port pin corresponding to the bit of PU0, PU2, PU3, PU4, or PU12.
PU0, PU2, PU3, PU4, and PU12 are set by using a 1-bit or 8-bit memory manipulation instruction.
Generation of reset signal set these registers to 00H.
Figure 4-18. Format of Pull-up Resistor Option Register
Address: FF30H After reset: 00H R/W
Symbol
7 6 5 4 3 2 1 0
PU0
0 0 0 0
PU03
PU02
PU01
PU00
Address: FF32H After reset: 00H R/W
Symbol
7 6 5 4 3 2 1 0
PU2
0 0 0 0
PU23
PU22
PU21
PU20
Address: FF33H After reset: 00H R/W
Symbol
7 6 5 4 3 2 1 0
PU3
0 0 0 0
PU33
P32
PU31
PU30
Address: FF34H After reset: 00H R/W
Symbol
7 6 5 4 3 2 1 0
PU4
PU47 PU46 PU45 PU44 PU43 PU42 PU41 PU40
Address: FF3CH After reset: 00H R/W
Symbol
7 6 5 4 3 2 1 0
PU12
0 0 0 0
PU123
0 0
PU120
PUmn
Selection of connection of on-chip pull-up resistor of Pmn (m = 0, 2, 3, 4, or 12; n = 0 to 7)
0
Does not connect on-chip pull-up resistor
1
Connects on-chip pull-up resistor
Содержание 78K0S/KB1+
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