UPD78F9234MC-5A4-A Datasheet, PDF (72/419 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 4 PORT FUNCTIONS
(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
PU0
0
0
0
4
3
2
1
0
0
PU03
PU02
PU01
PU00
Address: FF32H After reset: 00H R/W
Symbol
7
6
5
PU2
0
0
0
4
3
2
1
0
0
PU23
PU22
PU21
PU20
Address: FF33H After reset: 00H R/W
Symbol
7
6
5
PU3
0
0
0
4
3
2
1
0
0
PU33
P32
PU31
PU30
Address: FF34H After reset: 00H R/W
Symbol
7
6
5
PU4
PU47
PU46
PU45
4
PU44
3
PU43
2
PU42
1
PU41
0
PU40
Address: FF3CH After reset: 00H R/W
Symbol
7
6
5
PU12
0
0
0
4
3
2
0
PU123
0
1
0
0
PU120
PUmn
0
1
Selection of connection of on-chip pull-up resistor of Pmn (m = 0, 2, 3, 4, or 12; n = 0 to 7)
Does not connect on-chip pull-up resistor
Connects on-chip pull-up resistor
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User’s Manual U17446EJ5V0UD