NEC 78K0S/KB1+ User Manual page 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.
Address: FF30H After reset: 00H R/W
Symbol 7
PU0 0
Address: FF32H After reset: 00H R/W
Symbol 7
PU2 0
Address: FF33H After reset: 00H R/W
Symbol 7
PU3
0
Address: FF34H After reset: 00H R/W
Symbol 7
PU4 PU47 PU46
Address: FF3CH After reset: 00H R/W
Symbol 7
PU12 0
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
CHAPTER 4 PORT FUNCTIONS
Figure 4-18. Format of Pull-up Resistor Option Register
6 5 4
0 0 0
6 5 4
0 0 0
6 5 4
0 0 0
6 5 4
PU45 PU44
6 5 4
0 0 0
User's Manual U17446EJ3V1UD
3 2
PU03 PU02 PU01
3 2
PU23 PU22 PU21
3 2
PU33 P32 PU31
3 2
PU43 PU42 PU41
3 2
PU123 0
1 0
PU00
1 0
PU20
1 0
PU30
1 0
PU40
1 0
0 PU120
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