NEC 78K0S/KA1+ User Manual page 64

(4) Pull-up resistor option registers (PU2, PU3, PU4, PU12)
These registers are used to specify whether an on-chip pull-up resistor is connected to P20 to P23, P30, P31,
P40 to P45, and P123. By setting PU2, PU3, PU4, or PU12, an on-chip pull-up resistor can be connected to
the port pin corresponding to the bit of PU2, PU3, PU4, or PU12.
PU2, PU3, PU4, and PU12 are set by using a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation set these registers to 00H.
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 0
Address: FF3CH After reset: 00H R/W
Symbol 7
PU12 0
PUmn
0 Does not connect on-chip pull-up resistor
1 Connects on-chip pull-up resistor
64
CHAPTER 4 PORT FUNCTIONS
Figure 4-16. Format of Pull-up Resistor Option Register
6 5 4
0 0 0
6 5 4
0 0 0
6 5 4
0 PU45 PU44
6 5 4
0 0 0
Selection of connection of on-chip pull-up resistor of Pmn (m = 2, 3, 4, or 12; n = 0 to 5)
User's Manual U16898EJ3V0UD
3 2
PU23 PU22 PU21
3 2
0 0 PU31
3 2
PU43 PU42 PU41
3 2
PU123 0
1 0
PU20
1 0
PU30
1 0
PU40
1 0
0 0