CHAPTER 5 PORT FUNCTIONS
Preliminary User’s Manual U17260EJ3V1UD
128
(3) Pull-up resistor option registers (PU0, PU1, PU3 to PU5, PU7, PU12, and PU14)
These registers specify whether the on-chip pull-up resistors of P00 to P06, P10 to P17, P30 to P33, P40 to P43,
P50 to P53, P70 to P77, P120, or P140 and P141 are to be used or not. On-chip pull-up resistors can be used in
1-bit units only for the bits set to input mode of the pins to which the use of an on-chip pull-up resistor has been
specified in PU0, PU1, PU3 to PU5, PU7, PU12, and PU14. On-chip pull-up resistors cannot be connected to
bits set to output mode and bits used as alternate-function output pins, regardless of the settings of PU0, PU1,
PU3 to PU5, PU7, PU12, and PU14.
These registers can be set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation sets these registers to 00H.
Figure 5-28. Format of Pull-up Resistor Option Register
7
0
Symbol
PU0
6
PU06
5
PU05
4
PU04
3
PU03
2
PU02
1
PU01
0
PU00
Address
FF30H
After reset
00H
R/W
R/W
PU17
PU1
PU16
PU15
PU14
PU13
PU12
PU11
PU10
FF31H
00H
R/W
0
PU3
0
0
0
PU33
PU32
PU31
PU30
FF33H
00H
R/W
PU4
PU43
PU42
PU41
PU40
FF34H
00H
R/W