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RL78/G1P
CHAPTER 4 PORT FUNCTIONS
R01UH0895EJ0100 Rev.1.00
87
Nov 29, 2019
4.3.3 Pull-up resistor option registers (PUxx)
These registers specify whether the on-chip pull-up resistors 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 (PMmn = 1) for the pins to which the use of an on-chip pull-up resistor
has been specified in these registers. On-chip pull-up resistors cannot be connected to bits set to output mode and bits
used as alternate-function output pins and analog setting (PMC = 1), regardless of the settings of these registers.
These registers can be set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation clears these registers to 00H (Only PU4 is set to 01H).
Figure 4-18. Format of Pull-up Resistor Option Register
Symbol
7 6 5 4 3 2 1 0
Address
After
reset
R/W
PU1 PU17
Note
PU16 PU15 PU14
Note
PU13 PU12 PU11
Note
PU10 F0031H
00H
R/W
PU3 0 0
PU35
Note
PU34
Note
PU33 PU32 PU31 PU30 F0033H
00H
R/W
PU4
0 0 0 0 0 0 0
PU40
F0034H
01H
R/W
PUmn
Pmn pin on-chip pull-up resistor selection
(m = 0, 1, 4; n = 0 to 7)
0
On-chip pull-up resistor not connected
1
On-chip pull-up resistor connected
Note
These are not provided in 24-pin products.