Datasheet

78K0/Kx2-L CHAPTER 4 PORT FUNCTIONS
R01UH0028EJ0400 Rev.4.00 177
Sep 27, 2010
(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 of 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, 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 (sets only PU12 to 20H).
Figure 4-40. Format of Pull-up Resistor Option Register (78K0/KY2-L)
7
0
Symbol
PU0
6
0
5
0
4
0
3
0
2
0
1
PU01
0
PU00
Address
FF30H
After reset
00H
R/W
R/W
0
PU3
0 0 0 0 0 0 PU30
FF33H 00H R/W
0
PU6
0 0 0 0 0 PU61 PU60
FF36H 00H R/W
0
PU12
0 PU125 0 0 0 0 0
FF3CH 20H R/W
PUmn
Pmn pin on-chip pull-up resistor selection
(m = 0, 3, 6, 12; n = 0, 1, 5)
0 On-chip pull-up resistor not connected
1 On-chip pull-up resistor connected
Figure 4-41. Format of Pull-up Resistor Option Register (78K0/KA2-L (20-pin products))
7
0
Symbol
PU0
6
0
5
0
4
0
3
0
2
0
1
PU01
0
PU00
Address
FF30H
After reset
00H
R/W
R/W
0
PU3
0 0 0 0 PU32 PU31 PU30
FF33H 00H R/W
0
PU6
0 0 0 0 0 PU61 PU60
FF36H 00H R/W
0
PU12
0 PU125 0 0 0 0 0
FF3CH 20H R/W
PUmn
Pmn pin on-chip pull-up resistor selection
(m = 0, 3, 6, 12; n = 0 to 2, 5)
0 On-chip pull-up resistor not connected
1 On-chip pull-up resistor connected