Rev. 1.0, 02/00, page 195 of 1141
Bits 7 to 0
P17 to P10 Pin Switching (PCR17 toPCR10)
Bit n
PCR1n
Description
0
The P1n pin functions as an input pin
(Initial value)
1
The P1n pin functions as an output pin
(n = 7 to 0)
Port Data Register 1 (PDR1)
0
0
1
0
R/W
2
0
R/W
3
0
4
0
R/W
0
R/W
5
0
7
0
R/W
R/W
R/W
R/W
6
PDR14
PDR13
PDR12
PDR11
PDR10
PDR17
PDR16
PDR15
Bit :
Initial value :
R/W :
Port data register 1 (PDR1) stores the data for the pins P17 to P10 of port 1. When PCR1 is 1
(output), the PDR1 values are directly read if port 1 is read. Accordingly, the pin states are not
affected. When PCR1 is 0 (input), the pin states are read if port 1 is read.
PDR1 is an 8-bit read/ write enable register. When reset, PDR1 is initialized to H'00.
MOS Pull-Up Select Register 1 (PUR1)
0
0
1
0
R/W
2
0
R/W
3
0
4
0
R/W
0
R/W
5
0
7
0
R/W
R/W
R/W
R/W
6
PUR14
PUR13
PUR12
PUR11
PUR10
PUR17
PUR16
PUR15
Bit :
Initial value :
R/W :
MOS pull-up selector register 1 (PUR1) controls the on and off of the MOS pull-up transistor of
port 1. Only the pin whose corresponding bit of PCR1 was set to 0 (input) becomes valid. When
the corresponding bit of PCR1 is set to 1 (output), the corresponding bit of PUR1 becomes invalid
and the MOS pull-up transistor is turned off.
PUR1 is an 8-bit read/ write enable register. When reset, PUR1 is initialized to H'00.
Bits 7 to 0
P17 to P10 MOS Pull-Up Control (PCR17 to PCR10)
Bit n
PUR1n
Description
0
The P1n pin has no MOS pull-up transistor
(Initial value)
1
The P1n pin has a MOS pull-up pin
(n = 7 to 0)