Table of Contents
Advertisement
Port Data Register 3 (PDR3)
Bit
P3
Initial value
Read/Write
R/W
PDR3 is an 8-bit register that stores data for port 3 pins P3
bits are set to 1, the values stored in PDR3 are read, regardless of the actual pin states. If port 3 is
read while PCR3 bits are cleared to 0, the pin states are read.
Upon reset, PDR3 is initialized to H'00.
Port Control Register 3 (PCR3)
Bit
PCR3
Initial value
Read/Write
W
PCR3 is an 8-bit register for controlling whether each of the port 3 pins P3
input pin or output pin. Setting a PCR3 bit to 1 makes the corresponding pin an output pin, while
clearing the bit to 0 makes the pin an input pin. The settings in PCR3 and in PDR3 are valid only
when the corresponding pin is designated in PMR3 as a general I/O pin.
Upon reset, PCR3 is initialized to H'00.
PCR3 is a write-only register, which is always read as all 1s.
Port Pull-Up Control Register 3 (PUCR3)
Bit
PUCR3
Initial value
Read/Write
R/W
PUCR3 controls whether the MOS pull-up of each of the port 3 pins P3
a PCR3 bit is cleared to 0, setting the corresponding PUCR3 bit to 1 turns on the MOS pull-up for
the corresponding pin, while clearing the bit to 0 turns off the MOS pull-up.
Upon reset, PUCR3 is initialized to H'00.
7
6
5
P3
P3
7
6
0
0
0
R/W
R/W
7
6
5
PCR3
PCR3
7
6
0
0
0
W
W
7
6
5
PUCR3
PUCR3
7
6
0
0
0
R/W
R/W
4
3
P3
P3
5
4
3
0
0
R/W
R/W
to P3
7
4
3
PCR3
PCR3
5
4
0
0
W
W
4
3
PUCR3
PUCR3
4
5
0
0
R/W
R/W
2
1
P3
P3
2
1
0
0
R/W
R/W
. If port 3 is read while PCR3
0
2
1
PCR3
PCR3
3
2
1
0
0
W
W
to P3
functions as an
7
0
2
1
PUCR3
PUCR3
3
1
2
0
0
R/W
R/W
to P3
is on or off. When
7
0
Rev. 6.00, 08/04, page 197 of 628
0
P3
0
0
R/W
0
PCR3
0
0
W
0
PUCR3
0
0
R/W
Advertisement
Table of Contents
