Renesas F-ZTAT H8 Series, Hardware Manual

Page: 216 / 562

8. I/O Ports
Rev.3.00 Jul. 19, 2007 page 190 of 532
REJ09B0397-0300
Port Data Register 3 (PDR3)
Bit 7 6 5 4 3 2 1 0
P3
7
P3
6
P3
5
P3
4
P3
3
P3
2
P3
1
P3
0
Initial value 0 0 0 0 0 0 0 0
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
PDR3 is an 8-bit register that stores data for port 3 pins P3
7
to P3
0
. If port 3 is read while PCR3
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 7 6 5 4 3 2 1 0
PCR3
7
PCR3
6
PCR3
5
PCR3
4
PCR3
3
PCR3
2
PCR3
1
PCR3
0
Initial value 0 0 0 0 0 0 0 0
Read/Write W W W W W W W W
PCR3 is an 8-bit register for controlling whether each of the port 3 pins P3
7
to P3
0
functions as an
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. All bits are read as 1.
Port Pull-Up Control Register 3 (PUCR3)
Bit 7 6 5 4 3 2 1 0
PUCR3
7
PUCR3
6
PUCR3
5
PUCR3
4
PUCR3
3
PUCR3
2
PUCR3
1
PUCR3
0
Initial value 0 0 0 0 0 0 0 0
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
PUCR3 bits control the on/off state of pin P3
7
–P3
0
MOS pull-ups. When 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.