HD6433640 HITACHI [Hitachi Semiconductor], HD6433640 Datasheet - Page 191

• Manufacturer Part Number: HD6433640
• Description: H8/3644 Series Hardware Manual
• Manufacturer: HITACHI [Hitachi Semiconductor]

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)
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)
Note: * Bits 7 to 3 are reserved; they are always read as 0 and cannot be modified.
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.
Bit
Initial value
Read/Write
Bit
Initial value
Read/Write
—
—
—
0*
—
7
0
7
—
—
—
0*
—
6
0
6
—
—
—
0*
—
5
0
5
—
—
—
0*
—
4
0
4
2
to P3
—
—
—
0*
—
3
0
3
0
. If port 3 is read while PCR3
PUCR3
PCR3
R/W
2
W
2
0
2
0
to P3
2
2
to P3
2
0
PUCR3
is on or off. When
PCR3
0
R/W
W
functions as an
1
0
1
0
1
1
PUCR3
PCR3
R/W
W
0
0
0
0
183
0
0