H83657 Datasheet, PDF (141/453 Pages) Renesas Technology Corp – single-chip microcomputers

3. Port pull-up control register 3 (PUCR3)
Bit
7
6
5
4
3
2
1
0
—
— PUCR3₅ PUCR3₄ PUCR3₃ PUCR3₂ PUCR3₁ PUCR3₀
Initial value
0^*
0^*
0
0
0
0
0
0
Read/Write
—
—
R/W R/W R/W R/W R/W R/W
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 P3₅ to P3₀ is on or off. 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.
Upon reset, PUCR3 is initialized to H'00.
4. Port mode register 3 (PMR3)
Bit
7
6
5
4
3
2
1
0
—
—
—
—
—
SO1
SI1 SCK1
Initial value
0
0
0
0
0
0
0
0
Read/Write
—
—
—
—
—
R/W R/W R/W
PMR3 is an 8-bit read/write register, controlling the selection of pin functions for port 3 pins.
Upon reset, PMR3 is initialized to H'00.
Bits 7 to 3: Reserved bits
Bits 7 to 3 are reserved: they are always read as 0 and cannot be modified.
Bit 2: P3₂/SO₁ pin function switch (SO1)
This bit selects whether pin P3₂/SO₁ is used as P3₂ or as SO₁.
Bit 2
SO1
0
1
Description
Functions as P3₂ I/O pin
Functions as SO₁ output pin
(initial value)
133