HD64F3642AHV Datasheet, PDF (203/551 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 8 I/O Ports
Upon reset, PDR3 is initialized to H'00.
Port Control Register 3 (PCR3)
Bit
Initial value
Read/Write
7
6
5
4
3
2
1
0





PCR32 PCR31 PCR30
0
0
0
0
0
0
0
0





W
W
W
PCR3 is an 8-bit register for controlling whether each of the port 3 pins P3₂ to P3₀ 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, which is always read as all 1s.
Port Pull-Up Control Register 3 (PUCR3)
Bit
Initial value
Read/Write
7
6
5
4
3
2
1
0





PUCR32 PUCR31 PUCR30
0^*
0^*
0^*
0^*
0^*
0
0
0





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 P3₂ 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.
Port Mode Register 3 (PMR3)
Bit
Initial value
Read/Write
7
6
5
4
3
2
1
0





SO1
SI1
SCK1
0
0
0
0
0
0
0
0





R/W
R/W
R/W
Rev. 6.00 Sep 12, 2006 page 181 of 526
REJ09B0326-0600