Renesas F-ZTAT H8 Series, Hardware Manual

Page: 217 / 562

8. I/O Ports
Rev.3.00 Jul. 19, 2007 page 191 of 532
REJ09B0397-0300
Upon reset, PUCR3 is initialized to H'00.
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 should always be cleared to 0.
Bit 2—P3
2
/SO
1
Pin Function Switch (SO1): This bit selects whether pin P3
2
/SO
1
is used as P3
2
or
as SO
1
.
Bit 2: SO1 Description
0 Functions as P3
2
I/O pin (initial value)
1 Functions as SO
1
output pin
Bit 1—P3
1
/SI
1
Pin Function Switch (SI1): This bit selects whether pin P3
1
/SI
1
is used as P3
1
or as
SI
1
.
Bit 1: SI1 Description
0 Functions as P3
1
I/O pin (initial value)
1 Functions as SI
1
input pin
Bit 0—P3
0
/SCK
1
Pin Function Switch (SCK1): This bit selects whether pin P3
0
/SCK
1
is used as
P3
0
or as SCK
1
.
Bit 0: SCK1 Description
0 Functions as P3
0
I/O pin (initial value)
1 Functions as SCK
1
I/O pin