Section 8 I/O Ports
Rev. 7.00 Mar 10, 2005 page 241 of 652
REJ09B0042-0700
8.12.2 Register Configuration and Descriptions
Table 8.31 shows the registers used by the input/output data inversion function.
Table 8.31 Register Configuration
Name Abbr. R/W Address
Serial port control register SPCR R/W H'FF91
Serial Port Control Register (SPCR)
Bit
Initial value
Read/Write
7

1

6

1

5
SPC32
0
R/W
4


W
3
SCINV3
0
R/W
0


W
2
SCINV2
0
R/W
1


W
SPCR is an 8-bit readable/writable register that performs RXD
32
and TXD
32
pin input/output data
inversion switching.
Bits 7 and 6—Reserved
Bits 7 and 6 are reserved; they are always read as 1 and cannot be modified.
Bit 5—P4
2
/TXD
32
Pin Function Switch (SPC32)
This bit selects whether pin P4
2
/TXD
32
is used as P4
2
or as TXD
32
.
Bit 5
SPC32 Description
0 Functions as P4
2
I/O pin (initial value)
1 Functions as TXD
32
output pin
*
Note: * Set the TE bit in SCR3 after setting this bit to 1.
Bit 4—Reserved
Bit 4 is reserved; it can only be written with 0.