Hitachi H8/3937 Series Hardware Manual page 290

10. Serial Port Control Register (SPCR)
Bit 7
—
Initial value 1
Read/Write —
SPCR is an 8-bit readable/writable register that performs RXD
input/output data inversion switching. SPCR is initialized to H'C0 by a reset.
Bits 7 and 6: Reserved bits
Bits 7 and 6 are reserved; they are always read as 1 and cannot be modified.
Bit 5: P4 /TXD pin function switch (SPC32)
2 32
This bit selects whether pin P4
Bit 5
SPC32 Description
0 Functions as P4
1 Functions as TXD
Note: * Set the TE bit in SCR3 after setting this bit to 1.
Bit 4: P3 /TXD pin function switch (SPC31)
5 31
This bit selects whether pin P3
Bit 4
SPC31 Description
0 Functions as P3
1 Functions as TXD
Note: Set the TE bit in SCR3 after setting this bit to 1.
*
Bit 3: TXD pin output data inversion switch
32
Bit 3 specifies whether or not TXD
Bit 3
SCINV3 Description
0 TXD output data is not inverted
32
1 TXD output data is inverted
32
278
6 5 4
— SPC32 SPC31
1 0 0
— R/W R/W
/TXD is used as P4
2 32
I/O pin
2
output pin*
32
/TXD is used as P3
5 31
I/O pin
5
output pin*
31
pin output data is to be inverted.
32
3 2
SCINV3 SCINV2
0 0
R/W R/W
, RXD , TXD
31 32
or as TXD .
2 32
or as TXD .
5 31
1 0
SCINV1 SCINV0
0 0
R/W R/W
, and TXD pin
31 32
(initial value)
(initial value)
(initial value)