342
SCSR1—Serial control/status register 1
H'A1
SCI1
Bit
Initial value
Read/Write
7
—
1
—
6
SOL
0
R/W
5
ORER
0
R/(W)
4
—
1
—
3
—
1
—
0
STF
0
R/W
2
—
1
—
1
—
0
R
Extended data bit
Overrun error flag
0
Read
Write
*
Start flag
0
Indicates that transfer is stopped
Invalid
1
Read
Write
Read
Write
Indicates transfer in progress
Starts a transfer operation
1
Read
Write
SO
1
pin output level is low
SO
1
pin output level changes to low
SO
1
pin output level is high
SO
1
pin output level changes to high
Note: Only a write of 0 for flag clearing is possible.
*
0
[Clearing condition]
After reading 1, cleared by writing 0
1
[Setting condition]
Set if a clock pulse is input after transfer
is complete, when an external clock is used
SDRU—Serial data register U
H'A2
SCI1
Bit
Initial value
Read/Write
7
SDRU7
Undefined
R/W
6
SDRU6
Undefined
R/W
5
SDRU5
Undefined
R/W
4
SDRU4
Undefined
R/W
3
SDRU3
Undefined
R/W
0
SDRU0
Undefined
R/W
2
SDRU2
Undefined
R/W
1
SDRU1
Undefined
R/W
Stores transmit and receive data
8-bit transfer mode:
16-bit transfer mode:
Not used
Upper 8 bits of data