
ML610Q431/ML610Q432 User’s Manual
Chapter 14
Synchronous Serial Port
14 – 6
14.2.4
Serial Port Mode Register 0 (SIO0MOD0)
Address: 0F284H
Access: R/W
Access size: 8 bits
Initial value: 00H
7
6
5
4
3
2
1
0
SIO0MOD0
S0LG
S0MD1
S0MD0
S0DIR
R/W
Initial value
0
SIO0MOD0 is a special function register (SFR) to set mode of the synchronous serial port.
[Description of Bits]
S0DIR (bit 0)
The S0DIR is used to select LSB first or MSB first.
S0DIR
Description
0
LSB first (initial value)
1
MSB first
S0MD1, S0MD0 (bits 2, 1)
The S0MD1 and S0MD0 bits are used to select transmit, receive, or transmit/receive mode of the synchronous serial
port.
S0MD1
S0MD0
Description
0
Stops transmission/reception (initial value)
0
1
Receive mode
1
0
Transmit mode
1
Transmit/receive mode
S0LG (bit 3)
The S0LG bit is used to specify the bit length of the transmit/receive buffer, 8-bit or 16-bit length.
The S0LG bit is set to “0” at a system reset.
S0LG
Description
0
8-bit length (initial value)
1
16-bit length
Note:
Do not change any of the SIO0MOD0 register settings during transmission/reception.
When the synchronous serial port is used, the tertiary functions of GPIO must be set. For the tertiary functions of Port
4, see Chapter 22, “Port 4”.