
APPLICATION
2.3 Serial I/O
2-49
3802 GROUP USER’S MANUAL
Fig. 2.3.38 Setting of related registers at a transmitting side [Communication using UART]
Serial I/O1 status register (Address : 1916)
SIO1STS
Transmitting side
Baud rate generator (Address : 1C16)
BRG
7
SIO1CON 10 0 1
0 1
0
UART control register (Address : 1B16)
UARTCON
0
01
0
f(XIN)
Transfer bit rate
16
m
1
–
b7
b0
Serial I/O1 control register (Address : 1A16)
b7
b0
b7
b0
b7
b0
Set
when bit 0 of the Serial I/O1 control register (Address : 1A16) is set to “0,”
a value of m is 1.
when bit 0 of the Serial I/O1 control register (Address : 1A16) is set to “1,”
a value of m is 4.
T
BRG count source selection bit : f(XIN)/4
Serial I/O1 synchronous clock selection bit : BRG/16
Transmit enable bit : Transmit enabled
Receive enable bit : Receive disabled
Serial I/O1 mode selection bit : Asynchronous serial I/O(UART)
Serial I/O1 enable bit : Serial I/O1 enabled
SRDY1
output enable bit : Not use SRDY1 out
Character length selection bit : 8 bits
Parity enable bit : Parity checking disabled
P45/TXD P-channel output disable bit : CMOS output
Stop bit length selection bit : 2 stop bits
Transmit buffer empty flag
Check to be transferred data from the Transmit buffer
register to the Transmit shift register.
Writable the next transmission data to the Transmit buffer
register at being set to “1.”
Transmit shift register shift completion flag
Check a completion of transmitting 1-byte data with this flag.
“1” : Transmit shift completed