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3802 GROUP USER’S MANUAL
APPLICATION
2.3 Serial I/O
Fig. 2.3.19 Setting of related registers at a transmitting side [Communication using a clock
synchronous serial I/O]
Serial I/O1 status register (Address : 1916)
SIO1STS
Transmit buffer empty flag
Check to be transferred data from the Transmit buffer register to
Transmit shift register.
Writable the next transmission data to the Transmit buffer register
at being set to “1.”
Transmitting side
Transmit shift register shift completion flag
Check a completion of transmitting 1-byte data with this flag
“1” : Transmit shift completed
b7
b0
Interrupt edge selection register (Address : 3A16)
INTEDGE
INT0 active edge selection bit : Select INT0 falling edge
b7
b0
Baud rate generator (Address : 1C16)
BRG
Set “division ratio – 1”
7
b7
b0
Serial I/O1 control register (Address : 1A16)
SIO1CON
BRG counter source selection bit : f(XIN)
Serial I/O1 synchronous clock selection bit : BRG/4
Transmit enable bit : Transmit enabled
Receive enable bit : Receive disabled
Serial I/O1 mode selection bit : Clock synchronous serial I/O
Serial I/O1 enable bit : Serial I/O1 enabled
b7
b0
0
11
1
0