Chapter 12
Serial interface 0 and 1
XII - 18 Operation
12.3.4 UART Serial Interface
■ Activation Factor for Communication
At transmission, if any data is set to the transmission data buffer SCnTB, a start condition is generated to start
transfer. At reception, if a start condition is received, communication is started. In reception, if the data length of
“L” for start bit is longer than 0.5 bit, that can be regarded as a start condition.
■ Transmission
Data transfer is automatically started by setting data to the transmission data buffer SCnTB. When the transmis-
sion is completed, the serial transmission interrupt SCnTIRQ is generated.
■ Reception
Once a start condition is received, the reception is started after the transfer bit counter that counts transfer bit is
cleared. When the reception is completed, the serial reception interrupt SCnRIRQ is generated.
■ Duplex Communication
On duplex communication, the transmission and reception can be operated separately at the same time. The frame
mode and parity bit of the used data on transmission / reception should have the same polarity.
■ Transmission Data Buffer
Refer to: XII-11
■ Reception Data Buffer
Refer to: XII-11
■ First Transfer Bit Setup
Refer to: XII-12
■ Transmission Bit Count and First Transfer Bit
Refer to: XII-12
■ Reception Bit Count and First Transfer Bit
Refer to: XII-12
To Next Page
