Panasonic MN103S User Manual page 366

Chapter 12
Serial interface 0 and 1
Setting Data I/O Pin
2 channels (data output pin (SBO pin), data input pin (SBIn pin)) are used for communication.
Reception Data Flag Operation
Data is automatically stored to SCnRB from the internal shift register when the reception complete interrupt SCn-
RIRQ is generated. If data is stored in the shift register SCnRB, the reception data flag SCAnRXA of the SCnSTR
register is set to "1". This indicates that reception data is ready to be read out. SCAnRXA is cleared to "0" by
reading out SCnRB data.
Reception BUSY Flag Operation
When a start condition is recognized, the SCAnRBSY flag of the SCnSTR register is set to "1". It is cleared to "0"
after the reception complete interrupt SCnRIRQ is generated.
Transmission BUSY Flag Operation
When SCnTB data is set, the SCAnTBSY flag of the SCnSTR register is set to "1". Is is cleared to "0" after the
transmission complete interrupt SCnTIRQ is generated.
Reception Error
Errors at reception have 3 types, overrun error, parity error, and framing error. Reception error can be determined
by the SCAnOE, SCAnPE and SCAnFE flags of the SCnSTR register. The SCAnPE and SCAnFE flags of the
reception error flags are renewed at generation of the communication complete interrupt SCnRIRQ. After reading
data of SCnRB, The SCAnOE flag is cleared at the same time when the next communication complete interrupt
SCnRIRQ is generated. The judgement of the reception error flag should be operated until the next communica-
tion is completed. These error flags have no effects on communication operation. The reception error source is
shown in the following table.
Table:12.3.7 Reception Error Source of UART Serial InterfaceS
Flag
SCAnOE
SCAnPE
SCAnFE
Continuous Communication
This serial has no continuous transfer function. Do not set data in the transmission data buffer SCnTB during
transmission.
XII - 20 Operation
Reception error
Overrun error The next data is received before the reception buffer is read.
Fixed to 0
Fixed to 1
Odd parity
Parity error
Even parity
Framing error Stop bit is not detected.
When parity bit is "1"
When parity bit is "0"
When the total of "1" of parity bit and character bit is
even
When the total of "1" of parity bit and character bit is
odd