Panasonic MN101C77C, F77G user manual Reception Error Source of Uart Serial Interface

Chapter 11 Serial Interface 0, 1

„Reception Error

At reception , there are 3 types of error ; overrun error, parity error and framing error. Reception error can be determined by the SCnORE, SCnPEK, SCnFEF flag of the SCnMD3 register. Even one of those errors is detected, the SCnERE flag of the SCnMD3 register is set to "1". The SCnPEK, the SCnFEF flags in recepption error flag are renewed at generation of the reception complete interrupt SCnRIRQ. The SCnORE flag is holded the status unless data of RXBUFn is read out. The judgements of the received error flag should be operated until the next communication is finished. The communication operation does not have any effect on those error flags . Table 11-3-21 shows the list of reception error source.

Table 11-3-21 Reception Error Source of UART Serial Interface

Flag	Error	Error source
SCnORE	Overrun error	Next data is received before reading the receive buffer.
		at fixed to 0	when parity bit is "1"
		at fixed to 1	when parity bit is "0"
SCnPEK	Parity error
		odd parity	The total of "1" of parity bit and character bit is
			even.
		even parity	The total of "1" of parity bit and character bit is
			odd.
SCnFEF	Framing error	Stop bit is not detected.

„Judgement of Break Status Reception

Reception at break status can be judged. If all received data from start bit to stop bit is "0", the SCnBRKF flag of the SCnMD2 register is set and regard the break status. The SCnBRKF flag is set at generation of the reception complete interrupt SCnRIRQ.

„Sequence Communication

It is possible to transfer continuously. If data is set to the transmission data buffer TXBUFn during communication, the transmission buffer empty flag SCnTEMP is set to continue the communication, automatically. In this case, there is no pause on communication. Data should be set to TXBUFn after data is loaded to the inside shift register before the communication complete interrupt SC0TIRQ is generated.

Also, this LSI has an automatic data transfer function ATC1 that can be one of an activation factor. At activation by ATC1, data can be transfered up to 255 bytes, continuously. In this case, there is a commu- nication blank ; up to 18 machine cycles + 3.5 bit data length. For an activation by ATC1, refer to chapter 15. automatic transfer controller, transfer mode 6 to 9.

XI - 46 Operation