Chapter 13Serial Interface 2Operation XIII - 17■ Transmission BUSY Flag OperationThe SC2TBSY flag of the SC2STR register is set if the SC2SBOS flag of the SC2CTR1 register is set to “1”when data is set in SC2TB or a when a start condition is recognized while “serial data output” is selected with theSC2SBOS flag of the SC2CTR1 register. The SC2TBSY flag is cleared to “0” after generation of the communica-tion end interrupt SC2TIRQ. The SC2TBSY flag setting is maintained during continuous communication. Iftransmission buffer empty flag SC2TEMP is set to”0” when the communication complete interrupt SC2TIRQ isgenerated, SC2RBSY is cleared to “0”. The SC2TBSY flag is reset to “0” when the SC2SBOS flag is cleared to“0” during communication.■ Overrun Error and Error Monitor Flag OperationAfter reception is completed, if reception of the next data is completed before data is read from the reception databuffer SC2RB, overrun error occurs and the SC2ORE flag of the SC2STR register is set to “1”. At the same time,the error monitor flag SC2ERE is set, indicating that the reception has an error. The SC2ERE flag is cleared afterthe next communication complete interrupt SC2TIRQ is generated since data is read from SC2RB. The SC2EREflag is cleared along with the SC2ORE flag . These error flags have no effects on communication.■ Continuous TransmissionThis serial is equipped with a continuous transmission function. If data is set in the transmission data bufferSC2TB during communication, the transmission buffer empty flag SC2TEMP is set; thus, allowing automatic,continuous communication. Set data to SC2TB the period that after data is loaded to the transmission shift registerand before the communication end interrupt SC2IRQ is generated. In master communication, communicationblank from SC2TIRQ generation to next transfer clock output is 4 transfer clock.■ Forced ResetThis serial interface is equipped with a forced reset function to address abnormal operation. Communication canbe shut down by setting both the SC2SBOS and SC2SBIS flags of the SC2CTR1 register to “0” (SBO2 pin func-tion: port, input data: “1” input). When a force reset is done, the status registers (the SC2BRKF flag of theSC2CTR2 register, all flags of the SC2STR register) are initialized, but other control registers hold their set val-ues.
