CHAPTER 14 ASYNCHRONOUS SERIAL INTERFACE (UART)User’s Manual U16896EJ2V0UD 41714.5.5 Reception errorThe three types of errors that can occur during a receive operation are a parity error, framing error, and overrunerror. As a result of data reception, the various flags of the ASISn register are set (1), and a reception error interruptrequest signal (INTSREn) or a reception completion interrupt request signal (INTSRn) is generated at the same time.The ASIMn.ISRMn bit specifies whether the INTSREn signal or the INTSRn signal is generated.The type of error that occurred during reception can be detected by reading the contents of the ASISn registerduring the INTSREn or INTSRn interrupt servicing.The contents of the ASISn register are cleared (0) by reading the ASISn register.Table 14-3. Reception Error CausesError Flag Reception Error CausePEn Parity error The parity specification during transmission did not match the parity of the reception dataFEn Framing error No stop bit was detectedOVEn Overrun error The reception of the next data was completed before data was read from the RXBn register(1) Separation of reception error interrupt request signalA reception error interrupt request signal can be separated from the INTSRn signal and generated as theINTSREn signal by clearing the ISRMn bit to 0.Figure 14-8. When Reception Error Interrupt Request Signal Is Separated from INTSRn Signal (ISRMn Bit = 0)(a) No error occurs during reception (b) An error occurs during receptionINTSRn signal(Reception completioninterrupt)INTSREn signal(Reception errorinterrupt)INTSRn signal(Reception completioninterrupt)INTSREn signal(Reception errorinterrupt)INTSRndoes not occurFigure 14-9. When Reception Error Interrupt Request Signal Is Included in INTSRn Signal (ISRMn Bit = 1)(a) No error occurs during reception (b) An error occurs during receptionINTSRn signal(Reception completioninterrupt)INTSREn signal(Reception errorinterrupt)INTSRn signal(Reception completioninterrupt)INTSREn signal(Reception errorinterrupt) INTSREndoes not occur
