277CHAPTER 14 A/D CONVERTER(2) A/D conversion operation in software startWhen bit 6 (TRG) and bit 7 (CS) of A/D converter mode register (ADM) are set to 0 and 1, respectively, theA/D conversion starts on the voltage applied to the analog input pins specified with bits 1 to 3 (ADM1 toADM3) of ADM.Upon termination of the A/D conversion, the conversion result is stored in the A/D conversion result register(ADCR) and the interrupt request signal (INTAD) is generated. After one A/D conversion operation is startedand terminated, the next A/D conversion operation starts immediately. The A/D conversion operationcontinues repeatedly until new data is written to ADM.If data with CS set to 1 is written to ADM again during A/D conversion, the converter suspends its A/Dconversion operation and starts A/D conversion on the newly written data.If data with CS set to 0 is written to ADM during A/D conversion, the A/D conversion operation stopsimmediately.Figure 14-9. A/D Conversion by Software StartRemarks 1. n = 0, 1, ... , 72. m = 0, 1, ... , 7Conversion StartCS=1, TRG=0A /D ConversionADCRINTADANIn ANIn ANImANIn ANIm ANImANInANInADM RewriteCS=1, TRG=0ADM RewriteCS=0, TRG=0Conversion suspendedConversion results arenot stored Stop
