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关于TMS320F28035 ADC单元的问题



问题1:请问AD单元手册12页的滤波时间2ns是指哪个滤波器呢?这个2ns是如何计算出来的呢?

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对于Dummy的问题,Errata中的描述如下:

从描述的内容看,问题出现在初始化阶段,如果系统可以接受初始化时的IDDA,那么不进行Dummy操作也可以

在例程Example_2803xAdcSoc中,有如下配置:

   EALLOW;
   AdcRegs.ADCCTL1.bit.INTPULSEPOS = 1; //ADCINT1 trips after AdcResults latch
   AdcRegs.INTSEL1N2.bit.INT1E      = 1; //Enabled ADCINT1
   AdcRegs.INTSEL1N2.bit.INT1CONT   = 0; //Disable ADCINT1 Continuous mode
   AdcRegs.INTSEL1N2.bit.INT1SEL = 2; //setup EOC2 to trigger ADCINT1 to fire
   AdcRegs.ADCSOC0CTL.bit.CHSEL  = 4; //set SOC0 channel select to ADCINA4(dummy sample for rev0 errata workaround)
   AdcRegs.ADCSOC1CTL.bit.CHSEL  = 4; //set SOC1 channel select to ADCINA4
   AdcRegs.ADCSOC2CTL.bit.CHSEL  = 2; //set SOC2 channel select to ADCINA2
   AdcRegs.ADCSOC0CTL.bit.TRIGSEL  = 5; //set SOC0 start trigger on EPWM1A, due to round-robin SOC0 converts first then SOC1, then SOC2
   AdcRegs.ADCSOC1CTL.bit.TRIGSEL  = 5; //set SOC1 start trigger on EPWM1A, due to round-robin SOC0 converts first then SOC1, then SOC2
   AdcRegs.ADCSOC2CTL.bit.TRIGSEL  = 5; //set SOC2 start trigger on EPWM1A, due to round-robin SOC0 converts first then SOC1, then SOC2
   AdcRegs.ADCSOC0CTL.bit.ACQPS  = 6; //set SOC0 S/H Window to 7 ADC Clock Cycles, (6 ACQPS plus 1)
   AdcRegs.ADCSOC1CTL.bit.ACQPS  = 6; //set SOC1 S/H Window to 7 ADC Clock Cycles, (6 ACQPS plus 1)
   AdcRegs.ADCSOC2CTL.bit.ACQPS  = 6; //set SOC2 S/H Window to 7 ADC Clock Cycles, (6 ACQPS plus 1)
   EDIS;

问题2:如上所示,每次触发3个通道,第一个通道的数据是没有用的,这样会占用一些采样时间,如果没有Dummy,是不是也是可以?