TI中文支持网最近在调试DSP-28377s,但是ADC有两路不对。试了50个DSP板子，有20是好的，30个是采样值有问题的。如下图所示：
1、有问题的
2、没问题的
ADC都是16位差分模式，红色的是.ADC–A0-A1通道,白色的是A2 -A3通道，绿色的是A4 – A5通道。
感觉采样值保持时间过长，A0-A1通道的值没问题，平滑曲线，但是A2 -A3，A4 – A5通道就有问题。
下边是我的配置：
void ADC_capture()
{
AdcaRegs.ADCSOCFRC1.all = 0x007F; //SOC0 and SOC1
while(AdcaRegs.ADCINTFLG.bit.ADCINT1 == 0);
AdcaRegs.ADCINTFLGCLR.bit.ADCINT1 = 1；
AdcaResult0 = AdcaResultRegs.ADCRESULT0; ///1--3
AdcaResult2 = AdcaResultRegs.ADCRESULT2;
AdcaResult4 = AdcaResultRegs.ADCRESULT4;
}
//Write ADC configurations and power up the ADC for both ADC A and ADC B
void ConfigureADC(void)
{
EALLOW;
//write configurations
AdcaRegs.ADCCTL2.bit.PRESCALE = 6; //set ADCCLK divider to /4
AdcSetMode(ADC_ADCA, ADC_RESOLUTION_16BIT, ADC_SIGNALMODE_DIFFERENTIAL);
AdcaRegs.ADCCTL1.bit.INTPULSEPOS = 1; // AdcaRegs.ADCCTL1.bit.INTPULSEPOS = 1;
AdcaRegs.ADCCTL1.bit.ADCPWDNZ = 1;
EDIS;
}
void SetupADCSoftware(void)
{
Uint16 acqps;
//determine minimum acquisition window (in SYSCLKS) based on resolution
if( 0 && ADC_RESOLUTION_12BIT == AdcaRegs.ADCCTL2.bit.RESOLUTION){
acqps = 14; //75ns
}
else { //resolution is 16-bit
acqps = 63; //63--320nS
}
//Select the channels to convert and end of conversion flag
//------------------ADCA-------------------------------------------------------
EALLOW;
AdcaRegs.ADCSOC0CTL.bit.CHSEL = 0; //SOC0 will convert pin A0
AdcaRegs.ADCSOC0CTL.bit.ACQPS = acqps; //sample win
AdcaRegs.ADCSOC1CTL.bit.CHSEL = 1; //SOC1 will convert pin A1
AdcaRegs.ADCSOC1CTL.bit.ACQPS = acqps; //sample window is acqps + 1 SYSCLK cycles
// AdcbRegs.ADCSOC1CTL.bit.TRIGSEL = 1;
AdcaRegs.ADCSOC2CTL.bit.CHSEL = 2; //SOC1 will convert pin A1
AdcaRegs.ADCSOC2CTL.bit.ACQPS = acqps; //sample window is acqps + 1 SYSCLK cycles
//AdcbRegs.ADCSOC2CTL.bit.TRIGSEL = 1;
AdcaRegs.ADCSOC3CTL.bit.CHSEL = 3; //SOC1 will convert pin A1
AdcaRegs.ADCSOC3CTL.bit.ACQPS = acqps; //sample window is acqps + 1 SYSCLK cycles
AdcaRegs.ADCSOC4CTL.bit.CHSEL = 4; //SOC1 will convert pin A1
AdcaRegs.ADCSOC4CTL.bit.ACQPS = acqps; //sample window is acqps + 1 SYSCLK cycles
//AdcbRegs.ADCSOC4CTL.bit.TRIGSEL = 1;
AdcaRegs.ADCSOC5CTL.bit.CHSEL = 5; //SOC1 will convert pin A1
AdcaRegs.ADCSOC5CTL.bit.ACQPS = acqps; //sample window is acqps + 1 SYSCLK cycles
AdcaRegs.ADCINTSEL1N2.bit.INT1SEL = 5; //end of SOC1 will set INT1 flag
AdcaRegs.ADCINTSEL1N2.bit.INT1E = 1; //enable INT1 flag
AdcaRegs.ADCINTFLGCLR.bit.ADCINT1= 1; //make sure INT1 flag is cleared
}
请问是哪里的问题，有没有人遇到和我一样的问题，谢谢！！
mangui zhang：从图看感觉是采样率低的原因。看看有问题板子的时钟 应该是跑的比较低
