ADC_DMA

功能实现：ADC DMA方式循环采样。

采集周期：（256-192）*16*Tsys = （256-192）*16/62.4M = 16.5us

进中断周期：16.5us*采集数据的长度 = 16.5us

int main()
{
    uint8_t      i;
    signed short RoughCalib_Value = 0; // ADC粗调偏差值
    uint32_t temp = 0;
    uint8_t adcchidx = 0;
 
    HSECFG_Capacitance(HSECap_18p);
    SetSysClock(CLK_SOURCE_HSE_PLL_62_4MHz);
 
    /* 配置串口调试 */
    DebugInit();
    PRINT("Start @ChipID=%02X\n", R8_CHIP_ID);
 
    GPIOA_ResetBits(GPIO_Pin_1);
    GPIOA_ModeCfg(GPIO_Pin_1, GPIO_ModeOut_PP_5mA);
 
    /* DMA单通道采样：选择adc通道0做采样，对应 PA4引脚 */
    PRINT("\n3.Single channel DMA sampling...\n");
    GPIOA_ModeCfg(GPIO_Pin_4, GPIO_ModeIN_Floating);
    ADC_ExtSingleChSampInit(SampleFreq_8_or_4, ADC_PGA_0);
    ADC_ChannelCfg(0);
    ADC_ExcutSingleConver();//时间足够时建议再次转换并丢弃首次ADC数据
    ADC_AutoConverCycle(192); // 采样周期为 (256-192)*16个系统时钟
    ADC_DMACfg(ENABLE, (uint32_t)&adcBuff[0], (uint32_t)&adcBuff[1], ADC_Mode_LOOP);
    PFIC_EnableIRQ(ADC_IRQn);
    ADC_StartAutoDMA();
 
    while(1);
}
 
__INTERRUPT
__HIGH_CODE
void ADC_IRQHandler(void) //adc中断服务程序
{
    GPIOA_InverseBits(GPIO_Pin_1);
    if(ADC_GetDMAStatus())
    {
        R32_ADC_DMA_BEG = ((uint32_t)adcBuff) & 0x1ffff;
        ADC_ClearDMAFlag();
    }
}