初试GD32F103C8T6

一、电路板功能：

1、GPIO直驱4位共阳数码管
2、ADC+DMA采集2路电压信号
3、CAN通讯
4、LED指示灯
5、串口1通讯
6、定时器TIM2

二、使用STM32固件库V3.5、RTT/OS

硬件外部晶振8Mhz、代码初始化后主频无修改，默认72Mhz，可用以下代码获取时钟信息

RCC_GetClocksFreq(&RCC_Clocks);

经测试，直接使用原STM32代码，发现ADC使用DMA无法读取数据，其他几个功能正常。
现修改DMA+ADC时钟初始化顺序，问题解决

三、ADC+DMA初始化代码

static void ADC1_GPIO_Config(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    /* Enable ADC1 and GPIOC clock */
    RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOA, ENABLE);

    /* Configure PA.03、PA.04  as analog input */
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3|GPIO_Pin_4;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
}

static void ADC1_Mode_Config(void)
{
    DMA_InitTypeDef DMA_InitStructure;
    ADC_InitTypeDef ADC_InitStructure;
    /* Enable DMA clock */
    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
    /* Enable ADC1 clock */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 , ENABLE);

    /* DMA channel1 configuration */
    DMA_DeInit(DMA1_Channel1);
    DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_Address;	
    DMA_InitStructure.DMA_MemoryBaseAddr = (u32)&psysADC;

    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
    DMA_InitStructure.DMA_BufferSize = 2;
    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;

    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
    DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
    DMA_Init(DMA1_Channel1, &DMA_InitStructure);

    /* Enable DMA channel1 */
    DMA_Cmd(DMA1_Channel1, ENABLE);

    /* ADC1 configuration */

    ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
    ADC_InitStructure.ADC_ScanConvMode = ENABLE ; 
    ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
    ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
    ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right; 
    ADC_InitStructure.ADC_NbrOfChannel = 2;
    ADC_Init(ADC1, &ADC_InitStructure);

    RCC_ADCCLKConfig(RCC_PCLK2_Div8);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 1, ADC_SampleTime_55Cycles5);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_4, 2, ADC_SampleTime_55Cycles5);
    /* Enable ADC1 DMA */
    ADC_DMACmd(ADC1, ENABLE);

    /* Enable ADC1 */
    ADC_Cmd(ADC1, ENABLE);

    ADC_ResetCalibration(ADC1);
    /* GD32 Need USE This Delay  */
    usDelay(10*1000);
    while(ADC_GetResetCalibrationStatus(ADC1));

    ADC_StartCalibration(ADC1);
    while(ADC_GetCalibrationStatus(ADC1));

    ADC_SoftwareStartConvCmd(ADC1, ENABLE);
}