STM32L011 DMA ADC

采样PA0,PA1,内部温度传感器,内部基准参考,其中PA0接VCC,PA1悬空.

代码如下:

#include "stm32l0xx.h"
__IO uint32_t uwTick;
uint16_t pdata[100][4] = {0x00};
void DMA1_Channel1_IRQHandler(void)
{
    if( (DMA1->ISR & (0x00000002U)) != RESET)  /* DMA_FLAG_TC1 */
    {
        if((DMA1_Channel1->CCR & DMA_CCR_TCIE) != RESET)
        {
            if((DMA1_Channel1->CCR & DMA_CCR_CIRC) == 0U)
            {
                DMA1_Channel1->CCR &= ~(DMA_CCR_TCIE);
            }
            /* 清除中断标志位 */
            DMA1->IFCR = 0x00000002U; /* DMA_FLAG_TC1 */
            CLEAR_BIT(ADC1->CR, ADC_CR_ADEN);
            if(pdata[0][0] == 0xFFFF)
            {
                pdata[0][0] = 0xFFFF;/* UNUSED */
            }
        }
    }
}
void SysTick_Delay(__IO uint32_t Delay)
{
    uint32_t tickstart = 0U;
    tickstart = uwTick;
    while((uwTick - tickstart) < Delay)
    {
    }
}
void RCC_Init(void)
{
    /* LSE OFF,LSI DEFAULT,MSI OFF,HSI ON,PLL ON,SYSCLK = 32MHz,CK_PWR = FCLK = HCLK = SysTick = APB1 = APB2 = 32MHz.*/
    FLASH->ACR = FLASH_ACR_PRE_READ | FLASH_ACR_PRFTEN;
    MODIFY_REG(PWR->CR, PWR_CR_VOS, (PWR_CR_VOS_0));
    MODIFY_REG(RCC->CR, RCC_CR_HSION | RCC_CR_HSIDIVEN , RCC_CR_HSION);
    while(READ_BIT(RCC->CR, RCC_CR_HSIRDY) == RESET);
    MODIFY_REG(RCC->ICSCR, RCC_ICSCR_HSITRIM, (uint32_t)(16) << 8U);
    CLEAR_BIT(RCC->CR, RCC_CR_PLLON);
    while(READ_BIT(RCC->CR, RCC_CR_PLLRDY) != RESET);
    MODIFY_REG(RCC->CFGR, RCC_CFGR_PLLMUL | RCC_CFGR_PLLDIV | RCC_CFGR_PLLSRC, (uint32_t)((RCC_CFGR_PLLMUL4) | (RCC_CFGR_PLLDIV2) | (RCC_CFGR_PLLSRC_HSI)));
    SET_BIT(RCC->CR, RCC_CR_PLLON);
    while(READ_BIT(RCC->CR, RCC_CR_PLLRDY) == RESET);
    MODIFY_REG(FLASH->ACR, FLASH_ACR_LATENCY, (uint32_t)(0x01U));
    MODIFY_REG(RCC->CFGR, RCC_CFGR_HPRE, RCC_CFGR_HPRE_DIV1);
    MODIFY_REG(RCC->CFGR, RCC_CFGR_SW, RCC_CFGR_SW_PLL);
    while ((uint32_t)(RCC->CFGR & RCC_CFGR_SWS) != RCC_CFGR_SWS_PLL);
    MODIFY_REG(RCC->CFGR, RCC_CFGR_PPRE1, RCC_CFGR_PPRE1_DIV1);
    MODIFY_REG(RCC->CFGR, RCC_CFGR_PPRE2, ((RCC_CFGR_PPRE1_DIV1) << 3));
    CLEAR_BIT(RCC->CR, RCC_CR_MSION);
    /* SysTick CLK = 4MHz,Reload = 1kHz. */
    SysTick->LOAD  = (uint32_t)0x00000F9FUL;
    NVIC_SetPriority (SysTick_IRQn, (1UL << __NVIC_PRIO_BITS) - 1UL);
    SysTick->VAL   = 0UL;
    SysTick->CTRL  = SysTick_CTRL_TICKINT_Msk | SysTick_CTRL_ENABLE_Msk;
    /* SysTick->CTRL  = SysTick_CTRL_TICKINT_Msk; */
}
void ADC_GetVDD_Voltage(void)
{
    /* 初始化时钟 */
    SET_BIT(RCC->APB2ENR, (RCC_APB2ENR_ADC1EN));
    SET_BIT(RCC->AHBENR, (RCC_AHBENR_DMAEN));
    SET_BIT(RCC->IOPENR, RCC_IOPENR_GPIOAEN);
    DMA1_Channel1->CCR = 0x00000580;
    DMA1_CSELR->CSELR &= ~DMA_CSELR_C1S;
    DMA1_CSELR->CSELR |= 0x00000000U; /* DMA_REQUEST_0 */
    /* 上电没配置过,默认除了JTAG外引脚都是模拟引脚,所以懒得配置了. */
    /* 初始化相关寄存器 */
    ADC1->CFGR1 = 0x0000A000; /* DMA 允许 + AUTO OFF(自动降低功耗) */
    ADC1->CFGR2 = 0x00002000; /* 连续采样模式,这样就不用每次都Start. */
    ADC->CCR = 0x00C00000; /* Vref + Temp Sensor */
    ADC1->SMPR = 0x00000007; 	/* 采样时间寄存器,0 = 1.14Msps,1 = 1Msps,2 = 800Ksps,3 = 640Ksps,4 = 500Ksps,5 = 308Ksps,6 = 174Ksps,7 = 92ksps, @ 16MHz */
    ADC1->CHSELR = 0x00060003; /* PA0 + PA1 + Temp + Vref,其中PA0通过短路帽接到了VCC. */
    /* 采样时间和结果区别:0 = 3625mV 1 = 3302mV 2 = 3190mV 3 = 3244mV 4 = 3317mV 5 = 3302mV 6 = 3302mV 7 = 3302mV */
    /* 校准ADC */
    SET_BIT(ADC1->CR, ADC_CR_ADCAL);
    while(READ_BIT(ADC1->CR, ADC_CR_ADCAL));
    SET_BIT(ADC1->CR, ADC_CR_ADEN);
    SET_BIT(ADC1->CFGR1, ADC_CFGR1_DMAEN);
    CLEAR_BIT(DMA1_Channel1->CCR, DMA_CCR_EN);
    DMA1_Channel1->CNDTR = 400;
    DMA1_Channel1->CMAR = (uint32_t)&pdata;
    DMA1_Channel1->CPAR = (uint32_t) & (ADC1->DR);
    SET_BIT(DMA1_Channel1->CCR, DMA_CCR_TCIE);
    SET_BIT(DMA1_Channel1->CCR, DMA_CCR_EN);
    SET_BIT(ADC1->CR, ADC_CR_ADSTART);
    NVIC_SetPriority(DMA1_Channel1_IRQn, 0);
    NVIC_EnableIRQ(DMA1_Channel1_IRQn);
}
int main(void)
{
    RCC_Init();
    ADC_GetVDD_Voltage();
    while (1)
    {
        SysTick_Delay(1000);
        SET_BIT(ADC1->CR, ADC_CR_ADEN);
        CLEAR_BIT(DMA1_Channel1->CCR, DMA_CCR_EN);
        DMA1_Channel1->CNDTR = 400;
        DMA1_Channel1->CMAR = (uint32_t)&pdata;
        DMA1_Channel1->CPAR = (uint32_t) & (ADC1->DR);
        SET_BIT(DMA1_Channel1->CCR, DMA_CCR_TCIE);
        SET_BIT(DMA1_Channel1->CCR, DMA_CCR_EN);
        SET_BIT(ADC1->CR, ADC_CR_ADSTART);
    }
}