MM32F031K6T的ADC转换速率好像达不到1Msps

只看该作者 · 2022-2-26 11:20

我使用库例程，时钟使用HSI，72MHz，APB2不分频；ADC_PRESCARE设置为12；
设置采样通道2个，通道采样时间在55.5周期以上，符合数据手册。但如果采样时间设置为13.5周期，却达不到111ksps，任何低于55.5周期的设置，都只能达到65ksps左右；或者ADC_PRESCARE设置为11及以下，提高ADC时钟，也都只能达到65ksps左右；请问瓶颈在哪儿？下面是ADC配置和时钟配置

//ADC配置，2个采样通道
void ADCMultiChannelInit(){
GPIO_Config_AIN(GPIOA, GPIO_Pin_1);
  GPIO_Config_AIN(GPIOA, GPIO_Pin_3);

ADC_InitTypeDef  ADC_InitStructure;
ADC_StructInit(&ADC_InitStructure);

//Initialize PA1 to analog input mode
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);                      //Enable ADC clock

ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_PRESCARE = ADC_PCLK2_PRESCARE_12;                   //ADC prescale factor
ADC_InitStructure.ADC_Mode = ADC_Mode_Continuous_Scan;                   //Set ADC mode to continuous conversion mode
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;                   //AD data right-justified
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;
ADC_Init(ADC1, &ADC_InitStructure);

ADC_RegularChannelConfig(ADC, ADC_Channel_DisableAll, 0, ADC_SampleTime_13_5Cycles);//Block all channels
ADC_RegularChannelConfig(ADC1, ADCch1, 0, ADC_SampleTime_13_5Cycles);//Enable the channel
ADC_RegularChannelConfig(ADC1, ADCch2, 0, ADC_SampleTime_13_5Cycles);//Enable the channel

#ifdef ADC_USE_DMA
ADC_DMACmd(ADC1, ENABLE);                                                 //Enable ADCDMA
#else
ADC_ITConfig(ADC1, ADC_IT_EOC, ENABLE);                            //DMA interrupt initialization
NVIC_InitTypeDef NVIC_InitStruct;
NVIC_InitStruct.NVIC_IRQChannel = ADC_COMP_IRQn;
NVIC_InitStruct.NVIC_IRQChannelPriority = 0;
NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStruct);
#endif
ADC_Cmd(ADC1, ENABLE);                                                    //Enable AD conversion
}

//DMA配置
void ADC_DMAInit(void)
{
DMA_InitTypeDef DMA_InitStructure;
NVIC_InitTypeDef NVIC_InitStruct;

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
DMA_DeInit(DMA1_Channel1);
DMA_InitStructure.DMA_PeripheralBaseAddr = (u32) & (ADC1->ADDATA);          //DMA transfer peripheral address
DMA_InitStructure.DMA_MemoryBaseAddr = (u32)&ADCValue;                   //DMA transfer memory address
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;                         //DMA transfer direction from peripheral to memory
DMA_InitStructure.DMA_BufferSize = 2;                         //DMA cache size
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;          //After receiving the data, the peripheral address is forbidden to move backward
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;                   //After receiving the data, the memory address is shifted backward
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord; //Define the peripheral data width to 16 bits
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;       //Define the memory data width to 16 bits
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;                            //Cycle conversion mode
DMA_InitStructure.DMA_Priority = DMA_Priority_High;                      //DMA priority is high
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;                               //M2M mode is disabled
DMA_Init(DMA1_Channel1, &DMA_InitStructure);
DMA_Cmd(DMA1_Channel1, ENABLE);

DMA_ITConfig(DMA1_Channel1, DMA_IT_TC, ENABLE);                            //DMA interrupt initialization
NVIC_InitStruct.NVIC_IRQChannel = DMA1_Channel1_IRQn;
NVIC_InitStruct.NVIC_IRQChannelPriority = 0;
NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStruct);

ADCTrigFilterflag = 0;
}

//ADCDMA中断处理
u32 measCount;
void DMA1_Channel1_IRQHandler(void)
{
// ADC_SoftwareStartConvCmd(ADC1, DISABLE);                                  //Stop Conversion
DMA_ClearITPendingBit(DMA1_IT_TC1);                                        //Clear interrupt flag
u16 chan = 0;
measCount++;
// ADC_SoftwareStartConvCmd(ADC1, ENABLE);
// ADCflag = 1;                                                             //Erected transmission complete flag

}

//72M时钟配置
void SetSysClockTo72_HSI(void)
{
unsigned char temp = 0;
unsigned int temp1 = 0;
RCC->CR |= RCC_CR_HSION;
while (!(RCC->CR & RCC_CR_HSIRDY))
      ;

RCC->CR |= (1 << 20);

RCC->CR &= ~(1 << 2);

RCC->CFGR = RCC_CFGR_PPRE1_2;

FLASH->ACR = FLASH_ACR_LATENCY_2 | FLASH_ACR_PRFTBE;
RCC->CFGR |= (uint32_t)RCC_CFGR_HPRE_DIV1;

/* PCLK2 = HCLK PRE2 divide*/
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE2_DIV1;

/* PCLK1 = HCLK PRE1 divide */
RCC->CFGR |= (uint32_t)RCC_CFGR_PPRE1_DIV1;
RCC->CFGR &= ~RCC_CFGR_SW;

temp1 = *(u16 *)0x1FFFF7FA;
if ((temp1 & 0xff) == 0xff) {
      temp1 &= 0xff00;
} else {
      temp1 &= 0xff;
      temp1 <<= 8;
}
temp1 |= (RCC->CR & 0xFFFF00ff) | 0xf8;
RCC->CR = temp1;
RCC->CFGR |= RCC_CFGR_SW_HSI;

while (1) {
      temp = RCC->CFGR;
      temp = temp >> 2;
      temp &= RCC_CFGR_SW;
      if(temp == RCC_CFGR_SW_HSI)
         break;
}
}

只看该作者 · 2022-2-28 10:15

本帖最后由 deadphenix 于 2022-2-28 10:22 编辑

发现不是ADC的问题，而是PWM的问题，我在ADCDMA转换中设置了TIM的比较寄存器CCR1，这个突然占用了很大的开销。如果在ADC的DMA中断中屏蔽掉“TIM_SetCompare1(TIM1, 200);“，则ADC转换时间是正常的，但加上该句之后，就很耗时了，按理这个应该很快才对，为什么TIM1->CCR1的设置会很耗时呢？

void DMA1_Channel1_IRQHandler(void)
{
//       ADC_SoftwareStartConvCmd(ADC1, DISABLE);                                  //Stop Conversion
      DMA_ClearITPendingBit(DMA1_IT_TC1);                                        //Clear interrupt flag
      u16 chan = 0;
      measCount++;
      TIM_SetCompare1(TIM1, 200);
//             ADC_SoftwareStartConvCmd(ADC1, ENABLE);
// ADCflag = 1;                                                             //Erected transmission complete flag

}

void PWM_TIM1_ConfigInit()
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_2);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;                                  //TIM1_CH1
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);

TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
TIM_TimeBaseStructure.TIM_Period = 400;
TIM_TimeBaseStructure.TIM_Prescaler = 6;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 100;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);

TIM_ARRPreloadConfig(TIM1, ENABLE);
TIM_Cmd(TIM1, ENABLE);

TIM_CtrlPWMOutputs(TIM1, ENABLE);
}