mark0668 发表于 2015-3-11 15:29
你ADC 是什么触发的？

GPIO管脚中断触发。

ataudio 发表于 2015-3-11 15:34
GPIO管脚中断触发。

你采集几个AD值？

AD配置发一下，让大家一块分析一下。

安 发表于 2015-3-12 08:52
AD配置发一下，让大家一块分析一下。

ADC和DMA是一起配置的。ADC3_RAM_SIZE 是360

1. void ADC3_CH11_DMA_Config(void)
   
2. {
   
3.     ADC_InitTypeDef       ADC_InitStructure;
   
4.     ADC_CommonInitTypeDef ADC_CommonInitStructure;
   
5.     DMA_InitTypeDef       DMA_InitStructure;
   
6.     GPIO_InitTypeDef      GPIO_InitStructure;
   
7. 
   
8.     /* Enable ADC3, DMA2 and GPIO clocks ****************************************/
   
9.     RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOC, ENABLE );
   
10.     RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC3, ENABLE);
    
11. 
    
12.     /* DMA2 Stream0 channel0 configuration **************************************/
    
13.     DMA_InitStructure.DMA_Channel = DMA_Channel_2;  
    
14.     DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC3_DR_ADDRESS;
    
15.     DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADC3ConvertedValue;
    
16.     DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
    
17.     DMA_InitStructure.DMA_BufferSize = ADC3_RAM_SIZE;
    
18.     DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    
19.     DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
    
20.     DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
    
21.     DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
    
22.     DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
    
23.     DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    
24.     DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;         
    
25.     DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
    
26.     DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
    
27.     DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
    
28.     DMA_Init(DMA2_Stream0, &DMA_InitStructure);
    
29.     // DMA中断注册
    
30.     DMA_ITConfig(DMA2_Stream0, DMA_IT_TC, ENABLE);
    
31.     DMA_Cmd(DMA2_Stream0, ENABLE);
    
32. 
    
33.     /* Configure ADC3 Channel12 pin as analog input *****************************/
    
34.     GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
    
35.     GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
    
36.     GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
    
37.     GPIO_Init(GPIOC, &GPIO_InitStructure);
    
38. 
    
39. 
    
40.     /* ADC Common Init **********************************************************/
    
41.     ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
    
42.     ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
    
43.     ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled ;
    
44.     ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
    
45.     ADC_CommonInit(&ADC_CommonInitStructure);
    
46. 
    
47.     /* ADC3 Init ****************************************************************/
    
48.     ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
    
49.     ADC_InitStructure.ADC_ScanConvMode = DISABLE;
    
50.     ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
    
51.     ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
    
52.     ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
    
53.     ADC_InitStructure.ADC_NbrOfConversion = 1;
    
54.     ADC_Init(ADC3, &ADC_InitStructure);
    
55. 
    
56.     /* ADC3 regular channel12 configuration *************************************/
    
57. 
    
58.     ADC_RegularChannelConfig(ADC3, ADC_Channel_11, 1, ADC_SampleTime_3Cycles);
    
59.     //ADC_RegularChannelConfig(ADC3, ADC_Channel_13, 2, ADC_SampleTime_3Cycles);
    
60. 
    
61.     /* Enable DMA request after last transfer (Single-ADC mode) */
    
62.     ADC_DMARequestAfterLastTransferCmd(ADC3, ENABLE);
    
63. 
    
64.     /* Enable ADC3 DMA */
    
65.     ADC_DMACmd(ADC3, ENABLE);
    
66. 
    
67.     /* Enable ADC3 */
    
68.     ADC_Cmd(ADC3, ENABLE);
    
69. }

复制代码

mark0668 发表于 2015-3-11 15:41
你采集几个AD值？

一个ADC通道，每次采集360个点。

With ADCCLK = 30 MHz and sampling time = 3 cycles:
Tconv = 3 + 12 = 15 cycles = 0.5 μs with APB2 at 60 MHz
根据上面的计算，3个周期，12位数据，在APB2 60Mhz时，转换一次需要0.5us，楼主配置的DMA的缓冲区大小是多少？

还没有学到，过来看看

先关注一下！

智能绑定了

安 发表于 2015-3-12 09:56
With ADCCLK = 30 MHz and sampling time = 3 cycles:
Tconv = 3 + 12 = 15 cycles = 0.5 μs with APB2 at ...

缓冲区360个点，720字节。