我的DMA方式输出DAC初始化有没有错误？怎么没有数据输出？

sgsg · 发表于 2014-9-29 18:04:21

我的DMA方式输出DAC初始化有没有错误？怎么没有数据输出？调试后发现在主程序里把值赋给 DAC_ConvertedValue后，DMA好像并没有把这个值传到DAC进行输出。我的初始化错在哪里？

#include "dac.h"
#include "dma.h"

#define DAC1_DHR12R1_Address ((u32)0x40007408)

__IO u16 DAC_ConvertedValue;

void Dac1_Init(void)
{
DMA_InitTypeDef DMA_InitStructure;

GPIO_InitTypeDef GPIO_InitStructure;
DAC_InitTypeDef DAC_InitType;

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE );
RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE );
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_SetBits(GPIOA,GPIO_Pin_4) ;

/* DMA2 channel3 configuration */
DMA_DeInit(DMA2_Channel3);
DMA_InitStructure.DMA_PeripheralBaseAddr = DAC1_DHR12R1_Address;
DMA_InitStructure.DMA_MemoryBaseAddr = (u32)&DAC_ConvertedValue;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
DMA_InitStructure.DMA_BufferSize = 1;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;
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(DMA2_Channel3, &DMA_InitStructure);

/* Enable DMA channel1 */
DMA_Cmd(DMA2_Channel3, ENABLE);

DAC_InitType.DAC_Trigger=DAC_Trigger_None;
DAC_InitType.DAC_WaveGeneration=DAC_WaveGeneration_None;
DAC_InitType.DAC_LFSRUnmask_TriangleAmplitude=DAC_LFSRUnmask_Bit0;
DAC_InitType.DAC_OutputBuffer=DAC_OutputBuffer_Disable ;
DAC_Init(DAC_Channel_1,&DAC_InitType);

DAC_Cmd(DAC_Channel_1, ENABLE);

/* Enable DAC_Channel_1 DMA */
DAC_DMACmd(DAC_Channel_1, ENABLE);

}