TIM7触发DAC2输出正弦波，使用DMA2_4传输，出不来波形。求指导。。。

jiutianshenjian · 发表于 2015-2-8 08:37:28

stm32f103zet6,TIM7触发DAC2输出正弦波，使用DMA2_4传输，出不来波形。求指导。。。
TIM7：
/*TIM7初始化*/
void TIM7_Int_Init(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    NVIC_InitTypeDef NVIC_InitStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM7, ENABLE); //时钟使能

    //定时器TIM7初始化
    TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值
    TIM_TimeBaseStructure.TIM_Prescaler = psc; //设置用来作为TIMx时钟频率除数的预分频值
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //设置时钟分割
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式
    TIM_TimeBaseInit(TIM7, &TIM_TimeBaseStructure); //根据指定的参数初始化TIMx的时间基数单位

TIM_ClearITPendingBit(TIM7, TIM_IT_Update); //清中断，避免一启用中断后立即产生中断
    TIM_ITConfig(TIM7, TIM_IT_Update, ENABLE ); //使能指定的TIM3中断,允许更新中断

TIM_SelectOutputTrigger(TIM7, TIM_TRGOSource_Update); //选择TIM7的update事件更新为触发源

//中断优先级NVIC设置
    NVIC_InitStructure.NVIC_IRQChannel = TIM7_IRQn; //TIM7中断
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //先占优先级0级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; //从优先级1级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure); //初始化NVIC寄存器

  TIM_Cmd(TIM7, ENABLE); //使能TIMx
}

void TIM7_IRQHandler(void)
{
if (TIM_GetITStatus(TIM7, TIM_IT_Update) != RESET)
{
TIM_ClearITPendingBit(TIM7, TIM_IT_Update); //清除中断标志位
}
}

DAC2：
void Dac2_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
DAC_InitTypeDef DAC_InitType;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); //使能PORTA通道时钟
RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE); //使能DAC通道时钟

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5; // 端口配置
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN; //模拟输入
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_SetBits(GPIOA,GPIO_Pin_5);//PA.5 输出高

DAC_InitType.DAC_Trigger=DAC_Trigger_T7_TRGO;//使用tim7触发
DAC_InitType.DAC_WaveGeneration=DAC_WaveGeneration_None;//不使用波形发生
DAC_InitType.DAC_LFSRUnmask_TriangleAmplitude=DAC_LFSRUnmask_Bit0;//屏蔽、幅值设置
DAC_InitType.DAC_OutputBuffer=DAC_OutputBuffer_Disable ; //DAC2输出缓存关闭 BOFF1=1
DAC_Init(DAC_Channel_2,&DAC_InitType); //初始化DAC通道2

DAC_DMACmd(DAC_Channel_2, ENABLE);
DAC_Cmd(DAC_Channel_2, ENABLE); //使能DAC2

DAC_SetChannel2Data(DAC_Align_8b_R, 0); //12位右对齐数据格式设置DAC值
}

DMA2：
void InitDma2(void)
{
DMA_InitTypeDef DMA_InitStructure;

/* DMA1 channel1 configuration ----------------------------------------------*/
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE);//使能DMA2时钟

DMA_DeInit(DMA2_Channel4);
DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)&(DAC->DHR8R2);//设置外设地址
DMA_InitStructure.DMA_MemoryBaseAddr = (u32)SinTab;//设置内存地址
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;//往外设写数据
DMA_InitStructure.DMA_BufferSize = 256;//缓冲区大小
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//外设地址不递增
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//内存地址递增
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;//传输单位大小
DMA_InitStructure.DMA_MemoryDataSize = DMA_PeripheralDataSize_Byte;//传输单位大小
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;//循环模式
DMA_InitStructure.DMA_Priority = DMA_Priority_High;//优先级高
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;//不使用内存到内存传输
DMA_Init(DMA2_Channel4, &DMA_InitStructure);

/* Enable DMA1 Channel1 */
DMA_Cmd(DMA2_Channel4, ENABLE);//使能DMA2通道4
}

正弦值数组：
uc8 SinTab[256] = {0x7F,0x82,0x85,0x88,0x8B,0x8F,0x92,0x95,0x98,0x9B,0x9E,0xA1,0xA4,0xA7,0xAA,0xAD,
0xB0,0xB3,0xB6,0xB8,0xBB,0xBE,0xC1,0xC3,0xC6,0xC8,0xCB,0xCD,0xD0,0xD2,0xD5,0xD7,
0xD9,0xDB,0xDD,0xE0,0xE2,0xE4,0xE5,0xE7,0xE9,0xEB,0xEC,0xEE,0xEF,0xF1,0xF2,0xF4,
0xF5,0xF6,0xF7,0xF8,0xF9,0xFA,0xFB,0xFB,0xFC,0xFD,0xFD,0xFE,0xFE,0xFE,0xFE,0xFE,
0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFD,0xFD,0xFC,0xFB,0xFB,0xFA,0xF9,0xF8,0xF7,0xF6,
0xF5,0xF4,0xF2,0xF1,0xEF,0xEE,0xEC,0xEB,0xE9,0xE7,0xE5,0xE4,0xE2,0xE0,0xDD,0xDB,
0xD9,0xD7,0xD5,0xD2,0xD0,0xCD,0xCB,0xC8,0xC6,0xC3,0xC1,0xBE,0xBB,0xB8,0xB6,0xB3,
0xB0,0xAD,0xAA,0xA7,0xA4,0xA1,0x9E,0x9B,0x98,0x95,0x92,0x8F,0x8B,0x88,0x85,0x82,
0x7F,0x7C,0x79,0x76,0x73,0x6F,0x6C,0x69,0x66,0x63,0x60,0x5D,0x5A,0x57,0x54,0x51,
0x4E,0x4B,0x48,0x46,0x43,0x40,0x3D,0x3B,0x38,0x36,0x33,0x31,0x2E,0x2C,0x29,0x27,
0x25,0x23,0x21,0x1E,0x1C,0x1A,0x19,0x17,0x15,0x13,0x12,0x10,0x0F,0x0D,0x0C,0x0A,
0x09,0x08,0x07,0x06,0x05,0x04,0x03,0x03,0x02,0x01,0x01,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x01,0x02,0x03,0x03,0x04,0x05,0x06,0x07,0x08,
0x09,0x0A,0x0C,0x0D,0x0F,0x10,0x12,0x13,0x15,0x17,0x19,0x1A,0x1C,0x1E,0x21,0x23,
0x25,0x27,0x29,0x2C,0x2E,0x31,0x33,0x36,0x38,0x3B,0x3D,0x40,0x43,0x46,0x48,0x4B,
0x4E,0x51,0x54,0x57,0x5A,0x5D,0x60,0x63,0x66,0x69,0x6C,0x6F,0x73,0x76,0x79,0x7C};

main调用：
TIM7_Int_Init(77, 71);

出不来波形，坐等大侠。。。。