#include "stm32f10x.h"
#include "DAC.h"

void GPIO_Config(void)
{
        GPIO_InitTypeDef GPIO_InitStructure;

        RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOA, ENABLE);  

        GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_5;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
        GPIO_Init(GPIOA, &GPIO_InitStructure);               
}

void DAC_Config(void)
{
        DAC_InitTypeDef     DAC_InitStructure;                           //定义结构体
                                                                                                          
        RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);//开启DAC时钟

        /* DAC channel1 Configuration */
        DAC_StructInit(&DAC_InitStructure);
        DAC_InitStructure.DAC_Trigger = DAC_Trigger_T6_TRGO;         //指定DAC1的触发定时器
        DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
        DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Disable;
        DAC_Init(DAC_Channel_2, &DAC_InitStructure);
       
        /* Enable DAC Channel2: Once the DAC channel2 is enabled, PA.05 is automatically connected to the DAC converter. */
        DAC_Cmd(DAC_Channel_2, ENABLE);
       
        /* Enable DMA for DAC Channel2 */
        DAC_DMACmd(DAC_Channel_2, ENABLE);
}


#include "stm32f10x.h"
#include "TIM.h"

void TIM_Config(void)
{
        TIM_TimeBaseInitTypeDef    TIM_TimeBaseStructure;//定义TIM结构体

        RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM6, ENABLE);//打开TIM的时钟

        TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
        TIM_TimeBaseStructure.TIM_Period = Sin_Out_4KHz;   //正弦波1频率设置         
        TIM_TimeBaseStructure.TIM_Prescaler = 0x0;      
        TIM_TimeBaseStructure.TIM_ClockDivision = 0x0;   
        TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  
        TIM_TimeBaseInit(TIM6, &TIM_TimeBaseStructure);
       

        TIM_SelectOutputTrigger(TIM6, TIM_TRGOSource_Update);

        /* TIM2 enable counter */
        TIM_Cmd(TIM6, ENABLE);
}



#include "stm32f10x.h"
#include "DMA.h"

const uint16_t Sine12bit[258] = {
2048, 2098, 2148, 2198, 2248, 2298, 2348, 2398, 2447, 2496,
2545, 2594, 2642, 2690, 2737, 2785, 2831, 2877, 2923, 2968,
3013, 3057, 3100, 3143, 3185, 3227, 3267, 3307, 3347, 3385,
3423, 3460, 3496, 3531, 3565, 3598, 3631, 3662, 3692, 3722,
3750, 3778, 3804, 3829, 3854, 3877, 3899, 3920, 3940, 3958,
3976, 3992, 4007, 4021, 4034, 4046, 4056, 4065, 4073, 4080,
4086, 4090, 4093, 4095, 4095, 4095, 4093, 4090, 4086, 4080,
4073, 4065, 4056, 4046, 4034, 4021, 4007, 3992, 3976, 3958,
3940, 3920, 3899, 3877, 3854, 3829, 3804, 3778, 3750, 3722,
3692, 3662, 3631, 3598, 3565, 3531, 3496, 3460, 3423, 3385,
3347, 3307, 3267, 3227, 3185, 3143, 3100, 3057, 3013, 2968,
2923, 2877, 2831, 2785, 2737, 2690, 2642, 2594, 2545, 2496,
2447, 2398, 2348, 2298, 2248, 2198, 2148, 2098, 2047, 1997,
1947, 1897, 1847, 1797, 1747, 1697, 1648, 1599, 1550, 1501,
1453, 1405, 1358, 1310, 1264, 1218, 1172, 1127, 1082, 1038,
995, 952, 910, 868, 828, 788, 748, 710, 672, 635,
599, 564, 530, 497, 464, 433, 403, 373, 345, 317,
291, 266, 241, 218, 196, 175, 155, 137, 119, 103,
88, 74, 61, 49, 39, 30, 22, 15, 9, 5,
2, 0, 0, 0, 2, 5, 9, 15, 22, 30,
39, 49, 61, 74, 88, 103, 119, 137, 155, 175,
196, 218, 241, 266, 291, 317, 345, 373, 403, 433,
464, 497, 530, 564, 599, 635, 672, 710, 748, 788,
828, 868, 910, 952, 995, 1038, 1082, 1127, 1172, 1218,
1264, 1310, 1358, 1405, 1453, 1501, 1550, 1599, 1648, 1697,
1747, 1797, 1847, 1897, 1947, 1997 };

void DMA_Config(void)
{
        DMA_InitTypeDef            DMA_InitStructure;
       
        RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE);

        /* DMA2 channel2 configuration */
        DMA_DeInit(DMA2_Channel4);
        DMA_InitStructure.DMA_PeripheralBaseAddr = DAC_DHR12R2; //指定DMA2通道3的目标地址为DAC1_DHR12R1
        DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&Sine12bit;        //指定DMA的源地址为数组Sine12bit
        DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
        DMA_InitStructure.DMA_BufferSize = 256;
        DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
        DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
        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_VeryHigh;
        DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
        DMA_Init(DMA2_Channel4, &DMA_InitStructure);
       
        /* Enable DMA2 Channel2 */
        DMA_Cmd(DMA2_Channel4, ENABLE);
}



DAC是通过定时器触发的，那么定时器是如何控制输出正弦波的频率的呢？定时器溢出周期与正弦波周期有什么关系？求详细解答