stm32f407的pe5的tim9通过dma输出脉冲

要实现PE5的TIM9通过DMA输出脉冲，可以按照以下步骤进行：

1. 配置TIM9的输出模式为PWM模式，并设置周期和占空比；
2. 配置DMA通道，选择TIM9的CCR寄存器作为数据源，设置目的地址为PE5的GPIO寄存器；
3. 启动DMA传输，使TIM9的CCR寄存器的值不断传输到PE5的GPIO寄存器中。

具体实现代码如下：

// 定义DMA传输缓存区
uint32_t dma_buffer;

// 配置TIM9的PWM输出模式
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

TIM_TimeBaseStructure.TIM_Period = 999;  // 设置周期为1000
TIM_TimeBaseStructure.TIM_Prescaler = 83;  // 设置预分频为84
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM9, &TIM_TimeBaseStructure);

TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_Pulse = 500;  // 设置占空比为50%
TIM_OC1Init(TIM9, &TIM_OCInitStructure);
TIM_Cmd(TIM9, ENABLE);

// 配置DMA通道
DMA_InitTypeDef DMA_InitStructure;

DMA_StructInit(&DMA_InitStructure);
DMA_InitStructure.DMA_Channel = DMA_Channel_3;
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&dma_buffer;
DMA_InitStructure.DMA_BufferSize = 1;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&GPIOE->ODR;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
DMA_Init(DMA1_Stream2, &DMA_InitStructure);

// 启动DMA传输
DMA_Cmd(DMA1_Stream2, ENABLE);

在上述代码中，TIM9的输出模式被配置为PWM1模式，周期为1000，占空比为50%。同时，DMA通道被配置为从TIM9的CCR寄存器读取数据，并将数据传输到PE5的GPIO寄存器中。最后，启动DMA传输即可让TIM9通过DMA输出脉冲。