GD32F450上升沿采样_定时器捕获外部上升沿信号,DMA读取GPIO口数据的问题

你好，关于GD32F450的上升沿采样问题，可以使用定时器捕获外部上升沿信号。具体步骤如下：

1. 配置定时器为捕获模式，选择外部输入时钟源和捕获通道。

2. 配置GPIO口为输入模式，用于接收外部信号。

3. 在定时器中断处理函数中，读取捕获寄存器的值，即可获取到上升沿的时间戳。

4. 可以使用DMA读取GPIO口数据，将数据传输到指定的内存地址。

以下是示例代码：

#include "gd32f4xx.h"

#define GPIO_PORT    GPIOA
#define GPIO_PIN     GPIO_PIN_0

uint16_t capture_value = 0;
uint8_t data_buffer[1024] = {0};

void timer_capture_init(void)
{
    /* enable the TIMER0 clock */
    rcu_periph_clock_enable(RCU_TIMER0);
    
    /* TIMER0 configuration */
    timer_oc_parameter_struct timer_ocinitpara;
    timer_parameter_struct timer_initpara;
    
    timer_deinit(TIMER0);   /* reset the TIMER0 registers */
    timer_struct_para_init(&timer_initpara);
    
    timer_initpara.prescaler         = 0;                       /* no prescaler */
    timer_initpara.alignedmode       = TIMER_COUNTER_EDGE;      /* edge-aligned mode */
    timer_initpara.counterdirection = TIMER_COUNTER_UP;         /* up-counting */
    timer_initpara.period            = 0xFFFF;                  /* maximum period value */
    timer_initpara.clockdivision     = TIMER_CKDIV_DIV1;
    timer_init(TIMER0, &timer_initpara);
    
    /* configure the TIMER0 channel 0 to capture the external signal */
    timer_oc_struct_para_init(&timer_ocinitpara);
    timer_ocinitpara.ocpolarity     = TIMER_OC_POLARITY_RISING; /* rising edge */
    timer_ocinitpara.outputstate    = TIMER_CCX_ENABLE;
    timer_channel_output_config(TIMER0, TIMER_CH_0, &timer_ocinitpara);
    timer_input_capture_config(TIMER0, TIMER_CH_0);
    
    /* enable the TIMER0 interrupt */
    timer_interrupt_enable(TIMER0, TIMER_INT_CH0);
    nvic_irq_enable(TIMER0_IRQn, 0, 0);
    
    /* enable TIMER0 */
    timer_enable(TIMER0);
}

void gpio_input_init(void)
{
    /* enable the GPIOA clock */
    rcu_periph_clock_enable(RCU_GPIOA);
    
    /* configure PA0 as input */
    gpio_mode_set(GPIO_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE, GPIO_PIN);
}

void dma_transfer_init(void)
{
    /* enable the DMA clock */
    rcu_periph_clock_enable(RCU_DMA0);
    
    /* DMA configuration */
    dma_parameter_struct dma_initpara;
    dma_struct_para_init(&dma_initpara);
    
    dma_deinit(DMA0, DMA_CH0);
    
    dma_initpara.direction     = DMA_PERIPHERAL_TO_MEMORY;  /* peripheral to memory */
    dma_initpara.periph_addr   = (uint32_t)&GPIO_PORT->IDR;  /* peripheral address */
    dma_initpara.memory_addr   = (uint32_t)data_buffer;     /* memory address */
    dma_initpara.number        = 1024;                      /* transfer number */
    dma_initpara.periph_inc    = DMA_PERIPH_INCREASE_DISABLE;
    dma_initpara.memory_inc    = DMA_MEMORY_INCREASE_ENABLE; /* memory increase */
    dma_initpara.periph_width  = DMA_PERIPHERAL_WIDTH_16BIT; /* 16-bit width */
    dma_initpara.memory_width  = DMA_MEMORY_WIDTH_8BIT;     /* 8-bit width */
    dma_initpara.circular     = DMA_CIRCULAR_ENABLE;        /* circular mode */
    dma_initpara.priority     = DMA_PRIORITY_HIGH;          /* high priority */
    dma_init(DMA0, DMA_CH0, &dma_initpara);
    
    /* enable DMA channel */
    dma_channel_enable(DMA0, DMA_CH0);
}

void TIMER0_IRQHandler(void)
{
    if(RESET != timer_interrupt_flag_get(TIMER0, TIMER_INT_CH0))
    {
        capture_value = timer_channel_capture_value_register(TIMER0, TIMER_CH_0);
        
        /* clear the interrupt flag */
        timer_interrupt_flag_clear(TIMER0, TIMER_INT_CH0);
    }
}

int main(void)
{
    timer_capture_init();
    gpio_input_init();
    dma_transfer_init();
    
    while(1)
    {
        /* wait for DMA transfer complete */
        while(!dma_flag_get(DMA0, DMA_CH0, DMA_FLAG_FTF));
        
        /* do something with data_buffer */
        
        /* clear the transfer complete flag */
        dma_flag_clear(DMA0, DMA_CH0, DMA_FLAG_FTF);
    }
    
    return 0;
}

注意，以上代码仅供参考，具体实现方式可能因为应用场景不同而略有差异。