GD32F303 SPI DMA 参考程序

以下是一个基本的SPI DMA参考程序，使用GD32F303 MCU和ST固件库：

#include "gd32f30x.h"

#define SPIx                           SPI1
#define SPIx_CLK                       RCU_SPI1
#define SPIx_APBxClock                 RCU_APB2
#define SPIx_GPIO_APBxClock            RCU_GPIOA
#define SPIx_GPIO                      GPIOA
#define SPIx_PIN_NSS                   GPIO_PIN_4
#define SPIx_PIN_SCK                   GPIO_PIN_5
#define SPIx_PIN_MISO                  GPIO_PIN_6
#define SPIx_PIN_MOSI                  GPIO_PIN_7
#define SPIx_CS_LOW()                  gpio_bit_reset(SPIx_GPIO, SPIx_PIN_NSS)
#define SPIx_CS_HIGH()                 gpio_bit_set(SPIx_GPIO, SPIx_PIN_NSS)

#define DMAx_CLK                       RCU_DMA0
#define DMAx_CHANNEL                   DMA_CH2
#define DMAx_CHANNEL_IRQ               DMA0_Channel2_IRQn
#define DMAx_CHANNEL_IRQHANDLER         DMA0_Channel2_IRQHandler

#define BUFFER_SIZE                    256

uint8_t send_buffer[BUFFER_SIZE];
uint8_t receive_buffer[BUFFER_SIZE];

void spi_gpio_init(void)
{
    /* enable SPI GPIO clock */
    rcu_periph_clock_enable(SPIx_GPIO_APBxClock);
  
    /* configure SPI NSS/CLK/MISO/MOSI GPIO port */
    gpio_init(SPIx_GPIO, GPIO_MODE_OUT_PP, GPIO_OSPEED_50MHZ, SPIx_PIN_NSS);
    gpio_init(SPIx_GPIO, GPIO_MODE_AF_PP, GPIO_OSPEED_50MHZ, SPIx_PIN_SCK);
    gpio_init(SPIx_GPIO, GPIO_MODE_AF_PP, GPIO_OSPEED_50MHZ, SPIx_PIN_MISO);
    gpio_init(SPIx_GPIO, GPIO_MODE_AF_PP, GPIO_OSPEED_50MHZ, SPIx_PIN_MOSI);
  
    /* SPI NSS output high */
    gpio_bit_set(SPIx_GPIO, SPIx_PIN_NSS);
}

void spi_dma_init(void)
{
    /* enable DMA clock */
    rcu_periph_clock_enable(DMAx_CLK);

    /* initialize DMA channel */
    dma_deinit(DMAx_CHANNEL);

    dma_struct_para_init(&dma_init_struct);

    /* DMA channel configuration */
    dma_init_struct.direction = DMA_MEMORY_TO_PERIPHERAL;
    dma_init_struct.memory_addr = (uint32_t)send_buffer;
    dma_init_struct.memory_inc = DMA_MEMORY_INC_ENABLE;
    dma_init_struct.memory_width = DMA_MEMORY_WIDTH_8BIT;
    dma_init_struct.number = BUFFER_SIZE;
    dma_init_struct.periph_addr = (uint32_t)&SPIx->DR;
    dma_init_struct.periph_inc = DMA_PERIPH_INC_DISABLE;
    dma_init_struct.periph_width = DMA_PERIPH_WIDTH_8BIT;
    dma_init_struct.priority = DMA_PRIORITY_HIGH;

    dma_init(DMAx_CHANNEL, dma_init_struct);

    /* enable DMA channel transfer complete interrupt */
    dma_interrupt_enable(DMAx_CHANNEL, DMA_INT_FTF);
    nvic_irq_enable(DMAx_CHANNEL_IRQ, 0, 0);
}

void spi_init(void)
{
    spi_parameter_struct spi_init_struct;

    /* enable SPI clock */
    rcu_periph_clock_enable(SPIx_CLK);

    /* SPI parameter configuration */
    spi_init_struct.trans_mode = SPI_TRANSMODE_FULLDUPLEX;
    spi_init_struct.device_mode = SPI_MASTER;
    spi_init_struct.frame_size = SPI_FRAMESIZE_8BIT;
    spi_init_struct.clock_polarity_phase = SPI_CK_PL_LOW_PH_1EDGE;
    spi_init_struct.nss = SPI_NSS_SOFT;
    spi_init_struct.prescale = SPI_PSC_8;
    spi_init_struct.endian = SPI_ENDIAN_MSB;
    spi_init(SPIx, &spi_init_struct);

    /* enable SPI DMA */
    spi_dma_enable(SPIx, SPI_DMA_TRANSMIT);
}

void dma_transfer_complete_handler(void)
{
    /* disable DMA channel */
    dma_channel_disable(DMAx_CHANNEL);

    /* wait until SPI is not busy */
    while (SET == spi_i2s_flag_get(SPIx, SPI_FLAG_BUSY));

    /* receive data from SPI */
    for (uint16_t i = 0; i < BUFFER_SIZE; i++)
    {
        /* wait until receive buffer is not empty */
        while (RESET == spi_i2s_flag_get(SPIx, SPI_FLAG_RNE));
        receive_buffer[i] = spi_i2s_data_receive(SPIx);
    }

    /* do something with received data */

    /* re-enable DMA channel */
    dma_channel_enable(DMAx_CHANNEL);
}

int main(void)
{
    /* initialize SPI GPIO and DMA */
    spi_gpio_init();
    spi_dma_init();

    /* initialize SPI */
    spi_init();

    /* fill send buffer with data */
    for (uint16_t i = 0; i < BUFFER_SIZE; i++)
    {
        send_buffer[i] = i;
    }

    /* enable DMA channel */
    dma_channel_enable(DMAx_CHANNEL);

    while (1)
    {
        /* do something */
    }
}

/* DMA interrupt handler */
void DMAx_CHANNEL_IRQHANDLER(void)
{
    if (dma_interrupt_flag_get(DMAx_CHANNEL, DMA_INT_FLAG_FTF))
    {
        dma_interrupt_flag_clear(DMAx_CHANNEL, DMA_INT_FLAG_FTF);
        dma_transfer_complete_handler();
    }
}

在这个例子中，我们使用SPI1作为主设备，使用DMA2通道2将数据发送到SPI，然后等待接收数据。在发送数据之前，我们填充了一个缓冲区，然后启用DMA通道并等待传输完成。一旦传输完成，我们从SPI接收数据，并将它们存储在另一个缓冲区中。在实际的应用程序中，您可以根据需要调整缓冲区的大小和填充数据的方式，以及对接收到的数据执行的操作。