fpga和stm32通信代码

FPGA和STM32可以通过多种接口进行通信，例如SPI、I2C、UART等。下面以SPI接口为例，介绍如何在STM32和FPGA之间进行通信。

在STM32上，需要通过HAL库和SPI驱动程序进行配置和使用SPI接口。以下是一个简单的STM32和FPGA之间SPI通信的代码示例：

#include "stm32f4xx_hal.h"

SPI_HandleTypeDef hspi1;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_SPI1_Init(void);

int main(void)
{
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_SPI1_Init();

  while (1)
  {
    uint8_t tx_data = 0x55;
    uint8_t rx_data;

    HAL_SPI_TransmitReceive(&hspi1, &tx_data, &rx_data, 1, 100);
    // 发送一个字节的数据并接收一个字节的数据
  }
}

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 8;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1
                              |RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_SPI1_Init(void)
{
  hspi1.Instance = SPI1;
  hspi1.Init.Mode = SPI_MODE_MASTER; // 主设备
  hspi1.Init.Direction = SPI_DIRECTION_2LINES; // 双向传输
  hspi1.Init.DataSize = SPI_DATASIZE_8BIT; // 数据位宽为8位
  hspi1.Init.CLKPolarity = SPI_POLARITY_LOW; // 时钟极性为低
  hspi1.Init.CLKPhase = SPI_PHASE_1EDGE; // 时钟相位为第一边沿
  hspi1.Init.NSS = SPI_NSS_SOFT; // 软件片选
  hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_256; // 时钟分频系数为256
  hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB; // MSB优先
  hspi1.Init.TIMode = SPI_TIMODE_DISABLE; // 不使用 TI 模式
  hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE; // 不使用 CRC 校验

  if (HAL_SPI_Init(&hspi1) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOC_CLK_ENABLE();

  GPIO_InitStruct.Pin = GPIO_PIN_5 | GPIO_PIN_6 | GPIO_PIN_7;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
  GPIO_InitStruct.Alternate = GPIO_AF5_SPI1;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  GPIO_InitStruct.Pin = GPIO_PIN_4;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP; // 片选引脚作为输出
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
  HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
}

在FPGA上，需要根据所使用的开发板和FPGA型号，进行相应的配置和编程。以下是一个简单的FPGA SPI接口的代码示例：

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NUMERIC_STD.ALL;

entity spi_interface is
  port (
    clk : in std_logic;
    reset : in std_logic;
    mosi : in std_logic;
    miso : out std_logic;
    cs : out std_logic
  );
end spi_interface;

architecture Behavioral of spi_interface is
  signal sclk : std_logic;
  signal ssel : std_logic;
  signal tx_data : std_logic_vector(7 downto 0);
  signal rx_data : std_logic_vector(7 downto 0);
  signal data_valid : std_logic := '0';

begin
  process(clk, reset)
  begin
    if reset = '1' then
      sclk <= '0';
      ssel <= '1';
    elsif rising_edge(clk) then
      if ssel = '0' then
        if tx_data'length > 0 then
          mosi <= tx_data(0);
          tx_data <= tx_data(1 to tx_data'high);
          sclk <= not sclk;
        else
          tx_data <= (others => '0');
          rx_data <= (others => '0');
          data_valid <= '0';
          ssel <= '1';
        end if;
      else
        mosi <= 'Z';
        data_valid <= '0';
        sclk <= '0';
        if cs = '0' then
          ssel <= '0';
          rx_data <= (others => 'Z');
        end if;
      end if;
    end if;
  end process;

  miso <= rx_data(0);

  process(clk)
  begin
    if rising_edge(clk) then
      if cs = '0' and ssel = '0' then
        rx_data <= miso & rx_data(7 downto 1);
        if sclk = '1' then
          data_valid <= '1';
        end if;
      end if;
    end if;
  end process;

end Behavioral;

以上是一个简单的FPGA SPI接口的代码示例，需要根据实际情况进行修改和调试。在使用FPGA通信时，需要注意时序和信号电平的匹配，以确保通信正常。