stm32实现软件spi

Driver_SPI.c

c 复制代码

#include "Driver_SPI.h"

void Driver_SPI_Init(void)
{
    /* 1. 开启GPIO时钟 PA和PC*/
    RCC->APB2ENR |= (RCC_APB2ENR_IOPCEN | RCC_APB2ENR_IOPAEN);

    /* 2. 设置引脚的工作模式 */
    /* 2.1 cs: 推挽输出 PC13*  CNF=00 MODE=11 */
    GPIOC->CRH &= ~GPIO_CRH_CNF13;
    GPIOC->CRH |= GPIO_CRH_MODE13;
    /* 2.2 sck: 推挽输出 PA5*/
    /* 2.3 mosi: 推挽输出 PA7*/
    GPIOA->CRL &= ~(GPIO_CRL_CNF5 | GPIO_CRL_CNF7);
    GPIOA->CRL |= (GPIO_CRL_MODE5 | GPIO_CRL_MODE7);
    /* 2.4 miso: 浮空输入 PA6  CNF=01 MODE=00*/
    GPIOA->CRL &= ~(GPIO_CRL_CNF6_1 | GPIO_CRL_MODE6);
    GPIOA->CRL |= GPIO_CRL_CNF6_0;

    /* 3. spi的模式0  sck空闲状态是 0   */
    SCK_LOW;
    /* 4. 片选默认不选中 */
    CS_HIGH;

    /* 5. 延时 */
    SPI_DELAY;
}
void Driver_SPI_Start(void)
{
    CS_LOW;
    // SPI_DELAY;
}

void Driver_SPI_Stop(void)
{
    CS_HIGH;
    // SPI_DELAY;
}

uint8_t Driver_SPI_SwapByte(uint8_t byte)
{
    uint8_t rByte = 0x00;
    for (uint8_t i = 0; i < 8; i++)
    {
        //(byte & 0x80) ? MOSI_HIGH : MOSI_LOW;
        /* 1. 先把数据放入到MOSI上 */
        if (byte & 0x80)
        {
            MOSI_HIGH;
        }
        else
        {
            MOSI_LOW;
        }
        byte <<= 1;
        // SPI_DELAY;
        /* 2. 拉高时钟 (第一个跳变)*/
        SCK_HIGH;
        // SPI_DELAY;
        /* 3. 读取miso  (第一个跳变采样)*/
        rByte <<= 1;
        // MISO_READ ? rByte|= 0x01 : rByte;
        if (MISO_READ)
        {
            rByte |= 0x01;
        }
        /* 4. 拉低时钟 */
        SCK_LOW;
        // SPI_DELAY;
    }
    return rByte;
}

Driver_SPI.h

c 复制代码

#ifndef __DRIVER_SPI_H
#define __DRIVER_SPI_H

#include "stm32f10x.h"
#include "Delay.h"



#define CS_HIGH (GPIOC->ODR |= GPIO_ODR_ODR13)
#define CS_LOW (GPIOC->ODR &= ~GPIO_ODR_ODR13)

#define SCK_HIGH (GPIOA->ODR |= GPIO_ODR_ODR5)
#define SCK_LOW (GPIOA->ODR &= ~GPIO_ODR_ODR5)

#define MOSI_HIGH (GPIOA->ODR |= GPIO_ODR_ODR7)
#define MOSI_LOW (GPIOA->ODR &= ~GPIO_ODR_ODR7)


#define MISO_READ (GPIOA->IDR & GPIO_IDR_IDR6)

#define SPI_DELAY Delay_us(5)

void Driver_SPI_Init(void);

void Driver_SPI_Start(void);

void Driver_SPI_Stop(void);

uint8_t Driver_SPI_SwapByte(uint8_t byte);

#endif