stm32实现软件spi

Driver_SPI.c

#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

#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