STM32标准外设SPI通信SPL篇6

添加库函数

  • 打开 Manage Run-Time Environment
  • 选择Device->StdPeriph Drivers->SPI

SPI初始化

SPI宏定义

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#ifndef __SPI_FLASH_H
#define __SPI_FLASH_H

#include "stm32f10x.h"
#include <stdio.h>
/*SPI接口定义-开头****************************/
#define      FLASH_SPIx                        SPI1
#define      FLASH_SPI_APBxClock_FUN           RCC_APB2PeriphClockCmd
#define      FLASH_SPI_CLK                     RCC_APB2Periph_SPI1

//CS(NSS)引脚 片选选普通GPIO即可
#define      FLASH_SPI_CS_APBxClock_FUN        RCC_APB2PeriphClockCmd
#define      FLASH_SPI_CS_CLK                  RCC_APB2Periph_GPIOA
#define      FLASH_SPI_CS_PORT                 GPIOA
#define      FLASH_SPI_CS_PIN                  GPIO_Pin_4

//SCK引脚
#define      FLASH_SPI_SCK_APBxClock_FUN       RCC_APB2PeriphClockCmd
#define      FLASH_SPI_SCK_CLK                 RCC_APB2Periph_GPIOA
#define      FLASH_SPI_SCK_PORT                GPIOA
#define      FLASH_SPI_SCK_PIN                 GPIO_Pin_5
//MISO引脚
#define      FLASH_SPI_MISO_APBxClock_FUN      RCC_APB2PeriphClockCmd
#define      FLASH_SPI_MISO_CLK                RCC_APB2Periph_GPIOA
#define      FLASH_SPI_MISO_PORT               GPIOA
#define      FLASH_SPI_MISO_PIN                GPIO_Pin_6
//MOSI引脚
#define      FLASH_SPI_MOSI_APBxClock_FUN      RCC_APB2PeriphClockCmd
#define      FLASH_SPI_MOSI_CLK                RCC_APB2Periph_GPIOA
#define      FLASH_SPI_MOSI_PORT               GPIOA
#define      FLASH_SPI_MOSI_PIN                GPIO_Pin_7

#define  		SPI_FLASH_CS_LOW()     						GPIO_ResetBits( FLASH_SPI_CS_PORT, FLASH_SPI_CS_PIN )
#define  		SPI_FLASH_CS_HIGH()    						GPIO_SetBits( FLASH_SPI_CS_PORT, FLASH_SPI_CS_PIN )

/*等待超时时间*/
#define SPIT_FLAG_TIMEOUT         ((uint32_t)0x1000)
#endif

SPI初始化设置

使能外设时钟和IO初始化

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    GPIO_InitTypeDef GPIO_InitStructure;

    /* 使能SPI时钟 */
    FLASH_SPI_APBxClock_FUN ( FLASH_SPI_CLK, ENABLE );

    /* 使能SPI引脚相关的时钟 */
    FLASH_SPI_CS_APBxClock_FUN ( FLASH_SPI_CS_CLK|FLASH_SPI_SCK_CLK|
                                 FLASH_SPI_MISO_PIN|FLASH_SPI_MOSI_PIN, ENABLE );

    /* 配置SPI的 CS引脚，普通IO即可 */
    GPIO_InitStructure.GPIO_Pin = FLASH_SPI_CS_PIN;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_Init(FLASH_SPI_CS_PORT, &GPIO_InitStructure);

    /* 配置SPI的 SCK引脚*/
    GPIO_InitStructure.GPIO_Pin = FLASH_SPI_SCK_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(FLASH_SPI_SCK_PORT, &GPIO_InitStructure);

    /* 配置SPI的 MISO引脚*/
    GPIO_InitStructure.GPIO_Pin = FLASH_SPI_MISO_PIN;
    GPIO_Init(FLASH_SPI_MISO_PORT, &GPIO_InitStructure);

    /* 配置SPI的 MOSI引脚*/
    GPIO_InitStructure.GPIO_Pin = FLASH_SPI_MOSI_PIN;
    GPIO_Init(FLASH_SPI_MOSI_PORT, &GPIO_InitStructure);

    /* 停止信号 FLASH: CS引脚高电平*/
    SPI_FLASH_CS_HIGH();

SPI初始化

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    /* SPI 模式配置 */
    SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
    SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
    SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
    SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
    SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
    SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
    SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;
    SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
    SPI_InitStructure.SPI_CRCPolynomial = 7;
    SPI_Init(FLASH_SPIx , &SPI_InitStructure);

    /* 使能 SPI  */
    SPI_Cmd(FLASH_SPIx , ENABLE);

SPI结构体分析

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/** 
  * @brief  SPI Init structure definition  
  */

typedef struct
{
  uint16_t SPI_Direction;           /*!< Specifies the SPI unidirectional or bidirectional data mode.
                                         This parameter can be a value of @ref SPI_data_direction */

  uint16_t SPI_Mode;                /*!< Specifies the SPI operating mode.
                                         This parameter can be a value of @ref SPI_mode */

  uint16_t SPI_DataSize;            /*!< Specifies the SPI data size.
                                         This parameter can be a value of @ref SPI_data_size */

  uint16_t SPI_CPOL;                /*!< Specifies the serial clock steady state.
                                         This parameter can be a value of @ref SPI_Clock_Polarity */

  uint16_t SPI_CPHA;                /*!< Specifies the clock active edge for the bit capture.
                                         This parameter can be a value of @ref SPI_Clock_Phase */

  uint16_t SPI_NSS;                 /*!< Specifies whether the NSS signal is managed by
                                         hardware (NSS pin) or by software using the SSI bit.
                                         This parameter can be a value of @ref SPI_Slave_Select_management */
 
  uint16_t SPI_BaudRatePrescaler;   /*!< Specifies the Baud Rate prescaler value which will be
                                         used to configure the transmit and receive SCK clock.
                                         This parameter can be a value of @ref SPI_BaudRate_Prescaler.
                                         @note The communication clock is derived from the master
                                               clock. The slave clock does not need to be set. */

  uint16_t SPI_FirstBit;            /*!< Specifies whether data transfers start from MSB or LSB bit.
                                         This parameter can be a value of @ref SPI_MSB_LSB_transmission */

  uint16_t SPI_CRCPolynomial;       /*!< Specifies the polynomial used for the CRC calculation. */
}SPI_InitTypeDef;
  • SPI单双向模式SPI_Direction
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/** @defgroup SPI_data_direction 
  * @{
  */
  
#define SPI_Direction_2Lines_FullDuplex ((uint16_t)0x0000) //双线全双工
#define SPI_Direction_2Lines_RxOnly     ((uint16_t)0x0400) //双线只接收
#define SPI_Direction_1Line_Rx          ((uint16_t)0x8000) //单线只接收
#define SPI_Direction_1Line_Tx          ((uint16_t)0xC000) //单线只发送
  • 主从机模式SPI_Mode
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/** @defgroup SPI_mode 
  * @{
  */

#define SPI_Mode_Master                 ((uint16_t)0x0104) //主机模式
#define SPI_Mode_Slave                  ((uint16_t)0x0000) //从机模式
  • 数据帧长度 SPI_DataSize
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/** @defgroup SPI_data_size 
  * @{
  */

#define SPI_DataSize_16b                ((uint16_t)0x0800) //16位
#define SPI_DataSize_8b                 ((uint16_t)0x0000) //8位
  • 时钟极性SPI_CPOL
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/** @defgroup SPI_Clock_Polarity 
  * @{
  */

#define SPI_CPOL_Low                    ((uint16_t)0x0000) //低电平
#define SPI_CPOL_High                   ((uint16_t)0x0002) //高电平
  • 时钟相位SPI_CPHA
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/** @defgroup SPI_Clock_Phase 
  * @{
  */

#define SPI_CPHA_1Edge                  ((uint16_t)0x0000) //在SCK 的奇数边沿采集数据
#define SPI_CPHA_2Edge                  ((uint16_t)0x0001) //在SCK 的偶数边沿采集数据
SPI模式 CPOL CPHA 空闲时SCk时钟 采样时刻
0 0 0 低电平 奇数边沿
1 0 1 低电平 偶数边沿
2 1 0 高电平 奇数边沿
3 1 1 高电平 偶数边沿
  • 片选信号SPI_NSS
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/** @defgroup SPI_Slave_Select_management 
  * @{
  */

#define SPI_NSS_Soft                    ((uint16_t)0x0200) //软件模式
#define SPI_NSS_Hard                    ((uint16_t)0x0000) //硬件模式
  • 波特率分频因子SPI_BaudRatePrescaler
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/** @defgroup SPI_BaudRate_Prescaler 
  * @{
  */

#define SPI_BaudRatePrescaler_2         ((uint16_t)0x0000)
#define SPI_BaudRatePrescaler_4         ((uint16_t)0x0008)
#define SPI_BaudRatePrescaler_8         ((uint16_t)0x0010)
#define SPI_BaudRatePrescaler_16        ((uint16_t)0x0018)
#define SPI_BaudRatePrescaler_32        ((uint16_t)0x0020)
#define SPI_BaudRatePrescaler_64        ((uint16_t)0x0028)
#define SPI_BaudRatePrescaler_128       ((uint16_t)0x0030)
#define SPI_BaudRatePrescaler_256       ((uint16_t)0x0038)
BR[0:2] 分频结果(SCK 频率)
000 fpclk/2
001 fpclk/4
010 fpclk/8
011 fpclk/16
100 fpclk/32
101 fpclk/64
110 fpclk/128
111 fpclk/256
  • 高低位先行选择SPI_FirstBit
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/** @defgroup SPI_MSB_LSB_transmission 
  * @{
  */

#define SPI_FirstBit_MSB                ((uint16_t)0x0000) //高位先行
#define SPI_FirstBit_LSB                ((uint16_t)0x0080) //低位先行
  • CRC校验SPI_CRCPolynomial

SPI发送数据

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static __IO uint32_t  SPITimeout;
/**
 * @brief  使用SPI发送一个字节的数据
 * @param  byte：要发送的数据
 * @retval 返回接收到的数据
 */
uint8_t SPI_FLASH_SendByte(uint8_t byte)
{
    SPITimeout = SPIT_FLAG_TIMEOUT;
    /* 等待发送缓冲区为空，TXE事件 */
    while (SPI_I2S_GetFlagStatus(FLASH_SPIx , SPI_I2S_FLAG_TXE) == RESET)
    {
        if((SPITimeout--) == 0) return 0;
    }

    /* 写入数据寄存器，把要写入的数据写入发送缓冲区 */
    SPI_I2S_SendData(FLASH_SPIx , byte);

    SPITimeout = SPIT_FLAG_TIMEOUT;
    /* 等待接收缓冲区非空，RXNE事件 */
    while (SPI_I2S_GetFlagStatus(FLASH_SPIx , SPI_I2S_FLAG_RXNE) == RESET)
    {
        if((SPITimeout--) == 0) return 0;
    }

    /* 读取数据寄存器，获取接收缓冲区数据 */
    return SPI_I2S_ReceiveData(FLASH_SPIx );
}