STM32 SPI SLAVE

一般使用SPI都用MASTER,但是用SLAVE没有用过.参考了ST的例子,发现不能满足自己的使用.于是,自己修改了一下.

初始化配置SPI

/**

  ******************************************************************************

  * @file    app.c

  * @author  MCD Application Team

  * @version V1.1.0

  * @date    19-March-2012

  * @brief   This file provides all the Application firmware functions.

  ******************************************************************************

  * @attention

  *

  *

© COPYRIGHT 2012 STMicroelectronics

  *

  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");

  * You may not use this file except in compliance with the License.

  * You may obtain a copy of the License at:

  *

  *        http://www.st.com/software_license_agreement_liberty_v2

  *

  * Unless required by applicable law or agreed to in writing, software 

  * distributed under the License is distributed on an "AS IS" BASIS, 

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  *

  ******************************************************************************

  */ 

/* Includes ------------------------------------------------------------------*/ 

#include "usbd_cdc_core.h"

#include "usbd_usr.h"

#include "usb_conf.h"

#include "usbd_desc.h"

#define RECV_SIZE (1024 * 16)

u8 g_cbRecvBuffer[RECV_SIZE] = {0};

 SPI_InitTypeDef  SPI_InitStructure;

RECV_STRUCT g_sRecvInfo = {0};

/**

  * @brief  Configures the SPI Peripheral.

  * @param  None

  * @retval None

  */

static void SPI_Config(void)

{

  GPIO_InitTypeDef GPIO_InitStructure;

  NVIC_InitTypeDef NVIC_InitStructure;

  /* Peripheral Clock Enable -------------------------------------------------*/

  /* Enable the SPI clock */

  SPIx_CLK_INIT(SPIx_CLK, ENABLE);

  /* Enable GPIO clocks */

  RCC_AHB1PeriphClockCmd(SPIx_SCK_GPIO_CLK | SPIx_MISO_GPIO_CLK | SPIx_MOSI_GPIO_CLK, ENABLE);

  /* SPI GPIO Configuration --------------------------------------------------*/

  /* GPIO Deinitialisation */

  GPIO_DeInit(SPIx_SCK_GPIO_PORT);

  GPIO_DeInit(SPIx_MISO_GPIO_PORT);

  GPIO_DeInit(SPIx_MOSI_GPIO_PORT);

  /* Connect SPI pins to AF5 */  

  GPIO_PinAFConfig(SPIx_SCK_GPIO_PORT, SPIx_SCK_SOURCE, SPIx_SCK_AF);

  GPIO_PinAFConfig(SPIx_MISO_GPIO_PORT, SPIx_MISO_SOURCE, SPIx_MISO_AF);    

  GPIO_PinAFConfig(SPIx_MOSI_GPIO_PORT, SPIx_MOSI_SOURCE, SPIx_MOSI_AF);

  GPIO_PinAFConfig(SPIx_NSS_GPIO_PORT, SPIx_NSS_SOURCE, SPIx_NSS_AF);

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_DOWN;

  /* SPI SCK pin configuration */

  GPIO_InitStructure.GPIO_Pin = SPIx_SCK_PIN;

  GPIO_Init(SPIx_SCK_GPIO_PORT, &GPIO_InitStructure);

  /* SPI  MISO pin configuration */

  GPIO_InitStructure.GPIO_Pin =  SPIx_MISO_PIN;

  GPIO_Init(SPIx_MISO_GPIO_PORT, &GPIO_InitStructure);  

  /* SPI  MOSI pin configuration */

  GPIO_InitStructure.GPIO_Pin =  SPIx_MOSI_PIN;

  GPIO_Init(SPIx_MOSI_GPIO_PORT, &GPIO_InitStructure);

   /* SPI  NSS pin configuration */

  GPIO_InitStructure.GPIO_Pin =  SPIx_NSS_PIN;

  GPIO_Init(SPIx_NSS_GPIO_PORT, &GPIO_InitStructure);

  /* SPI configuration -------------------------------------------------------*/

  SPI_I2S_DeInit(SPIx);

  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;

  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_Hard;

  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;

  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;

  SPI_InitStructure.SPI_CRCPolynomial = 0;

  /* Configure the Priority Group to 1 bit */                

  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);

  /* Configure the SPI interrupt priority */

  NVIC_InitStructure.NVIC_IRQChannel = SPIx_IRQn;

  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;

  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;

  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

  NVIC_Init(&NVIC_InitStructure);

}

/**

  * @brief  Program entry point

  * @param  None

  * @retval None

  */

int main(void)

{

 g_sRecvInfo.lpBuffer = g_cbRecvBuffer;

 g_sRecvInfo.uWritePos = 0;

 g_sRecvInfo.uReadPos = 0;

 g_sRecvInfo.uSize = RECV_SIZE;

  /* SPI configuration */

  SPI_Config();

   SPI_InitStructure.SPI_Mode = SPI_Mode_Slave;

  SPI_Init(SPIx, &SPI_InitStructure);

  /* Enable the Rx buffer not empty interrupt */

  SPI_I2S_ITConfig(SPIx, SPI_I2S_IT_RXNE, ENABLE);

  /* Enable the Tx empty interrupt */

  SPI_I2S_ITConfig(SPIx, SPI_I2S_IT_TXE, ENABLE);

  /* Enable the SPI peripheral */

  SPI_Cmd(SPIx, ENABLE);

  /* Main loop */

  while (1)

  {

  }

} 

#ifdef USE_FULL_ASSERT

/**

* @brief  assert_failed

*         Reports the name of the source file and the source line number

*         where the assert_param error has occurred.

* @param  File: pointer to the source file name

* @param  Line: assert_param error line source number

* @retval None

*/

void assert_failed(uint8_t* file, uint32_t line)

{

  /* User can add his own implementation to report the file name and line number,

  ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */

  /* Infinite loop */

  while (1)

  {}

}

#endif

/**

  * @}

  */ 

/**

  * @}

  */ 

/**

  * @}

  */ 

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

中断处理

/**

  * @brief  This function handles SPI interrupt request.

  * @param  None

  * @retval None

  */

void SPIx_IRQHANDLER(void)

{

  /* SPI in Receiver mode */

  if (SPI_I2S_GetITStatus(SPIx, SPI_I2S_IT_RXNE) == SET)

  {

      SPI_I2S_ReceiveData(SPIx);

  }

  /* SPI in Transmitter mode */

  if (SPI_I2S_GetITStatus(SPIx, SPI_I2S_IT_TXE) == SET)

  {

    if(g_sRecvInfo.uReadPos != g_sRecvInfo.uWritePos || g_sRecvInfo.bIsWriteNewCycle)

    {

        SPI_I2S_SendData(SPIx, *(g_sRecvInfo.lpBuffer + g_sRecvInfo.uReadPos));

        if(++g_sRecvInfo.uReadPos == g_sRecvInfo.uSize)

        {

          g_sRecvInfo.uReadPos = 0;

   g_sRecvInfo.bIsWriteNewCycle = 0;

        }

    }

    else

    {

        /* Send Transaction data */

        SPI_I2S_SendData(SPIx, 0xFF);

}

  }

}

结构定义及对应IO定义

#include

#include "stm32f4xx_spi.h"

typedef struct _Recv_cb

{

u8 *lpBuffer;

u32 uWritePos;

u32 uReadPos;

u32 uSize;

u8 bIsWriteNewCycle;

}RECV_STRUCT;

#define BUFFERSIZE                       100

#define SPIx                           SPI2

#define SPIx_CLK                       RCC_APB1Periph_SPI2

#define SPIx_CLK_INIT                  RCC_APB1PeriphClockCmd

#define SPIx_IRQn                      SPI2_IRQn

#define SPIx_IRQHANDLER                SPI2_IRQHandler

#define SPIx_NSS_PIN                  GPIO_Pin_12

#define SPIx_NSS_GPIO_PORT            GPIOB

#define SPIx_NSS_GPIO_CLK             RCC_AHB1Periph_GPIOB

#define SPIx_NSS_SOURCE               GPIO_PinSource12

#define SPIx_NSS_AF                   GPIO_AF_SPI2

#define SPIx_SCK_PIN                   GPIO_Pin_13

#define SPIx_SCK_GPIO_PORT             GPIOB

#define SPIx_SCK_GPIO_CLK              RCC_AHB1Periph_GPIOB

#define SPIx_SCK_SOURCE                GPIO_PinSource13

#define SPIx_SCK_AF                    GPIO_AF_SPI2

#define SPIx_MISO_PIN                  GPIO_Pin_14

#define SPIx_MISO_GPIO_PORT            GPIOB

#define SPIx_MISO_GPIO_CLK             RCC_AHB1Periph_GPIOB

#define SPIx_MISO_SOURCE               GPIO_PinSource14

#define SPIx_MISO_AF                   GPIO_AF_SPI2

#define SPIx_MOSI_PIN                  GPIO_Pin_15

#define SPIx_MOSI_GPIO_PORT            GPIOB

#define SPIx_MOSI_GPIO_CLK             RCC_AHB1Periph_GPIOB

#define SPIx_MOSI_SOURCE               GPIO_PinSource15

#define SPIx_MOSI_AF                   GPIO_AF_SPI2

注意:另外MASTER设备需要,先发送一个字节的时钟，然后再读取N个字节的时钟.