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
*
* <h2><center>© COPYRIGHT 2012 STMicroelectronics</center></h2>
*
* 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 <string.h>
#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.