STM32之SPI从机例程

#include "stm32f10x.h"

/* RCC时钟配置 */

void RCC_config(void)

{ 

ErrorStatus HSEStartUpStatus;

/* RCC寄存器设置为默认配置 */

RCC_DeInit();

/* 打开外部高速时钟 */

RCC_HSEConfig(RCC_HSE_ON);

/* 等待外部高速时钟稳定 */

HSEStartUpStatus = RCC_WaitForHSEStartUp();

if(HSEStartUpStatus == SUCCESS) 

{ 

/* 设置HCLK = SYSCLK */

RCC_HCLKConfig(RCC_SYSCLK_Div1);

/* 设置PCLK2 = HCLK */

RCC_PCLK2Config(RCC_HCLK_Div1);

/* 设置PCLK1 = HCLK / 2 */

RCC_PCLK1Config(RCC_HCLK_Div2);

// /* 设置FLASH代码延时 */

// FLASH_SetLatency(FLASH_Latency_2);

// /* 使能预取址缓存 */

// FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

/* 设置PLL时钟源为HSE倍频9 72MHz */

RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);

/* 使能PLL */

RCC_PLLCmd(ENABLE);

/* 等待PLL稳定 */

while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET);

/* 设置PLL为系统时钟源 */

RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

/* 等待系统时钟源切换到PLL */

while(RCC_GetSYSCLKSource() != 0x08);

}

}

/* GPIO配置 */

void GPIO_config(void)

{

GPIO_InitTypeDef GPIO_InitStructure;

/* 时钟配置 */

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

/* MISO配置为复用推挽输出 */

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

GPIO_Init(GPIOA, &GPIO_InitStructure);

/* SCK和MOSI配置为浮空输入 */

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_7;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;

GPIO_Init(GPIOA, &GPIO_InitStructure);

/* NSS配置为浮空输入 */

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;

GPIO_Init(GPIOA, &GPIO_InitStructure);

}

/* SPI配置 */

void SPI_config(void)

{

SPI_InitTypeDef SPI_InitStructure;

/* 时钟配置 */

RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO | RCC_APB2Periph_SPI1, ENABLE); 

/* 配置SPI模式 */

SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_RxOnly;

SPI_InitStructure.SPI_Mode = SPI_Mode_Slave;

SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;

SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;

SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;

SPI_InitStructure.SPI_NSS = SPI_NSS_Hard;

SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;

SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;

SPI_InitStructure.SPI_CRCPolynomial = 7;

SPI_Init(SPI1, &SPI_InitStructure);

/* 打开接收中断 */

SPI_I2S_ITConfig(SPI1, SPI_I2S_IT_RXNE, ENABLE); 

/* 打开SPI1 */

SPI_Cmd(SPI1, ENABLE);

}

/* 中断嵌套控制器配置 */

void NVIC_config(void)

{

NVIC_InitTypeDef NVIC_InitStructure;

/* 选择中断分组2 */

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);

/* 设置SPI1中断 */

NVIC_InitStructure.NVIC_IRQChannel = SPI1_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

}

/* 毫秒延时函数 */

void delay_ms(uint16_t time)

{    

uint16_t i = 0;  

while(time--)

{

i = 12000;

while(i--);    

}

}

/* 主函数 */

int main(void)

{ 

/* RCC时钟配置 */

RCC_config();

/* GPIO配置 */

GPIO_config(); 

/* 中断嵌套控制器配置 */

NVIC_config();

/* SPI配置 */

SPI_config();

while(1)

{

delay_ms(1000);

}

}

void SPI1_IRQHandler(void) 

{

volatile uint8_t i;

/* 接收中断 */

if(SPI_I2S_GetITStatus(SPI1, SPI_I2S_IT_RXNE) == SET)

{ 

/* 接收到数据 */

while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);

i = SPI_I2S_ReceiveData(SPI1);

while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);

SPI_I2S_SendData(SPI1, i);

/* 清除接收中断 */

SPI_I2S_ClearITPendingBit(SPI1, SPI_I2S_IT_RXNE);

} 

}