2019年03月08日 | STM32之SPI从机DMA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_FullDuplex;

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_Soft;

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SPI1 */

SPI_Cmd(SPI1, ENABLE);

/* 使能DMA接收 */

SPI_I2S_DMACmd(SPI1, SPI_I2S_DMAReq_Rx, ENABLE);

}

uint8_t rx_buf[100];

/* DMA配置 */

void DMA_config(void)

{

DMA_InitTypeDef DMA_InitStructure;

/* 使能DMA1时钟 */

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);

DMA_DeInit(DMA1_Channel2);  

DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)(&SPI1->DR);

DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)rx_buf;

DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;

DMA_InitStructure.DMA_BufferSize = 100;

DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;

DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;

DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;

DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;

DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;

DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;

DMA_Init(DMA1_Channel2, &DMA_InitStructure);

DMA_Cmd(DMA1_Channel2, 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);

/* 设置外部中断4的先占优先级为3,从占优先级为3 */

NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

}

/* 外部中断配置 */

void EXIT_config(void)

{

EXTI_InitTypeDef EXTI_InitStructure;

/* 将GPIOA_0和中断线连接 */

GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource4);

/* 设置中断线0位外部下降沿中断 */

EXTI_InitStructure.EXTI_Line = EXTI_Line4;

EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;

EXTI_InitStructure.EXTI_LineCmd = ENABLE;

EXTI_Init(&EXTI_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(); 

/* 外部中断配置 */

EXIT_config();

/* 中断嵌套控制器配置 */

NVIC_config();

/* DMA配置 */

DMA_config();

/* SPI配置 */

SPI_config();

while(1)

{

delay_ms(1000);

}

}

/* 外部中断4 */

void EXTI4_IRQHandler(void)

{

volatile uint8_t len;

/* 检查中断状态 */

if(EXTI_GetITStatus(EXTI_Line4) != RESET)  

{

len = 100 - DMA1_Channel2->CNDTR;

/* 接收完成，修改接收通道数据个数 */

DMA_Cmd(DMA1_Channel2, DISABLE);

DMA1_Channel2->CNDTR = 100;

DMA1_Channel2->CMAR = (uint32_t)rx_buf;

DMA_Cmd(DMA1_Channel2, ENABLE);

/* 清除中断状态寄存器 */

EXTI_ClearITPendingBit(EXTI_Line4);  

  }  

}