按键中断总结

一、RCC初始化

			/****************************************************************************
			* Function Name : RCC_Configuration
			* Description : Sets System clock frequency to 72MHz and configure HCLK, PCLK2
			* and PCLK1 prescalers.
			* Input : None
			* Output : None
			* Return : None
			****************************************************************************/
			void RCC_Configuration(void)
			{
			    /* Deinitialize the RCC registers */
			    RCC_DeInit();

			    /* Enable the HSE */
			    RCC_HSEConfig(RCC_HSE_ON);

			    /* Wait till HSE is ready and if Time out is reached exit */
			    HSEStartUpStatus = RCC_WaitForHSEStartUp();
			    if(HSEStartUpStatus == SUCCESS)
			    {
			        /* Add here PLL ans system clock config */

			        /* Enable The Prefetch Buffer */
			        FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

			        /* Configure Tthe Latency cycle: Set 0 Latency cycles */
			        FLASH_SetLatency(FLASH_Latency_2);

			        /* Configure HCLK such as HCLK = SYSCLK */
			        RCC_HCLKConfig(RCC_SYSCLK_Div1);

			        /* PCLK2 = HCLK */
			        RCC_PCLK2Config(RCC_HCLK_Div1);

			        /* PCLK1 = HCLK/2 */
			        RCC_PCLK1Config(RCC_HCLK_Div2);

			        /* Select HSE as system clock source*/
			        RCC_SYSCLKConfig(RCC_SYSCLKSource_HSE);

			        /* PLLCLK = 8MHz * 9 = 72MHz */
			        RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);

			        /* ADCCLK = PCLK/4 */
			        RCC_ADCCLKConfig(RCC_PCLK2_Div4);

			        /* Enable PLL */
			        RCC_PLLCmd(ENABLE);

			        /* Wait till PLL is ready */
			        while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET);

			        /* Select PLL as system clock source */
			        RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK); /* Wait till HSE is used as system clock source */
			        while(RCC_GetSYSCLKSource() != 0x08)
			        {

			        }
			    }
			    else
			    {
			        /* If HSE fails to start-up. */
			        while(1)
			        {
			        }
			    }
			}

相比之前的时钟初始化，多初始化了ADCCLK。

二、GPIO初始化

			/****************************************************************************
			* Function Name : GPIO_Configuration
			* Description :
			* Input : None
			* Output : None
			* Return : None
			****************************************************************************/
			void GPIO_Configuration(void)
			{
			    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);

			    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
			    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
			    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
			    GPIO_Init(GPIOB, &GPIO_InitStructure);

			    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
			    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
			    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
			    GPIO_Init(GPIOB, &GPIO_InitStructure);
			}

使用PB8作为推挽输出，PB6为浮空输入。

三、NVIC初始化

			/****************************************************************************
			* Function Name : NVIC_Configuration
			* Description : Configures Vector Table base location.
			* Input : None
			* Output : None
			* Return : None
			****************************************************************************/
			void NVIC_Configuration(void)
			{
			    NVIC_InitTypeDef NVIC_InitStructure;

			#ifdef VET_TAB_RAM
			    /* Set the Vector Table base location at 0x2000 0000 */
			    NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);
			#else
			    /* Set the Vector Table base location at 0x8000 0000 */
			    NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);
			#endif

			    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

			    NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn;
			    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
			    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
			    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
			    NVIC_Init(&NVIC_InitStructure);
			}

因位PB6位输入，也就是外部中断源。所以初始化EXTI9_5_IRQn作为外部中断源

四、EXTI初始化

			/****************************************************************************
			* Function Name : EXTI_PE6_Config
			* Description :
			* Input : None
			* Output : None
			* Return : None
			****************************************************************************/
			void EXTI_PE6_Config(void)
			{
			    GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource6);

			    EXTI_InitStructure.EXTI_Line = EXTI_Line6;
			    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
			    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
			    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
			    EXTI_Init(&EXTI_InitStructure);

			    EXTI_GenerateSWInterrupt(EXTI_Line6);

			}

设置了外部中断源，把GPIOB6作为中断源。外部中断线是6，结合原理图使用下降沿触发。
EXTI_GenerateSWInterrupt是触发一次软件中断。

同时需要编写中断函数在stm32f10x_it.c中：

			/*******************************************************************************
			* Function Name : EXTI9_5_IRQHandler
			* Description : This function handles External lines 9 to 5 interrupt request.
			* Input : None
			* Output : None
			* Return : None
			*******************************************************************************/
			void EXTI9_5_IRQHandler(void)
			{
			    if(EXTI_GetITStatus(EXTI_Line6) != RESET)
			    {
			        GPIO_WriteBit(GPIOB, GPIO_Pin_8, (BitAction)(1-GPIO_ReadOutputDataBit(GPIOB, GPIO_Pin_8)));

			        EXTI_ClearITPendingBit(EXTI_Line6);
			    }
			}

五、main函数

			/****************************************************************************
			* Function Name : main
			* Description : Main program.
			* Input : None
			* Output : None
			* Return : None
			****************************************************************************/
			int main(void)
			{
			    RCC_Configuration();

			    NVIC_Configuration();

			    GPIO_Configuration();

			    EXTI_PE6_Config();

			    while(1)
			    {
			    }
			}