函数RCC_APB1PeriphClockCmd() 和RCC_APB2PeriphClockCmd(),RCC_AHBPeriphClockCmd()
第一个参数形式如下RCC_APB2Periph_GPIOA 或者RCC_APB1Periph_TIM3
/** @defgroup APB2_peripheral
AFIO GPIOA GPIOB GPIOC ....GPIOG ADC1 ADC2 ADC3 SPI1 UART1 TIM1 TIM8 TIM9~11 TIM15~17
注意：AFIO当事件控制、重映射、外部中断需要使能AFIO时钟。
/** @defgroup APB1_peripheral
TIM2~7 TIM12~14 WWDG USB CAN1 CAN2 PWR DAC SPI2 SPI3 UART2~5 I2C1 I2C2
中断优先级分组
一般使用NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);设置一次。
以PE2为例，使用外部中断。
//初始化代码 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOE,ENABLE); GPIO_InitTypeDef GPIO_InitStructure; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;//KEY2 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //上拉输入 GPIO_Init(GPIOE, &GPIO_InitStructure);// RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); //使能复用时钟 GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource2); EXTI_InitTypeDef EXTI_InitStructure; NVIC_InitTypeDef NVIC_InitStructure; EXTI_InitStructure.EXTI_Line=EXTI_Line2; //KEY2 EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;//下降沿触发 EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;//使能外部中断2通道 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); //中断相应函数 void EXTI2_IRQHandler(void) { delay_ms(10);//消抖 if(KEY2==0) //按键PE2 { LED0=!LED0; } EXTI_ClearITPendingBit(EXTI_Line2); //清除line2上的中断标志位 }