不知道是否是没配置好，使用STM32L151，IO从示波器是可以以33ns的速度翻转，也就是MCU以及IO的总线速度是32MHZ
按道理应该33nS*12=396nS再加上各种RP值，怎么也应该也小于1uS吧，但使用实际示波器观测，发现在外部上升沿后3uS以上的时间才进中断！
中断的周期是10uS，除了这个外部中断没有用到其他中断。
初始化设置如下
- //BUSY_IO中断配置
- void BUSY_I0_Config(void)
- {
- GPIO_InitTypeDef GPIO_InitStructure1;
- NVIC_InitTypeDef NVIC_InitStructure1;
- EXTI_InitTypeDef EXTI_InitStructure1;
- /* Configure PA0 pin as input floating */
- GPIO_InitStructure1.GPIO_Mode = GPIO_Mode_IN;
- GPIO_InitStructure1.GPIO_PuPd = GPIO_PuPd_UP;
- GPIO_InitStructure1.GPIO_Speed = GPIO_Speed_40MHz;
- GPIO_InitStructure1.GPIO_Pin = GPIO_Pin_2;
- GPIO_Init(GPIOA, &GPIO_InitStructure1);
- /* Enable SYSCFG clock */
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
- /* Connect EXTI0 Line to PA0 pin */
- SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource1);
- /* Configure EXTI0 line */
- EXTI_InitStructure1.EXTI_Line = EXTI_Line2;
- EXTI_InitStructure1.EXTI_Mode = EXTI_Mode_Interrupt;
- EXTI_InitStructure1.EXTI_Trigger = EXTI_Trigger_Rising;
- EXTI_InitStructure1.EXTI_LineCmd = ENABLE;
- EXTI_Init(&EXTI_InitStructure1);
- /* Enable and set EXTI0 Interrupt to the lowest priority */
- NVIC_InitStructure1.NVIC_IRQChannel = EXTI2_IRQn;
- NVIC_InitStructure1.NVIC_IRQChannelPreemptionPriority = 0;
- NVIC_InitStructure1.NVIC_IRQChannelSubPriority = 0;
- NVIC_InitStructure1.NVIC_IRQChannelCmd = ENABLE;
- NVIC_Init(&NVIC_InitStructure1);
- }
- void EXTI2_IRQHandler(void)
- {
- GPIOA->BSRRH = GPIOA->BSRRL = (1<<8);
- if(EXTI->PR & EXTI_Line2)
- {
- EXTI->PR = EXTI_Line2;//清中断
- }
- }
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