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我这边要测试一个周期为1us的脉冲次数,
芯片是STM32F103VCT6用PA6去测试,
输入33个只能检测到19个,而且每次都是19个,
请问是外部中断的速度问题呢还是什么原因呢?
void ex_pa6_Init()
{
GPIO_InitTypeDef GPIO_InitStructure;
EXTI_InitTypeDef EXTI_InitStruct;
NVIC_InitTypeDef NVIC_InitStruct;
// RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE); //使能SYSCFG时钟
/*初始化PA6*/
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;//浮空
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//将中断线0 与GPIOA映射起来,那么GPIOA.0与EXTI 1中断线连接了
GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource6);
// EXTI_DeInit();
/*初始化外部中断1为上升沿触发*/
EXTI_InitStruct.EXTI_Line = EXTI_Line6;
EXTI_InitStruct.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStruct.EXTI_Trigger = EXTI_Trigger_Rising;
EXTI_InitStruct.EXTI_LineCmd = ENABLE;//外部中断打开
EXTI_Init(&EXTI_InitStruct);
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_3);
NVIC_InitStruct.NVIC_IRQChannel = EXTI9_5_IRQn;
NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 2;
NVIC_InitStruct.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStruct);
}
void EXTI9_5_IRQHandler(void)
{
//确保是否产生了EXTI Line中断
if(EXTI_GetITStatus(EXTI_Line6) != RESET)
{
EXTI_ClearITPendingBit(EXTI_Line6); //清除中断标志位
freq_cnt++;
}
}
而且我将
freq_cnt++;
放在
EXTI_ClearITPendingBit(EXTI_Line6);
这句之前的话,只能检测到14个,看来提前清除中断标志位很有必要啊
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