使用定时器中断扫描按键,定时器中断每10ms进入一次,服务子函数执行大概需要21ms,进入中断后会不会打断服务子函数啊?
服务子函数里面是往24c02里面写数据的。当有按键按下时,进入服务子函数,数据是写不进去的。而我用JLink一步步调试发现进入服务子函数是能写进去数据的。
各位请指教一下......
[mw_shl_code=c,true]void TIM2_Int_Init(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
TIM_TimeBaseStructure.TIM_Period = 100;
TIM_TimeBaseStructure.TIM_Prescaler = 7199;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
TIM_ClearFlag(TIM2,TIM_FLAG_Update);
TIM_ITConfig(TIM2, TIM_IT_Update,ENABLE);
NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 4;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
TIM_Cmd(TIM2, ENABLE);
}
void TIM2_IRQHandler(void)
{
if(TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)
{
TIM_ClearITPendingBit(TIM2,TIM_IT_Update);
timer_cnt++;
if(1000 == timer_cnt)
{
timer_cnt = 0;
timeMultipleFlag=1;
}
Key_scan(); //按键扫描
}
}
int main()
{
//各种初始化
while(1)
{[/mw_shl_code]
[mw_shl_code=c,true] if(key1==0)[/mw_shl_code]
[mw_shl_code=c,true] {[/mw_shl_code]
[mw_shl_code=c,true] fun();//服务子函数;向24c02中写入数据。运行时间21ms左右。调试可以写入数据。正常运行写入不了。[/mw_shl_code]
[mw_shl_code=c,true] }
}
}[/mw_shl_code]
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