原子操作

只看该作者 · 2018-10-8 21:37

用TIME0循环读四路风扇转速，是直接用time0来计算脉宽，我是循环开中断来做的，
（TA0CCTL1&= ~CCIE;  TA0CCTL2|= CCIE;）-->（TA0CCTL2&= ~CCIE;  TA0CCTL3|= CCIE;）......
（TA0CCTL4&= ~CCIE;  TA0CCTL1|= CCIE;）
在中断里面关掉自己中断的使能和 TA0CTL|=TACLR;有没有潜在的危险？

char  fan_times_tmp = 0;                //用来记录次数的中间变量
char  fan_flag = 0;                      //进入中断标志位

#pragma vector=TIMER0_A1_VECTOR
//__interrupt void TIMER0_A1_ISR(void)

__interrupt void TIMER0_A(void)
{

  switch(TA0IV)
  {

case  0: break;                            // No interrupt
case  2:
         if((TA0CCTL1&CM_2)&&(fan_flag == 0))
         {                                  //清计数器
            TA0CTL|=TACLR;

            fan_flag = 1;
            P3OUT ^= BIT2;

         }
         else if((TA0CCTL1&CM_2)&&(fan_flag == 1))
         {



         speed_tmp[fan_times_tmp++] = TA0CCR1;
            fan_flag = 0;
            if(fan_times_tmp == fan_data_time)
            {
               fan_a = 0;
               for(fan_i=0;fan_i<fan_data_time;fan_i++)
               fan_a +=speed_tmp[fan_i];
               fan_a >>= 5;             //除以4求平均值,以免数据不停跳变
               fan_speed[0] = fan_a;
               fan_i = 0;


            // TA0CCTL1&= ~CCIE;
            // TA0CCTL2|= CCIE;
               fan_times_tmp = 0;
            }

         }


   TA0CCTL1 &= ~CCIFG; break;

            break;                         // CCR1 not used
case  4:
   if((TA0CCTL2&CM_2)&&(fan_flag == 0))
         {                                  //清计数器
            TA0CTL|=TACLR;
            fan_flag = 1;
         }
         else if((TA0CCTL2&CM_2)&&(fan_flag == 1))
         {


            speed_tmp[fan_times_tmp++] = TA0CCR2;


            fan_flag = 0;
            if(fan_times_tmp == fan_data_time)
            {
               fan_a = 0;
               for(fan_i=0;fan_i<fan_data_time;fan_i++)
               fan_a +=speed_tmp[fan_i];
               fan_a >>= 5;             //除以4求平均值,以免数据不停跳变
               fan_speed[0] = fan_a;
               fan_i = 0;

               TA0CCTL2&= ~CCIE;
               TA0CCTL3|= CCIE;
               fan_times_tmp = 0;
            }

         }

   TA0CCTL2 &= ~CCIFG;
   break;

   break;          // CCR2 not used
case  6:
   if((TA0CCTL3&CM_2)&&(fan_flag == 0))
         {                                  //清计数器
            TA0CTL|=TACLR;
            fan_flag = 1;
         }
         else if((TA0CCTL3&CM_2)&&(fan_flag == 1))
         {


            speed_tmp[fan_times_tmp++] = TA0CCR3;



            fan_flag = 0;
            if(fan_times_tmp == fan_data_time)
            {
               fan_a = 0;
               for(fan_i=0;fan_i<fan_data_time;fan_i++)
               fan_a +=speed_tmp[fan_i];
               fan_a >>= 5;             //除以4求平均值,以免数据不停跳变
               fan_speed[0] = fan_a;
               fan_i = 0;

               TA0CCTL3&= ~CCIE;
               TA0CCTL1|= CCIE;
               fan_times_tmp = 0;
            }
         }

   TA0CCTL3 &= ~CCIFG;
   break;       // reserved
case  8:
   if((TA0CCTL4&CM_2)&&(fan_flag == 0))
         {                                  //清计数器
            TA0CTL|=TACLR;
            fan_flag = 1;
         }
         else if((TA0CCTL4&CM_2)&&(fan_flag == 1))
         {


            speed_tmp[fan_times_tmp++] = TA0CCR4;


            fan_flag = 0;
            if(fan_times_tmp == fan_data_time)
            {
               fan_a = 0;
               for(fan_i=0;fan_i<fan_data_time;fan_i++)
               fan_a +=speed_tmp[fan_i];
               fan_a >>= 5;             //除以4求平均值,以免数据不停跳变
               fan_speed[0] = fan_a;
               fan_i = 0;

               TA0CCTL4&= ~CCIE;
               TA0CCTL1|= CCIE;
               fan_times_tmp = 0;
            }

         }

   TA0CCTL4 &= ~CCIFG;
   break;       // reserved
case 10:                         // reserved
case 12:                      // reserved
case 14: //TA1CCTL1 &= ~COV;                // overflow

   break;

default:break;

  }
}