void DelayNS(uint32 dly)
{ uint32 i;
for(; dly>0; dly--)
for(i=0; i<3000; i++);
}
//持续蜂鸣
int persist(void)
{
uint32 m;
uint32 n;
uint32 k;
k=0;
n=30;
for(m=30;m>0;m--)
{
IO0SET = BEEPCON; // BEEPCON = 1
DelayNS(n);
IO0CLR = BEEPCON; // BEEPCON = 0
DelayNS(3);
n--;
if(n==0)
n++;
while( (IO0PIN&PIN_P014)==0 )
{ IO0SET = BEEPCON;
k=k+1;
}
while( (IO0PIN&PIN_P014)==1 )
if(k>0) IO0SET = BEEPCON;
else break;
if((IO0PIN&PIN_P014)==0)k=0;
}
return(0);
}
我单步执行看的，运行到最后一个while语句中，判定条件为真，且k＝0x00000009时，语句if(k>0) IO0SET = BEEPCON; 不会执行，直接跳出while了，应该是执行了else。是怎么回事阿，k是大于0的呀。 |
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