Shahzad Aslam wrote:
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eric its the program i write in C is not working .... compiler is okey and i think the hardware is also okey


shahzad

try using a longer waiting period for the LED to lit up, in lorder to find out if the hardware is ok.
a waiting loop,instead of in interrupt, like this might help to detect the right functioning:
void wait()
{
char i,j,k;

for(i=0;i<3;i++)
for(j=0;i<255;j++)
for(k=0;k<255;k++);

}

main()
{
while (1){
litup();
wait()
litoff();
wait()
};
};

the wait func should be enough slow