代码1:
void dely()
{
int i=1000000;
while(i--);
}
void show()
{
int i=0;
unsigned *led_con=( unsigned *)0x7f008800;
unsigned *led_dat=( unsigned *)0x7f008808;
unsigned data=0xffef;
*led_con=0x11110000;
*led_dat=0xffef;
while(1)
{
i++;
dely();
*led_dat=data<
if(i>4)
{
data=0xffef;
i=0;
}
}
}
代码2:
void dely()
{
int i=1000000;
while(i--);
}
void show()
{
int i=0;
unsigned *led_con=( unsigned *)0x7f008800;
unsigned *led_dat=( unsigned *)0x7f008808;
unsigned data=0xffef;
*led_con=0x11110000;
*led_dat=0xffef;
while(1)
{
i++;
dely();
*led_dat=*led_dat<
if(i>4)
{
*led_dat=0xffef;
i=0;
}
}
}
两段代码中*led_dat中的值应该是一样的,但是在开发板中运行的效果确实不相同,这个该怎么解释?