#define GPMCON (*(volatile unsigned long *)0x7F008820)  
#define GPMDAT (*(volatile unsigned long *)0x7F008824)  
  
void delay()  
{  
    volatile int i;  
    for(i = 0; i < 0x10000; i++);  
}  
  
int main()  
{  
    int i;  
    GPMCON = 0x1111;  
    GPMDAT = 0xC;  
    while(1)  
    {  
        for(i = 0; i < 4;i++)  
        {  
            GPMDAT = ~(1<<i);  
            delay();  
        }  
    }  
    return 0;  
}