指针数组变量指向IO口变量，方便循环操作

    #define PAOUT(n)                 *((volatile unsigned long *)(0x42000000+0x20014*32+n*4))
    #define PBOUT(n)                 *((volatile unsigned long *)(0x42000000+0x20414*32+n*4))
    #define PCOUT(n)                 *((volatile unsigned long *)(0x42000000+0x20814*32+n*4))
    #define PDOUT(n)                 *((volatile unsigned long *)(0x42000000+0x20c14*32+n*4))
    #define PEOUT(n)                 *((volatile unsigned long *)(0x42000000+0x21014*32+n*4))
    #define PFOUT(n)                 *((volatile unsigned long *)(0x42000000+0x21414*32+n*4))
    #define PGOUT(n)                 *((volatile unsigned long *)(0x42000000+0x21814*32+n*4))
    #define PHOUT(n)                 *((volatile unsigned long *)(0x42000000+0x21C14*32+n*4))

    #define PAIN(n)                 *((volatile unsigned long *)(0x42000000+0x20010*32+n*4))
    #define PBIN(n)                 *((volatile unsigned long *)(0x42000000+0x20410*32+n*4))
    #define PCIN(n)                 *((volatile unsigned long *)(0x42000000+0x20810*32+n*4))
    #define PDIN(n)                 *((volatile unsigned long *)(0x42000000+0x20c10*32+n*4))
    #define PEIN(n)                 *((volatile unsigned long *)(0x42000000+0x21010*32+n*4))/            #define PFIN(n)                 *((volatile unsigned long *)(0x42000000+0x21410*32+n*4))
    #define PGIN(n)                 *((volatile unsigned long *)(0x42000000+0x21810*32+n*4))
    #define PHIN(n)                 *((volatile unsigned long *)(0x42000000+0x21C10*32+n*4))

volatile unsigned long *pIo[2];

pIo[0] = &PEIN(3);

pIo[1] = &PEIN(3);

for(i = 0;i < 2;i++)

{

    if(*pIo[0])

    {

    ...

    }

}