请教一个傻问题..

1万 · 2007-3-24 15:08

以下代码如何用GET_PORT()定义成一个宏?

        unsigned char t;
        t = PINA;
        s_port |= ((int)t&0x00ff);
        t = PINE;
        s_port |= (((int)t&0x0007) << 8);
        t = PINC;
        s_port |= ((int)(t&(BIT(7))) << 4);
        s_port |= ((int)(t&(BIT(6))) << 6);
        s_port |= ((int)(t&(BIT(5))) << 8);
        s_port |= ((int)(t&(BIT(4))) << 10);
        s_port |= ((int)(t&(BIT(3))) << 12);

1万 · 2007-3-24 15:45

#define  GET_PORT()        unsigned char t;
        t = PINA;
        s_port |= ((int)t&0x00ff);
        t = PINE;
        s_port |= (((int)t&0x0007) << 8);
        t = PINC;
        s_port |= ((int)(t&(BIT(7))) << 4);
        s_port |= ((int)(t&(BIT(6))) << 6);
        s_port |= ((int)(t&(BIT(5))) << 8);
        s_port |= ((int)(t&(BIT(4))) << 10);
        s_port |= ((int)(t&(BIT(3))) << 12);