单片机IO位域如何操作？

1、位域操作单片机IO口，结构清晰，且减少代码运算量（虽然不多哈）。


2、如果8个IO口不是P0/P1/P2/P3等，而是不同的GPIO口组合的8个，那建议使用位域操作。


范例：优先考虑，赋值一次后分别对8个IO单独赋值。


#define LED_ROW1    P2_1
#define LED_ROW1    P2_0
#define LED_ROW3    P0_1
#define LED_ROW4    P0_5
#define LED_ROW5    P2_5
#define LED_ROW6    P3_1
#define LED_ROW7    P3_2
#define LED_ROW8    P1_1
typedef union
{
        unsigned char byte;
        struct
        {
                unsigned char bit_8:1;//高8位
                unsigned char bit_7:1;
                unsigned char bit_6:1;
                unsigned char bit_5:1;
                unsigned char bit_4:1;
                unsigned char bit_3:1;
                unsigned char bit_2:1;
                unsigned char bit_1:1;//低0位
        }bits;
}LED_union_typedef;

LED_union_typedef LED_ROW={0XFF};

void LED_SW(unsigned char value)
{
    LED_ROW.byte=value;//赋值

    LED_ROW1=LED_ROW.bits.bit_8;
    LED_ROW2=LED_ROW.bits.bit_7;
    LED_ROW3=LED_ROW.bits.bit_6;
    LED_ROW4=LED_ROW.bits.bit_5;
    LED_ROW5=LED_ROW.bits.bit_4;
    LED_ROW6=LED_ROW.bits.bit_3;
    LED_ROW7=LED_ROW.bits.bit_2;
    LED_ROW8=LED_ROW.bits.bit_1;
}



范例：不建议，每次运行一下把结果赋给IO


#define LED_ROW1    P2_1
#define LED_ROW1    P2_0
#define LED_ROW3    P0_1
#define LED_ROW4    P0_5
#define LED_ROW5    P2_5
#define LED_ROW6    P3_1
#define LED_ROW7    P3_2
#define LED_ROW8    P1_1


void LED_SW(unsigned char value)
{
    LED_ROW1=value&0x01;
    LED_ROW2=value&0x02;
    LED_ROW3=value&0x04;
    LED_ROW4=value&0x08;
    LED_ROW5=value&0x10;
    LED_ROW6=value&0x20;
    LED_ROW7=value&0x40;
    LED_ROW8=value&0x80;
}