- #include<reg52.h>
- sfr P3M1 = 0xb1; //PxM1.n,PxM0.n =00--->双向口模, 01---> 推挽输出模式
- sfr P3M0 = 0xb2; // =10--->高阻输入模式, 11---> 开漏模式
- sbit LED1=P3^2;
- sbit LED2=P3^3;
- sbit LED3=P3^4;
- sbit LED4=P3^5;
- void delay(unsigned int t);
- void main()
- {
- P3M1 = 0x00; //设置P3.2~P3.7为推挽输出模式
- P3M0 = 0xFC;
-
- while(1)
- {
- LED1=0;
- LED2=0;
- LED3=0;
- LED4=0;
- delay(20);
- LED1=1;
- LED2=1;
- LED3=1;
- LED4=1;
- delay(20);
-
- }
-
- }
- void delay(unsigned int t)
- {
- int i, j;
- do
- {
- for (i=0; i<1000; i++)
- for (j=0; j<500; j++);
- } while (--t);
- }
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