3.顺序流水灯

八个发光二极管L1－L8分别接在单片机的P1.0－P1.7接口上，输出“0”时，发光二极管亮，开始时P1.0→P1.1→P1.2→P1.3→┅→P1.7→P1.6→┅→P1.0亮，重复循环。（向下向上循环）

汇编：

ORG 0
START: MOV R2,#8
MOV A,#0FEH
SETB C
LOOP: MOV P1,A
LCALL DELAY
RLC A
DJNZ R2,LOOP
MOV R2,#8
LOOP1: MOV P1,A
LCALL DELAY
RRC A
DJNZ R2,LOOP1
LJMP START
DELAY: MOV R5,#20 ;
D1: MOV R6,#20
D2: MOV R7,#248
DJNZ R7,$
DJNZ R6,D2
DJNZ R5,D1
RET
END

---

 C语言：
#include <AT89X51.H>
unsigned char i;
unsigned char temp;
unsigned char a,b;

void delay(void)
{
unsigned char m,n,s;
for(m=20;m>0;m--)
for(n=20;n>0;n--)
for(s=248;s>0;s--);
}
void main(void)
{
while(1)
{
temp=0xfe;
P1=temp;
delay();
for(i=1;i<8;i++)
{
a=temp<<i;
b=temp>>(8-i);
P1=a|b;
delay();
}
for(i=1;i<8;i++)
{
a=temp>>i;
b=temp<<(8-i);
P1=a|b;
delay();
}
}
} 

---

Lesson2_3流水灯

#include<reg52.h>

#include<intrins.h>

unsigned int a,b,c;

unsigned char d;

void delay(unsigned char);

void main()

{

       while(1)

      {

              d=0xfe;//1111 1110从下往下亮

           for(c=8;c>0;c--)

                     {

                            P1=d;

                            delay(100);

                            d=_crol_(d,1);//左移一位，循环左移L

                     }

              d=0x7f;//0111 1111从下往上亮

           for(c=8;c>0;c--)

                     {

                            P1=d;

                            delay(100);

                            d=_cror_(d,1); //右移一位，循环右移R

                     }

         }

}

void delay(unsigned char x5ms)

{

 for(b=x5ms;b>0;b--)

  for(a=300;a>0;a--);

}

 

---

流水灯且蜂鸣器发出声响

#include<reg52.h>

#include<intrins.h>

sbit beep=P2^3;

unsigned int a,b,c;

unsigned char d;

void delay(unsigned char);

void main() //主函数

{

       while(1)

      {

              d=0xfe;

           for(c=8;c>0;c--)

                     {

                            P1=d;

                            beep=0;

                            delay(100);

                            beep=1;//蜂鸣器下降沿发声

                            delay(100);

                            d=_crol_(d,1);

                     }

              d=0x7f;

           for(c=8;c>0;c--)

                     {

                            P1=d;

                            beep=0;

                            delay(100);

                            beep=1;

                            delay(100);

                            d=_cror_(d,1);

                     }

         }

}

void delay(unsigned char x5ms)

{

 for(b=x5ms;b>0;b--)

  for(a=300;a>0;a--);

}

---