给我写一个关于c51单片机简易东西南北交通灯的c语言程序

下面是一个简单的C51单片机东南西北交通灯程序：

#include <reg52.h>

sbit NorthRed = P1^0;
sbit NorthYellow = P1^1;
sbit NorthGreen = P1^2;
sbit SouthRed = P1^3;
sbit SouthYellow = P1^4;
sbit SouthGreen = P1^5;
sbit EastRed = P1^6;
sbit EastYellow = P1^7;
sbit EastGreen = P3^0;
sbit WestRed = P3^1;
sbit WestYellow = P3^2;
sbit WestGreen = P3^3;

void delay(unsigned int);
void TrafficLight();

void main()
{
    while(1)
    {
        TrafficLight();
    }
}

void TrafficLight()
{
    NorthGreen = 1;
    NorthYellow = 0;
    NorthRed = 0;
    SouthGreen = 1;
    SouthYellow = 0;
    SouthRed = 0;

    delay(5000);

    NorthGreen = 0;
    NorthYellow = 1;
    NorthRed = 0;
    SouthGreen = 0;
    SouthYellow = 1;
    SouthRed = 0;

    delay(2000);

    NorthGreen = 0;
    NorthYellow = 0;
    NorthRed = 1;
    SouthGreen = 0;
    SouthYellow = 0;
    SouthRed = 1;
    EastGreen = 1;
    EastYellow = 0;
    EastRed = 0;
    WestGreen = 1;
    WestYellow = 0;
    WestRed = 0;

    delay(5000);

    EastGreen = 0;
    EastYellow = 1;
    EastRed = 0;
    WestGreen = 0;
    WestYellow = 1;
    WestRed = 0;

    delay(2000);

    EastGreen = 0;
    EastYellow = 0;
    EastRed = 1;
    WestGreen = 0;
    WestYellow = 0;
    WestRed = 1;
}

void delay(unsigned int time)
{
    unsigned int i, j;
    for(i=0;i<time;i++)
        for(j=0;j<125;j++);
}

该程序使用了定时器延时函数 `delay()`，以及控制红绿灯亮灭的代码。程序中分为两个状态，一个是南北方向绿灯亮，东西方向红灯亮，另一个状态则是南北方向黄灯亮，东西方向红灯亮。通过不断的循环，实现交通灯的变化。