【单片机开发思想进阶02：单个定时器实现多路并行非阻塞定时功能】

/*基于一个定时器加软件并行实现多个LED闪烁*/ #include "reg52.h" /*宏定义：D1~D3的闪烁时间*/ #define D1_DELAY_XMS 1000 #define D2_DELAY_XMS 500 #define D3_DELAY_XMS 100 /*********************************/ #define u16 unsigned int sbit D1 = P2^0; sbit D2 = P2^1; sbit D3 = P2^2; /*位定义：D1~D3延时时间到的标志位*/ bit D1_Delay_ON; bit D2_Delay_ON; bit D3_Delay_ON; /*********************************/ u16 D1DelayCount, D2DelayCount, D3DelayCount; //1ms计数值定义 void Timer0Init(void); void main(void) { Timer0Init(); D1DelayCount = D1_DELAY_XMS; D2DelayCount = D2_DELAY_XMS; D3DelayCount = D3_DELAY_XMS; //延时计数的装载初始 while(1) { if(D1_Delay_ON) //定时延时到 { D1 = ~D1; D1_Delay_ON = 0; //定时到标志位清零，为下一次延时做准备 D1DelayCount = D1_DELAY_XMS; //重载用于延时的计数值，为下次延时准备 } if(D2_Delay_ON) { D2 = ~D2; D2_Delay_ON = 0; D2DelayCount = D2_DELAY_XMS; } if(D3_Delay_ON) { D3 = ~D3; D3_Delay_ON = 0; D3DelayCount = D3_DELAY_XMS; } } } void Timer0Init(void) //1毫秒@12MHz { TMOD &= 0xF0; //设置定时器模式 TMOD |= 0x01; //定时模式1 TL0 = 0x18; //设置定时初始值 TH0 = 0xFC; //设置定时初始值 TF0 = 0; //清除TF0标志 TR0 = 1; //定时器0开始计时 ET0 = 1; //开启定时器中断 EA = 1; //开启总中断 } void time0_isr(void) interrupt 1 //定时中断函数 { TR0 = 0; //先清零，确保执行完中断函数再开启定时 TL0 = 0x18; //设置定时初始值 TH0 = 0xFC; //设置定时初始值 if(D1DelayCount) //D1延时的软件定时器 { D1DelayCount --; if(!D1DelayCount) D1_Delay_ON = 1; //D1的延时时间到 } if(D2DelayCount) { D2DelayCount --; if(!D2DelayCount) D2_Delay_ON = 1; } if(D3DelayCount) { D3DelayCount --; if(!D3DelayCount) D3_Delay_ON = 1; } TR0 = 1; }