/*定时1ms,1个周期30ms,脉冲频率为33HZ */
/* */
#include typedef unsigned char uchar; sbit P0_0=P0^0; sbit P0_1=P0^1; sbit P0_2=P0^2; sbit P0_3=P0^3; sbit P0_4=P0^4; sbit P2_0=P2^0; sbit P2_1=P2^1; sbit P2_2=P2^2; sbit P2_3=P2^3; sbit P2_4=P2^4; sbit P3_4=P3^4; uchar time=0; uchar period=30; uchar high=10; uchar th0=0; uchar tl0=1; bit dir; void dealy() { uchar i; for(i=0;i<100;i++); } void timer0() interrupt 1 using 1 { TH0=0xfc; /*定时器初值重装载*/ TL0=0x18; time++; P3_4=~P3_4; if(dir==1) { if(time==high) /*高电平持续时间结束，变低*/ P2_0=th0; /*经过反相器反相*/ else if(time==period) /*周期时间到，变高*/ { time=0; P2_0=tl0; /*经过反相器反相*/ } } else if(time==high) /*高电平持续时间结束，变低*/ P2_1=th0; /*经过反相器反相*/ else if(time==period) /*周期时间到，变高*/ { time=0; P2_1=tl0; /*经过反相器反相*/ } } void main() { P0=0x00; P2=0x00; TMOD=0x01; /*定时器0方式1*/ TH0=0xfc; /*定时器装载初值，设置脉冲信号的占空比为1／5*/ TL0=0x18; ET0=1; /*开定时器0中断*/ TR0=1; /*启动定时器0*/ while(1) { if(P0_0==1) EA=1; /*开CPU中断*/ if(P0_1==1) EA=0; /*关CPU中断*/ if(P0_2==1) { dir=~dir; /*转向控制*/ while(P0_2!=0) {}; } if(P0_3==1) { high++; if(high==30) high=0; while(P0_3!=0) {}; } } }
