单片机原理与C51程序设计基础教程 教学课件 作者 978 7 302 23075 5 第9章.docVIP

填空题 1.TXD RXD 2．SCON 3．固定 4. 300bit/s 5. 选择题 1．B 2．A 3．C 4．C 5.C 上机题 １. #includereg51.h #define uchar unsigned char #define uint unsigned int uint j,k; uchar i; char table[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f}; //定义流水灯 main() { TMOD = 0X20; //定时器初始化 TH1=0xcc; TL1=0xcc; //设定波特率 TR1=1; //无限循环执行一下发送和接收语句 SCON=0x50; //允许接收 P1=0xff; //所有led灭 while(1) { TI=0; //TI清零 for(i=0;i8;i++) //流水灯 { SBUF=table[i]; //发送数据 while(RI==0); //RI=0等待 RI=0; //RI清零 P1=SBUF; //接收数据并送P1口 while(TI==0); //TI=0等待 TI=0; //TI清零 for(j=0;j1000;j++) //延时 for(k=0;k100;k++); } if(i==8)i=0; //只有8个灯 } } 2. //发送 #include reg51.h #define uchar unsigned char void int4(void) ; char xdata *p; main() { P=0x3400; TMOD=0x20; TL1=0Xfd;TH1=0xfd; SCON=0x40; TR1=1;EA=1;ES=1; SBUF = *P; while(1); } void int4() interrupt 4 { TI=0; P++; SBUF=*P; if(P==0X34A0)EA=0; } //接收 #include reg51.h #define uchar unsigned char void int4(void) ; char xdata *p; main() { P=0x4400; TMOD=0x20; TL1=0Xfd;TH1=0xfd; SCON=0x50; TR1=1;EA=1;ES=1; SBUF = *P; while(1); } void int4() interrupt 4 { RI=0; *P=SBUF; P++; if(P==0X44A1)EA=0; } 3. #include reg51.h #define uchar unsigned char sbit P3_3=P3^3; uchar a=3; unsigned char tab[10]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90}; //共阳 void timer(uchar t); void int4(void) ; main() { uchar i,j; SCON=0;EA=0;ES=1; for(;;) { P3_3=1; for(i=0;i4;i++) { SBUF=tab[a]; j=a; while(j==a); } P3_3=0; timer(100); if(a=255)a=7; } void int4() interrupt4 { TI=0; a--; } void timer(uchar t) { uchar i; for(i=0;it;i++) { TMOD=0x01; TH0=-10000/256; TL0=-10000%256; TR0=1; while(!TF0); TF0=0; } }