delay(500); P1=0x55; delay(500); } }
4：如下图，编程实现LED循环显示字符：“H” →“L” →“E”。 #include
char led_ mod[]={0x76,0x38,0x79}; //LED显示字模 void delay( unsigned int time) { unsigned int j = 0; for(; time>0;time--) for( j=0;j<200;j++); }
void main(void) { char i=0; while(1)
{for(i=0;i<=2;i++) { P0=led_mod[i]; delay(500); } }}
5、开机时LED全熄，然后根据按键动作使相应灯亮，并将亮灯保持到按压其它键时为止。 #include
R5R6R7R8void main() {
U1 char key = 0; P2=0; while(1){
key = ~P0 & 0x0f; //读取按键状态 D1 if (key != 0) P2 = key; //显示到led D2 }
D3}
D4
6、在P0口连接一个共阴极数码管，使之循环显示0～9数字。 #include
while(1){ for(i=0;i<=9;i++) { P0=led_mod[i]; delay(500); } } }
7、设计一个开关控制报警器：用K1开关控制报警器，程序控制P1.0输出两种不同频率的声音，模拟很逼真的报警效果.
C2C1#include
22uF1930pF#define uchar unsigned char XTAL1X1CRYSTALC318sbit SPK=P1^0; XTAL2R11k30pFsbit K1=P1^7; 9RSTvoid Alarm(uchar t) //发声函数
29{ uchar i,j; PSEN30ALE31EA for(i=0;i<200;i++) //循环次数控制音频的持续时间 LS11 { SPK=~SPK; P1.02P1.13P1.24 for(j=0;j void main() { SPK=0; while(1) { if(K1==1) { Alarm(90); Alarm(150); } } } 8、设单片机的fosc=12MHz，采用T0定时方式1在P1.0脚上输出周期为2ms的方波。 分析：1ms定时的计数初值应为： a = 216 – t* fos / 12 = 216 – 1000* 12/ 12 = 64536 = 0xfc18 TH0 = 0xfc TL0 = 0x18 ① 查询法： U?#include 18XTAL2void main (void) { TMOD = 0x01; //T0定时方式1 9RST TR0=1; //启动T0 for( ; ; ) 29PSEN30ALE{ TH0 = 0xfc; //装载计数初值 31EA TL0 = 0x18; while(!TF0); //查询等待TF0复位 1AP1.02P1.13 P1_0 =!P1_0; //定时时间到P1.0反相 BP1.24P1.35CP1.4 TF0 = 0; //软件清TF0 6P1.57DP1.6 }} 8P1.780C51P0.0/AD0P0.1/AD1P0.2/AD2P0.3/AD3P0.4/AD4P0.5/AD5P0.6/AD6P0.7/AD7P2.0/A8P2.1/A9P2.2/A10P2.3/A11P2.4/A12P2.5/A13P2.6/A14P2.7/A15P3.0/RXDP3.1/TXDP3.2/INT0P3.3/INT1P3.4/T0P3.5/T1P3.6/WRP3.7/RD393837363534333221222324252627281011121314151617U180C51P0.0/AD0P0.1/AD1P0.2/AD2P0.3/AD3P0.4/AD4P0.5/AD5P0.6/AD6P0.7/AD7P2.0/A8P2.1/A9P2.2/A10P2.3/A11P2.4/A12P2.5/A13P2.6/A14P2.7/A15P3.0/RXDP3.1/TXDP3.2/INT0P3.3/INT1P3.4/T0P3.5/T1P3.6/WRP3.7/RD393837363534333221222324252627281011121314151617②中断法： #include timer0 () interrupt 1 //T0中断函数 { P1_0 = !P1_0; //P1.0取反 TH0 = 0xfc; //装载计数初值 TL0 = 0x18; } main () { TMOD = 0x01; //T0定时方式1 TH0 = 0xfc; //装载计数初值 TL0 = 0x18; EA=1; //开总中断 ET0=1; //开T0中断 TR0=1; //启动T0 while(1); } 9、使用T1，分别用工作方式1、方式2 、方式0实现1s延时函数，晶振频率为12M. C130pFX1CRYSTALC310uFR110k 10、程序运行开始时先显示“00”，随后显示数值逐渐增大。待计数到59后，自动从“00”开始。 //定时中断方式实现的电子秒表 #include unsigned char t=0; //定义中断次数计数器 unsigned char second=0; //定义秒计数器 unsigned char code table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f}; timer0() interrupt 1{ //定时器0中断函数 TR0=0; TH0 =0x3c; //初值重装载 TL0 =0xb0; t++; //中断次数增1 if(t==20){ //若中断20次，相当于1秒 t=0; //中断次数计数器清零 second++; //秒计数器清零 } if(second==60) second=0; //若秒计数器=60，清零 P0=table[second/10]; //P0口输出显示 P2=table[second]; //P2口输出显示 TR0=1; } main(){ TMOD=0x01; //定义T0定时方式1 TH0 =0x3c; //50ms溢出初值 TL0 =0xb0; P0=table[second/10]; //P0口输出显示 P2=table[second]; //P2口输出显示 TR0=1; //启动定时器 ET0=1; //打开定时器0中断 EA=1; //打开总中断 while(1){} //主程序循环 } C1C2C2 30pF30pFX1U1R2-R7/1k U11939XTAL1P0.0/AD038P0.1/AD137P0.2/AD2CRYSTAL 1836XTAL2P0.3/AD335P0.4/AD434P0.5/AD5C3 33P0.6/AD6932RSTP0.7/AD7 2110uFR1P2.0/A830pF19XTAL118XTAL29RSTP0.0/AD0P0.1/AD1P0.2/AD2P0.3/AD3P0.4/AD4P0.5/AD5P0.6/AD6P0.7/AD7393837363534333221222324252627281011121314151617P0.0P0.1P0.2P0.3P0.4P0.5P0.6P0.0P0.1P0.2P0.3P0.4P0.5P0.6PULLUP293031PSENALEEAP2.0/A8P2.1/A9P2.2/A10P2.3/A11P2.4/A12P2.5/A13P2.6/A14P2.7/A15P2.0P2.1P2.2P2.3P2.4P2.5P2.6P0.0P0.1P0.2P0.3P0.4P0.5P0.6P2.0P2.1P2.2P2.3P2.4P2.5P2.6R2220D1LED-YELLOW10k293031PSENALEEAP2.1/A9P2.2/A10P2.3/A11P2.4/A12P2.5/A13P2.6/A14P2.7/A15P3.0/RXDP3.1/TXDP3.2/INT0P3.3/INT1P3.4/T0P3.5/T1P3.6/WRP3.7/RD22232425262728101112131415161712345678P1.0P1.1P1.2P1.3P1.4P1.5P1.6P1.7P3.0/RXDP3.1/TXDP3.2/INT0P3.3/INT1P3.4/T0P3.5/T1P3.6/WRP3.7/RDLED1LED212345678P1.0P1.1P1.2P1.3P1.4P1.5P1.6P1.7 第10题图 第11题图 11、定时器控制单只LED（说明：LED在定时器的控制下不断闪烁，闪烁间隔时间为1S ）。 ①查询方法： ②中断方法： #include }} 12、 利用T0的计数功能，对按下按键的次数计数，显示在数码管上。一通电，数码管显示“00” 。 #include unsigned char code table[]={0x3f,0x06,0x5b,0x4f, 0x66,0x6d,0x7d,0x07,0x7f,0x6f}; unsigned char count=0; //计数器赋初值 RP1sbit p1_0=P1^0; RESPACK-7 VCCint0_srv () interrupt 1{ //T0中断函数 U1 if(++count==100) count=0; //判断循环是否超限 LED1a1939XTAL1P0.0/AD0b38 P0=table[count/10]; //显示十位数 P0.1/AD1c37P0.2/AD2d1836XTAL2P0.3/AD3e35 P2=table[count]; //显示个位数 P0.4/AD4f34P0.5/AD5g33P0.6/AD6932} RSTP0.7/AD7a21P2.0/A8b22 P2.1/A9c23P2.2/A10d2924PSENP2.3/A11e3025main(){ ALEP2.4/A12f312612345678LED2EA80C5112345678P1.0P1.1P1.2P1.3P1.4P1.5P1.6P1.7P2.5/A13P2.6/A14P2.7/A1527281011121314151617gP3.0/RXDP3.1/TXDP3.2/INT0P3.3/INT1P3.4/T0P3.5/T1P3.6/WRP3.7/RDBUT 百度搜索“77cn”或“免费范文网”即可找到本站免费阅读全部范文。收藏本站方便下次阅读，免费范文网，提供经典小说综合文库C51语言复习题参考答案88(4)在线全文阅读。
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