单片机试题库程序及答案

1、程序功能通过用DAC0832产生三角波。（DAC0832的数字信号输入端接P0口，/CS接P27，/XFER接地，/WR1、/WR2接单片机的/WR，ILE接电源5V。）DA0832IFORI255I0IFORI0IINCLUDE/存放绝对地址宏定义的函数原型INCLUDEDEFINEUCHARUNSIGNEDCHARDEFINEUINTUNSIGNEDINTDEFINEDA0832XBYTE0X7FFFVOIDDELAY_1MSTH10XFCTL10X18TR11WHILETF1/等待1MS定时时间到TF10VOIDMAINUCHARITMOD0X10WHILE1FORI0I0IDA0832I/D/A转换输出DELAY_1MS2、程序功能通过DAC0832产生锯齿波。（DAC0832的数字信号输入端接P0口，/CS接P27，/XFER接地，/WR1、/WR2接单片机的/WR，ILE接电源5V。）选择项DELAY_1MSDA0832IFORI0I源程序INCLUDE/存放绝对地址宏定义的函数原型INCLUDEDEFINEUCHARUNSIGNEDCHARDEFINEUINTUNSIGNEDINTDEFINEDA0832XBYTE0X7FFFVOIDDELAY_1MSTH10XFCTL10X18TR11WHILETF1TF10VOIDMAINUCHARITMOD0X10WHILE1FORI0I23IFTIME159IFTIME059P0DISPCODETIMEI/10P0DISPCODETIMEI10FORI0I0KVOIDDISPLAYVOID/显示函数UCHARI,KK0X01/设置位选线初值FORI0I59/秒是否超过59TIME00/秒清0TIME1/分加1IFTIME159/分是否超过59TIME10/分清0TIME2/小时加1IFTIME223/小时是否超过23TIME20/小时清0VOIDMAIN（）/主函数UCHARIWHILE1/无限循环FORI0I3I0DELAY10/一曲结束，重新开始播放VOIDTIMEINTERRUPT3/T1中断服务程序TH1TH/定时器重置初值（高位）TL1TL/定时器重置初值（低位）P1_3P1_3/输出取反5、程序功能设置八个电子琴键（从P1口接入），能够通过按键发出相应的声音（弹奏）。利用单片机的定时器T0实现声音频率的产生（P33引脚接蜂鸣器）。选择项CASE0X7FCASE0XFESWITCHIWHILE1TCON0X10TMOD0X01MAINP3_3P3_3VOIDINTTOINTERRUPT1SBITP3_3P33源程序INCLUDE“REG52H“/头文件SBITP3_3P33/定义蜂鸣器输出引脚UNSIGNEDCHARIDATAI,TL0_TEMP0,TH0_TEMP0/定义全局变量VOIDINTTOINTERRUPT1/T0服务程序TH0TH0_TEMP/定时器重置初值（高位）TL0TL0_TEMP/定时器重置初值（低位）P3_3P3_3/输出取反MAIN/主函数P10XFF/端口初始化TMOD0X01/定时器工作方式设置ET01/T0中断允许设置EA1/中断总允许设置TH00/定时初值高位设置TL00/定时初值低位设置TCON0X10/定时器启动设置WHILE1/无限循环IP1/读端口值SWITCHICASE0XFFTR00BREAK/无键按下CASE0XFETH0_TEMP0XFCTL0_TEMP0X43TR01BREAK/1键按下CASE0XFDTH0_TEMP0XFCTL0_TEMP0XABTR01BREAK/2键按下CASE0XFBTH0_TEMP0XFDTL0_TEMP0X08TR01BREAK/3键按下CASE0XF7TH0_TEMP0XFDTL0_TEMP0X32TR01BREAK/4键按下CASE0XEFTH0_TEMP0XFDTL0_TEMP0X81TR01BREAK/5键按下CASE0XDFTH0_TEMP0XFDTL0_TEMP0XC7TR01BREAK/6键按下CASE0XBFTH0_TEMP0XFETL0_TEMP0X05TR01BREAK/7键按下CASE0X7FTH0_TEMP0XFETL0_TEMP0X21TR01BREAK/8键按下DEFAULTTR00BREAK/多键按下6、程序功能单片机控制两个共阳数码管实现计数显示（P0口接段码，P20口接十位数码管的位码，P21口接个位数码管的位码）。外中断0每触发一次，计数值加1；外中断1每触发一次，计数值减1。选择项IFA99VOIDINT0VOIDINTERRUPT0DIAPLAYA/10A10P20X02P20X01VOIDDIAPLAYVOID源程序INCLUDE/头文件UNSIGNEDCHARTABLE100XC0,0XF9,0XA4,0XB0,0X99,0X92,0X82,0XF8,0X80,0X90/定义共阳数码管09显示码数组UNSIGNEDCHARDATA_L,DATA_H/定义全局变量显示个位、十位CHARA0/定义全局变量计数初值VOIDDELAYUNSIGNEDCHARK/延时函数UNSIGNEDCHARM,NFORM0M99A0/计数值过大，清零ELSEA/计数值加1VOIDINT1VOIDINTERRUPT2/外部中断1函数IFAUNSIGNEDCHARAUNSIGNEDCHARM,NIE0X85TCON0X05WHILE1P0AVOIDINT0VOIDINTERRUPT0VOIDINT1VOIDINTERRUPT2A_CROR_A,1源程序INCLUDE/头文件INCLUDE/包含循环移位函数的头文件UNSIGNEDCHARA/定义全局变量VOIDDELAYUNSIGNEDCHARK/延时函数UNSIGNEDCHARM,NFORM0M/头文件UNSIGNEDCHARMOTO_PAI80XF1,0XF3,0XF2,0XF6,0XF4,0XFC,0XF8,0XF9/单双相正转UNSIGNEDCHARPAI_NUM/状态号SBITCFP30/开关设置VOIDTIMERVOIDINTERRUPT1USING1/T0中断服务程序TH06553660000/256/定时器重置初值（高位）TL06553660000256/定时器重置初值（低位）IFCF0/开关闭合PAI_NUM/状态号加1IFPAI_NUM8PAI_NUM0/若状态号过大，回零ELSE/开关断开IFPAI_NUM0I源程序INCLUDE/头文件DEFINEUCHARUNSIGNEDCHARUCHARCODETAB10X01,0X02,0X04,0X08/单相正转加电代码UCHARCODETAB20X03,0X06,0X0C,0X09/双相正转电代码UCHARCODETAB30X01,0X03,0X02,0X06,0X04,0X0C,0X08,0X09/单双相正转VOIDDELAY/延时函数LONGIFORI0I0IP2TAB1IDELAYBREAK/单步4拍反走CA