超声波测距汇编程序

;///////////////////////////////////////////////////////;USEBY:超声波测距器;测距范围xxCM-yyCM,堆栈在4FH以上，20H用于标志；显示缓冲单元在40H-43H,使用内存44H、45H、46H用于计算距离VOUTEQUP1.0 ;红外脉冲输出端口speakequp1.1;喇叭输出端口;*中断入口程序*ORG0000HLJMPSTARTORG0003HLJMPPINT0ORG000BHretiORG0013HRETIORG001BHLJMPINTT1ORG0023HRETIORG002BHRETI;*主程序;*START:MOVMOVSP,#4FHR0,#40H；40H-43H为显示数据存放单兀（40H为最高位）MOVR7,#0BHCLEARDISP:MOV@R0,#00HINCR0DJNZR7,CLEARDISPMOV20H,#00HMOVTMOD,#11H;T1/T0为16位定时器MOVTH0,#00H;65毫秒初值MOVTL0,#00HMOVTH1,#00HMOVTL1,#00HMOVP0,#0FFHMOVP1,#0FFHMOVP2,#0FFHMOVP3,#0FFHMOVR4,#04HSETBPX0SETBET1SETBEASETBTR1;超声波脉冲个数控制（为赋值的一半）;开启测距定时器start1:LCALLDISPLAYJNB00H,START1CLREALCALLWORKclrEAMOVR2,#32h;#64H

;收到反射信号时标志位为1;计算距离子程序;测量间隔控制（约4*100=400MS）LOOP:LCALLDISPLAYDJNZ R2,LOOPCLR 00Hsetbet0mov th0,00hmov tl0,00hSETB TR1 ;重新开启测距定时器SETB EASJMPStart1;*中断程序* *;T1中断，发超声波用;T1中断，65毫秒中断一次INTT1:CLREACLRTR0clrex0MOVTH0,#00HMOVTL0,#00HMOVTH1,#00HMOVTL1,#00HSETBET0SETBEASETBTRO ;启动计数器TO,用以计数intt11:CPLnopnopnopnopVOUT ;40KHZ

nopnopnopnopnopDJNZR4,intt11;超声波发送完毕，MOVR4,#04H ;只发送了两个周期lcalldelay_250;延时，避开发射的直达声波信号SETBEX0 ;开启接收回波中断RETIOUT:RETI;外中断0PINT0:收到回波时进入;外中断0PINT0:收到回波时进入nopjbp3.2,pint0_exitCLRTR0;关计数器CLREA\CLREX0\MOV44H,TL0;将计数值移入处理单元MOV45H,TH0\movth0,#00hmovtl0,#00hjnbp3.2,$SETB00H;接收成功标志pint0_exit:RETI;*、显示程序;*、；40H为最高位，43H为最低位，先扫描高位DISPLAY:MOVR1,#40H;GMOVR5,#7fH;GPLAY:MOVA,R5MOVP0,#0FFHMOVP2,AMOVA,@R1MOVDPTR,#TABMOVCA,@A+DPTRMOVP0,ALCALLDL1MSINCR1MOVA,R5JNBACC.4,ENDOUT;GRRAMOVR5,AAJMPPLAY

ENDOUT:MOVP2,#0FFHMOVP0,#0FFHRETTAB:DB18h,7Bh,2Ch,29h,4Bh,89h,88h,3Bh,08h,09h,0ffh;共阳段码表"0""1""2" "3""4""5""6""7""8""9""不亮""A""-";*延时程序（1ms） *DL1MS:push 06hpush 07hMOV R6,#14HDL1:MOVR7,#19HDL2:DJNZR7,DL2DL2:DJNZR7,DL2DJNZR6,DL1pop07hpop06hRET； 距离计算程序（=计数值*17/1000cm） *work:PUSHACCPUSHPSWPUSHBMOVPSW,#18hMOVR3,45HMOVR2,44HMOVR1,#00DMOVR0,#17DLCALLMUL2BY2MOVR3,#03HMOVR2,#0E8HLCALLDIV4BY2LCALLDIV4BY2MOV40H,R4MOVA,40H;最高位为零，不点亮;最高位为零，不点亮MOV40H,#0AHJJ0:MOVA,R0MOVR4,AMOVA,R1MOVR5,A

MOVR3,#00DMOVR2,#100DLCALLDIV4BY2JJ1:JJ2:MOV41H,R4JJ1:JJ2:MOVA,41HJNZJJ1MOVA,40H ;次高位为0，先看最高位是否为不亮SUBBA,#0AHJNZJJ1MOV41H,#0AH;最高位不亮，次高位也不亮MOVA,R0MOVR4,AMOVA,R1MOVR5,AMOVR3,#00DMOVR2,#10DLCALLDIV4BY2MOV42H,R4MOVA,42HJNZJJ2MOVA,41H ;次次高位为0，先看次高位是否为不亮SUBBA,#0AHJNZJJ2MOV42H,#0AH;次高位不亮，次次高位也不亮MOV43H,R0POPBPOPPSWPOPACCRET;*两字节无符号数乘法程序*;R7R6R5R4<=R3R2*R1R0MUL2BY2:CLRAMOVR7,AMOVR6,AMOVR5,AMOVR4,AMOV46H,#10HMULLOOP1:CLRCMOVA,R4RLCAMOVR4,AMOVA,R5

RLCAMOVR5,AMOVA,R6RLCAMOVR6,AMOVA,R7RLCAMOVR7,AMOVA,R0RLCAMOVR0,AMOVA,R1RLCAMOVR1,AJNCMULLOOP2MOVA,R4ADDA,R2MOVR4,AMOVA,R5ADDCA,R3MOVR5,AMOVA,R6ADDCA,#00HMOVR6,AMOVA,R7ADDCA,#00HMOVR7,AMULLOOP2:DJNZ46H,MULLOOP1RET;* 四字节/两字节无符号数除法程序 *; R7R6R5R4/R3R2=R7R6R5R4（商）...R1R0（余数）DIV4BY2:MOV46H,#20HMOVR0,#00HMOVR1,#00HDIVLOOP1:MOVA,R4RLCAMOVR4,AMOVA,R5RLCAMOVR5,AMOVA,R6RLCA

MOVR6,AMOVA,R7RLCAMOVR7,AMOVA,R0RLCAMOVR0,AMOVA,R1RLCAMOVR1,ACLRCMOVA,R0SUBBA,R2MOVB,AMOVA,R1SUBBA,R3JCDIVLOOP2MOVR0,BMOVR1,ADIVLOOP2:CPLCDJNZ46H,DIVLOOP1MOVA,R4RLCAMOVR4,