基于AT89c51单片机的超声波测距汇编语言源程序 -

VOUT EQU P1.0 ;脉冲输出端口
*中断入口程序*
ORG 0000H
LJMP START
ORG 0003H
LJMP PINT0
ORG 000BH
LJMP INTT0
ORG 0013H
RETI
ORG 001BH
LJMP INTT1
ORG 0023H
RETI
ORG 002BH
RETI
*主程序*
START: MOV SP, #4FH
MOV R0, #40H ;40~43H为显示数据存放单元（40为最高位）
MOV R7,#0BH
CLEARDISP:MOV @R0, #00H
INC R0
DJNZ R7, CLEARDISP
MOV 20H, #00H
MOV TMOD, #21H ;T1为8位自动重装模式，T0为16位定时器
MOV TH0, #00H ;65ms初值
MOV TL0, #00H ;40KHz初值
MOV TH1, #0F2H
MOV TL1, #0F2H
MOV P0, #0FFH
MOV P1, #0FFH
MOV P2, #0FFH
MOV P3, #0FFH
MOV R4, #04H ；超声波脉冲个数控制（为赋值的一半）
SETB PX0
SETB ET0
STEB EA
CLR 00H
SETB TR0 ;开启测距定时器
START1: LCALL DISPLAY
JNB 00H, START1 ;收到反射信号时标志位为1
CLR EA
LCALL WORK ；计算距离子程序
SETB EA
CLR 00H
SETB TR0 ；重新开启测距定时器
MOV R2, #64H ；测量间隔控制（约4*100=400ms）
LOOP: LCALL DISPLAY
DJNZ R2, LOOP
SJMP START 1
*中断程序*
;T0中断，65ms中断一次
INTT0: CLR EA
CLR TR0
MOV TH0, #00H
MOV TL0, #00H
SETB ET1
SETB EA
SETB TR0 ;启动计时器T0，用以计算超声波来回时间
SETB TR1 ;开启发超声波用定时器T1
OUT: RETI
;T1中断，发超声波用
INTT1: CPL VOUT
DJNZ R4,RETIOUT
CLR TR1 ；超声波发送完毕，关T1
CLR ET1
MOV R4,#04H
SETB EX0 ；开启接收回波中断
RETIOUT: RETI
;外中断0，收到回波时进入
PINT0: CLR TR0 ；关计数器
CLR TR1
CLR ET1
CLR EA
CLR EX0
MOV 44H, TL0 ；将计数值移入处理单元
MOV 45H, TH0
SETB 00H ；接收成功标志
RETI
*延时程序*
DL1MS: MOV R6, #14H
DL1: MOV R7, #19H
DL2: DJNZ R6, DL2
DJNZ R6, DL1
RET
*显示程序*
;40H为最高位，43H为最低位，先扫描高位
DISPLAY： MOV R1, #40H;G
MOV R5,#0F7H;G
PLAY: MOV A, R5
MOV P0, #0FFH
MOV P2, A
MOV A, @R1
MOV DPTR, #TAB
MOVC A, @A+DPTR
MOV P0, A
LCALL DLIMS
INC R1
MOV A, R5
JNB ACC.0, ENDOUT;G
RR A
MOV R5, A
AJMP PLAY
ENDOUT; MOV P2, #0FFH
MOV P0, #0FFH
RET
TAB; DB 0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H,0FFH,88H,0BFH
；共阳数码管 0 ,1, 2,3,4,5,6,7,8,9,不亮，A, —
*距离计算程序(=计算值×17/1000cm) 近似
WORK: PUSH ACC
PUSH PSW
PUSH B
MOV PSW, #18H
MOV R3, 45H
MOV R2, 44H
MOV R1, #00D
MOV R0, #17D
LCALL MUL2BY2
MOV R3, #03H
MOV R2, #0E8H
LCALL DIV4BY2
LCALL DIV4BY2
MOV 40H, R4
MOV A, 40H
JNZ JJ0
MOV 40H, #0AH ;最高位为0，不点亮
JJ0: MOV A R0
MOV R4, A
MOV A R1
MOV R5 A
MOV R3, #00D
MOV R2, #100D
LCALL DIV4BY2
MOV 41H, R4
MOV A, 41H
JNZ JJ1
MOV A, 40H ；此高位为0，先看最高位是否为不亮
SUBB A, #0AH
JNZ JJ1
MOV 41H, #0AH ；最高位不亮，次高位也不亮
JJ1: MOV A, R0
MOV R4, A
MOV A, R1
MOV R5, A
MOV R3, #00D
MOV R2, #10D
LCALL DIV4BY2
MOV 42H, R4
MOV A 42H
JNZ JJ2
MOV A, 41H ;次高位为0，先看次高位是否为不亮
SUBB A, #0AH
JNZ JJ2
MOV 42H, #0AH ；次高位不亮，次高位也不亮
JJ2: MOV 43H, R0
POP B
POP PSW
POP ACC
RET
*两字节无符号数乘法程序
MUL2BY2: CLR A
MOV R7, A
MOV R6, A
MOV R5, A
MOV R4, A
MOV 46H, #10H
MULLOOP1: CLR C
MOV A, R4
RLC A
MOV R4, A
MOV A, R5
RLC A
MOV R5, A
MOV A, R6
RLC A
MOV R6, A
MOV A, R7
RLC A
MOV R7, A
MOV A, R0
RLC A
MOV R0, A
MOV A, R1
RLC A
MOV R1, A
JNC MULLOOP2
MOV A, R4
ADD A, R2
MOV R4, A
MOV A, R5
ADDC A, R3
MOV R5, A
MOV A, R6
ADDC A, #00H
MOV R6, A
MOV A, R7
ADDC A, #00H
MOV R7, A
MULLOOP2: DJNZ 46H, MULLOOP1
RET
*四字节/两字节无符号数除法程序*
DIV4BY2: MOV 46H, #20H
MOV R0, #00H
MOV R1, #00H
DIVLOOP1: MOV A, R4
RLC A
MOV R4, A
MOV A, R5
RLC A
MOV R5, A
MOV A, R6
RLC A
MOV R6, A
MOV A, R7
RLC A
MOV R7, A
MOV A, R0
RLC A
MOV R0, A
MOV A, R1
RLC A
MOV R1, A
CLR C
MOV A, R0
SUBB A, R2
MOV B, A
MOV A, R1
SUBB A, R3
JC DIVLOOP2
MOV R0, B
MOV R1, A
DIVLOOP2: CPL C
DJNZ 46H, DIVLOOP1
MOV A, R4
RLC A
MOV R4, A
MOV A, R5
RLC A
MOV R5, A
MOV A, R6
RLC A
MOV R6, A
MOV A, R7
RLC A
MOV R7, A
RET
;
END
附C51程序
#INCLUDE <REG51.H>
#DEFINE UCHAR UNSIGNED CHAR
#DEFINE UINT UNSIGNED INT
#DEFINE ULONG UNSIGNED LONG
EXTERN VOID CS_T(VOID);
EXTERN VOID DELAY(UINT);
EXTERN VOID DISPLAY(UCHAR*);
//DATA UCHAR DISPLAY(UCHAR*);
DATA UCHAR TESTOK;
VOID MAIN (VOID)
{
DATA UCHAR DISPRAM[5];
DATA UINT I;
DATA ULONG TIME;
P0=0XFF;
P2=0XFF;
TMOD=0X11;
IE=0X80;
WHILE (1)
{
CS_T();
DELAY(1);
TESTOK=0;
EX0=1;
ET0=1;
WHILE(! TESTOK) DISPLAY(DISPRAM);
IF (1==TESTOK)
{
TIME=TH0;
TIME=(TIME<<8)| TL0;
TIME*=172;
TIME/=10000;
DISPRAM[0]=(UCHAR) (TIME%10);
TIME/=10;
DISPRAM[1]=(UCHAR) (TIME%10);
TIME/=10;
DISPRAM[2]=(UCHAR) (TIME%10);
DISPRAM[3]=(UCHAR) (TIME/10);
IF (0==DISPRAM[3]) DISPRAM[3]=17;
} ELSE
{
DISPRAM [0]=16;
DISPRAM [1]=16;
DISPRAM [2]=16;
DISPRAM [3]=16;
}
FOR (I=0;I<300;I++) DISPLAY(DISPRAM);
}
}
VOID CS_R(VOID) INTERRUPT 0
{
TR0=0;
ET0=0;
EX0=0;
TESTOK=1;
}
VOID OVERTIME(VOID) INTERRUPT 1
{
EX0=0;
TR0=0;
ET0=0;
TESTOK=2;
}
NAME CS_T
?PR?CS_T?CS_T SEGMENT CODE
PUBLIC CS_T
RSEG ?PR?CS_T?CS_T
CS_T: PUSH ACC
MOV TH0, #00H
MOV TL0, #00H
MOV A, #4D
SETB TR0
CS_T1: CPL p1.0
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
DJNZ ACC,CS_T1
POP ACC
RET
;
END
NAME DELAY
?PR?_DELAY?DELAY SEGMENT CODE
PUBLIC _DELAY
RSEG ?PR?_DELAY?DELAY
_DELAY: PUSH ACC
MOV A,R7
JZ DELA1
INC R6
DELA1: MOV R5,#50D
DJNZ R5, $
DJNZ R7,DELA1
DJNZ R6,DELA1
POP ACC
RET
END
NAME DISPLAY
?PR?_DISPLAY?DISPLAY SEGMENT CODE
?CO?_DISPLAY?DISPLAY SEGMENT DATA
EXTRN CODE (_DELAY)
PUBLIC _DISPLAY
RSEG ?CO?_DISPLAY?DISPLAY
?_DISPLAY?BYTE:
DISPBIT: DS 1
DISPNUM: DS 1
RSEG ?PR?_DISPLAY?DISPLAY
_DISPLAY: PUSH ACC
PUSH DPH
PUSH DPL
PUSH PSW
INC DISPNUM
MOV A,DISPNUM
CJNE A,#4D,DISP1
DISP1: JC DISP2
MOV DISPNUM,#00H
MOV DISPBIT,#0FEH
DISP2: MOV A,R1
ADD A,DISPNUM
MOV R0,A
MOV A,@R0
MOV DPTR,#DISPTABLE
MOVC A,@A+DPTR
MOV P0,A
MOV A,DISPNUM
CJNE A,#2D,DISP3
CLR P0.7
DISP3: MOV P2,DISPBIT
MOV R5,#00H
MOV R7,#0AH
LCALL _DELAY
MOV P0,#0FFH
MOV P2,#0FFH
MOV A,DISPBIT
RL A
MOV DISPBIT,A
POP PSW
POP DPL
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