基于单片机的脉冲宽度测量

山东科技大学电工电子实验教学中心创新性实验研究报告

课程名称：单片机原理及应用

实验项目名称脉冲宽度测量

姓名学号_________________

专业_____________ 班级____________

指导教师及职称________________________

开课学期2011 至2012 学年第一学期

提交时间2012 年 1 月 3 日

五、实验结果与分析

1、实验现象、数据记录

按照流程图所示，按动脉冲按钮，可以看到，显示屏显示出所测脉冲的宽度。再次按动，可以清楚地观察到所示的示数变化。每次显示的示数，都根据所按按钮的时间长短，即高电平的脉宽长度。

第一张图为T0工作方式，第二张图为T2捕捉方式。

六、实验结论

七、指导老师评语及得分：

附件：源程序等。

T0门控方式：

ORG 0000H

LJMP MAIN

ORG 000BH

LJMP T0_INT

ORG 0030H MAIN: MOV TMOD,#09H

MOV TL0,#0FCH

MOV TH0,#17H

MOV R4,#00H

MOV R3,#00H

JB P3.2,$

SETB ET0

SETB EA

IOC: SETB TR0

JNB P3.2,$

MOV R3,#00H

MOV R4,#00H

JB P3.2,$

CLR TR0

MOV 34H,R4

MOV 35H,R3

LCALL BCD

LCALL UBCD DIS: LCALL DISP

JB P3.2,IOC

SJMP DIS

T0_INT:INC R3

CJNE R3,#00H,NEXT

INC R4

NEXT: MOV TH0,#0FCH

MOV TL0,#17H

RETI

BCD: MOV R7,#16

CLR A

MOV 47h,A

MOV 46h,A

MOV 45h,A

BCD1:CLR C

MOV A,35H

RLC A

MOV 35H,A

MOV A,34H

RLC A

MOV 34H,A

MOV A,47H

ADDC A,47H

DA A

MOV 47H,A

MOV A,46H

ADDC A,46H

DA A

MOV 46H,A

MOV A,45H

ADDC A,45H

DA A

MOV 45H,A

DJNZ R7,BCD1

RET

UBCD:MOV A,45H

ANL A,#0F0H

SWAP A

MOV 50H,A

MOV A,45H

ANL A,#0FH

MOV 51H,A

MOV A,46H

ANL A,#0F0H

SWAP A

MOV 52H,A

MOV A,46H

ANL A,#0FH

MOV 53H,A

MOV A,47H

ANL A,#0F0H

SWAP A

MOV 54H,A

MOV A,47H

ANL A,#0FH

MOV 55H,A

RET

DISP:MOV R0,#55H

MOV R2,#20H

MOV A,#0FFH

MOV P0,A

ACALL DIP

MOV R0,#54H MOV R2,#10H ACALL DIP

MOV R0,#53H MOV R2,#08H ACALL DIP

MOV R0,#52H MOV R2,#04H MOV A,R2

MOV P2,A

MOV A,@R0

MOV DPTR,#TABLE MOVC A,@A+DPTR ANL A,#7FH

MOV P0,A

ACALL DELAY MOV R0,#51H MOV R2,#02H ACALL DIP

MOV R0,#50H

MOV R2,#01H

ACALL DIP

RET

DIP:MOV A,R2

MOV P2,A

MOV A,@R0

MOV DPTR,#TABLE

MOVC A,@A+DPTR

MOV P0,A

ACALL DELAY

RET

DELAY:

MOV R5,#9FH

DJNZ R5,$

RET

TABLE:DB

0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H ,80H,90H,88H,83H,0C6H,0A1H,86H,8EH END

T2捕捉方式：

T2CON EQU 0C8H

TH2 EQU 0CDH

TL2 EQU 0CCH

RCAP2H EQU 0CBH

RCAP2L EQU 0CAH

TR2 BIT 0CAH

ORG 0000H

LJMP MAIN

ORG 000BH

LJMP T0_INT

ORG 0030H MAIN: MOV TMOD, #01H

MOV T2CON,#0FH

JB P1.1,$

STR: MOV TL0, #17H

MOV TH0, #0FCH

MOV TH2, #00

MOV TL2 ,#00

MOV 50H,#00H

MOV 51H,50H

CLR P1.0

SETB EA

SETB ET0

JNB P1.1, $

SETB TR0

SETB TR2

JB P1.1, $

CLR TR0

MOV 50H,RCAP2L

MOV 51H,RCAP2H

LCALL ZHUANHUAN LOOP1: LCALL DISP

JB P1.1,STR

AJMP LOOP1

T0_INT: MOV TL0, #17H

MOV TH0, #0FCH

SETB P1.0

NOP

NOP

CLR P1.0

RETI ZHUANHUAN: CLR A

MOV 38H,51H

MOV 37H,50H

MOV 34H,#0

MOV 35H,#0

MOV 36H,#0

MOV R7,#16 LOOP2: CLR C

MOV A,37H

RLC A

MOV 37H ,A

MOV A,38H

RLC A

MOV 38H ,A

MOV A,36H

ADDC A,36H

DA A

MOV 36H,A

MOV A,35H

ADDC A,35H

DA A

MOV 35H,A

MOV A,34H

ADDC A,34H

DA A

MOV 34H,A

DJNZ R7 ,LOOP2

MOV R1,#35H

MOV R0,#36H

MOV A,#00

XCHD A,@R0

MOV 58H,A

MOV A,@R0

SWAP A

MOV 57H,A

MOV A,#00

XCHD A,@R1

MOV 56H,A

MOV A,@R1

SWAP A

MOV 55H,A

MOV A,#00

MOV R0,#34H

XCHD A,@R0

MOV 54H,A

MOV A,@R0

SWAP A

MOV 53H,A

RET

DISP: MOV R0,#53H

MOV R2,#01H

LOP11: MOV A,#0FFH

MOV P0,A

MOV A,R2

MOV P2,A

MOV A,@R0

MOV DPTR,#TAB

MOVC A,@A+DPTR

CJNE R0,#55H,LOP21

ANL A,#7FH

LOP21: MOV P0,A

ACALL DELAY

INC R0

MOV A,R2

JB ACC.5,EXIT1

RL A

MOV R2,A

AJMP LOP11

EXIT1: RET

DELAY: MOV R7,#0FEH

LOOP: MOV R6,#70H

DJNZ R7,LOOP

RET

TAB:DB

0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8 H,80H,90H,88H,83H,0C6H,0A1H,86H,8EH END