51 single chip digital tube dynamic display program

    Experiment on the dynamic display program of the single-chip digital tube. The digital tube display is generally divided into two driving modes: static display and dynamic display. Static display occupies more lines. This article introduces how to realize the dynamic display of the digital tube. It should be said that the dynamic display of the digital tube is an important way for the external command output of the single-chip microcomputer. Therefore, how to design the digital tube and the working principle of the digital tube, the method of digital tube display, and the anti-interference design of the digital tube display occupy an important position in the design of the single-chip microcomputer system. This example designs a software query program and a software delay program (to prevent interference) based on the system hardware, and roughly describes the working principle and reading method of a dynamic display of a digital tube.

　　s1 bit p0.0 ; Digital tube bit definition
　　s2 bit p0.1
　　s3 bit p0.2
　　s4 bit p0.3
　　s5 bit p0.4
　　s6 bit p0.5
　　s7 bit p0.6
　　s8 bit p0.7

　　LED_data equ p2; digital tube data definition

　　org 00h ; program starts
　　jmp main ; main program starts at
　　30H org 030h ; main program starts at 30H
　　main: MOV sp,#30h ; set up the stack
　　lcall rest ; call the initialization program
　　lcall pro_8led ; call the digital tube display program
　　jmp main ; return

　　;************ Initialization procedure***************

　　rest:MOV a,#00h ; Clear register
　　MOV b,#00h ; Clear register
　　MOV p0,#0 ; Disable digital tube display
　　MOV p2,#255 ;
　　MOV p1,0ffh ; Disable LED display
　　clr beep ; Disable buzzer
　　ret ; Return

　　;******** Digital tube display program****************
　　pro_8led:
　　MOV b,#32; Display 32 digits in total
　　clr psw.3; Reset register group
　　setb psw.4;

　　MOV r0,#00h ;Data display starts from 0
　　MOV r1,#01h ;Digital tube starts from the 1st
　　loop:MOV p0,r1 ;Light up the current digital tube
　　MOV a,r0 ;Prepare the first data
　　MOV dptr,#tab_nu ;Get the table header
　　MOVc a,@a+dptr ;Get the first data
　　MOV led_data,a ;Output to the display data port

　　lcall delay ; 500 ms delay
　　lcall delay ; 1 s delay
　　inc r0 ; prepare the next data
　　MOV a, r1 ; prepare the next digital tube
　　rlc a ; set the next digital tube
　　jc c1 ; display all 8 bits, transfer
　　MOV r1, a ; otherwise, set the next digit
　　djnz b, loop ; 32 numbers are not displayed, return to display
　　ret ; otherwise return to the main program

　　c1: MOV r1,#1 ;After 8 bits are displayed, restart the loop
　　clr c ;Set the display bit
　　djnz b,loop ;After 32 bits are displayed, return to redisplay
　　ret ;Otherwise return to the main program
　　;************* Digital tube display***********************************

　　;**************** Software delay 500ms *****************************
　　delay: push psw ; Save the original register content
　　clr psw.3 ;
　　clr psw.4 ; Set a new register group
　　MOV r0,#2 ; Delay parameter 1
　　MOV r1,#250 ; Delay parameter 2
　　MOV r2,#2 ; Delay parameter 3
　　dl1:djnz r0,dl1 ; Delay loop 1
　　MOV r0,#250 ;
　　dl2:djnz r1,dl1 ; Delay loop 2
　　MOV r0,#240 ;
　　MOV r1,#248 ;
　　dl3:djnz r2,dl1 ; Delay loop 3
　　nop ; Timing accuracy adjustment
　　pop psw ; Restore the original register
　　ret ; Return
　　;******************************************************************

　　;**********************************************************
　　;This is a digital display table, where numbers with decimal points are 16 larger than numbers without decimal points
　　; For example, the display code for 0 is 0; then the display code for 0. is 16; and so on.

　　tab_nu:
　　db 0c0h, 0f9h, 0a4h, 0b0h, 99h , 92h , 82h, 0f8h ; Numbers 0-7 without decimal point codesdb
　　80h , 90h, 88h , 83h , 0c6h, 0a1h, 86h, 8eh ; Numbers 8-f without decimal point codesdb
　　40h , 79h, 24h , 30h , 19h , 12h , 02h, 78h ; Numbers 0-7 with decimal point codesdb
　　00h , 10h, 08h , 03h , 46h , 21h , 06h, 0eh ; Numbers 8-f with decimal point codes