Hi Hatem,
I simulated the program michael put on and found it to work well.
Regards,
Charles Bannister

;;*********************************************************************
;; SIX DIGIT UP/DOWN COUNTER COUNTER
;; http://www.8052.com/forum/read.phtml?id=59695
;; assemble A51 filename.asm
;;*********************************************************************
.EQU	DIGITS1,  0x14       ;; ram memory LSB
.EQU    DIGITS2,  0x15       ;;  
.EQU    DIGITS3,  0x16       ;; 
.EQU    DIGITS4,  0x17       ;; 
.EQU    DIGITS5,  0x18       ;; 
.EQU    DIGITS6,  0x19       ;; ram memory MSB 
.ORG 0H
ljmp start
.org 100h
start:
     MOV DIGITS1, #00
     MOV DIGITS2, #00
     MOV DIGITS3, #00
     MOV DIGITS4, #00
     MOV DIGITS5, #00
     MOV DIGITS6, #00
start2:     
     acall  cntup
     mov   a, digits6
     cjne  a, #0x0A, start3
start3:
     jc start2			;; < 999999     
stop1:
     sjmp stop1     
CNTUP:
     MOV   R0, #DIGITS1
     MOV   R2, #6
CNTLP:
     INC   @R0
     CJNE  @R0, #10, CNTCT
CNTCT:
     JC    CNTDN
     MOV   @R0, #0  		;; increment 6 digits upward
     INC   R0
     DJNZ  R2, CNTLP
     RET
CNTDN:
     RET
.END	
:03000000020100FA
:1001000075140075150075160075170075180075C3
:100110001900311DE519B40A0040F780FE78147A01
:0E0120000606B60A004006760008DAF522222E
:00000001FF