Now as far as i understand the state machine of Mr. Michael Karas is too lengthly and the same can be done in a simplified way in the following way and just liek to take opinion from you people if the following is the right way also or is there any problem in the following code for the same circuit as mentioned by
Mr. Michael Karas on

http://www.8052.com/forum/read.phtml?id=47505

looking forward for your comments



ORG 00H
JMP POWER_UP

ORG 0BH
JMP TOISR



ORG 030H
POWER_UP:
MOV A,#00H
MOV R0,#7FH
RAM_CLR:
MOV @RO,A
DJNZ R0,RAM_CLR ; Clearing the ram
MAIN:
CALL INIT
CALL SWCHK ;SWITCH CHECK
CALL LED
CALL COUNTER
CALL DEC
JMP MAIN

;*******************************************

INIT:
MOV IE,#10000010B ; timer 0 intrepput enabled
MOV TMOD,#01H
MOV TH0,#4EH
MOV TL0,#20H
SETB TR0

; ram location for counter of 5 seconds

MOV R0,#47H
COUNT: MOV @R0,#FBH
DEC R0
CJNE R0,#3FH,COUNT

;Ram location for LEDS which are on port0

MOV R0,#37H
MOV A,#01111111B
PORT0: MOV @R0,A
RR A
DEC R0
CJNE R0,#2FH,PORT0

;Ram location for buttons which are on P1

MOV R0,#2FH
MOV A,#10000000B
PORT1: MOV @R0,A
RR A
DEC R0
CJNE R0,#27H,PORT1
MOV R0,#27H
MOV R7,P1
RET

;******************************************

SWCHK:
MOV A,R7
RLC A
MOV R7,A

CJNE @R0,#02H,NEXT
RET

NEXT: JC END
MOV A,#01H
MOV @R0,A
RET


END: MOV A,#00H
MOV @R0,A
RET

:***************************************


LED:
CJNE @R0,#01H,END1
MOV A,R0
ADD A,#10H
MOV R1,A
MOV A,@R1
ANL P2,A
RET

END1:
MOV A,R0
ADD A,#08H
MOV R1,A
MOV A,@R1
ORL P2,A
RET

;***************************************************

COUNTER:
CJNE @R0,#01,END2
MOV A,R0
ADD A,#20H
MOV R1,A
MOV A,@R1
DEC A
MOV @R1,A
RET

END2:
MOV A,R0
ADD A,#20H
MOV R1,A
MOV @R1,0FBH
RET

;********************************************

DEC:
CJNE R0,#20H,DEC1
MOV R0,#27H
MOV R7,P1
RET

DEC1:
DEC R0
RET

;*********************************************

TOISR:
PUSH A
PUSH PSW
MOV TH0,#43H
MOV TL0,#20H
MOV R1,#47H

CHK_A: CJNE @R0,#FBH,CHK_B
DEC R1
CJNE R1,#3FH,CHK_A
POP PSW
POP A
RETI

CHK_B: MOV A,@R1
DJNZ A,CHK_C
MOV @R1,#FBH
MOV A,R1
CLR C
SUBB A,#20H
MOV R1,A
MOV @R1,#02H
MOV A,R1
ADD A,#20H
MOV R1,A
DEC R1
JMP CHK_A

CHK_C: MOV @R1,A
DEC R1
JMP CHK_A
END

************************************