ORG     0000H

LJMP    START

;---------------------------------

ORG     03H                   ;external interrupt 0

RETI

ORG     0BH                   ;timer 0 interrupt

RETI

ORG     13H                   ;external interrupt 1

RETI

ORG     1BH                   ;timer 1 interrupt

RETI

ORG     23H                   ;serial port interrupt

RETI

;=====================================

ORG     30H

;=====================================

KHOI_TAO:                     ;set up control registers

     MOV   TCON,#00H

     MOV   TMOD,#00H

     MOV   PSW,#00H            

     MOV   IE,#00H               ;disable interrupts

RET

;-------------------------------------

;HAM MAIN

;-------------------------------------

;ORG 30H

START:

        ACALL   KHOI_TAO        ;KHOI TAO CAC THANH GHI

        MOV     A,#6

        MOV     R3,A

        CJNE    A,#2,KTRA

        LJMP    NGTO

KTRA:

        MOV     R0,A

        MOV     R1,#2

NHAY:

        MOV     B,R1

        DIV     AB

        MOV     R2,B

        CJNE    R2,#0,TIEP

        JMP     BT

TIEP:

        INC     R1

        MOV     1DH,R1

        CJNE    A,1DH,NHAY

NGTO:

        MOV     P1,R3

        SJMP    KT

BT:

        MOV     P2,R3

KT:

        END

END