[Mecha]

Ví dụ đây là một "khung chương trình" của 89C52

;********************************************************
;*  Clock 24 MHz, 1 chu ky 0.5 us
;********************************************************

; Khai bao cac hang so khoi dong ban dau o day

; Khai bao bien o day

;-----------------------------
Start:
        mov   a,#0Ch
        da      a
        djnz    r0,$
        clr     EA
        clr     ET0
        clr     ET1
        clr     EX0
        clr     EX1
        jmp     Clear_RAM
;----------------------------------------------------------------------------
;                Clear RAM internal 20h - 0FFh for 89C52
;----------------------------------------------------------------------------
Clear_RAM:
        mov     r0,#20h
CLR_loop:
        mov     @r0,#0
        inc     r0
        cjne    r0,#0ffh,CLR_loop
        mov     sp,#Stack
;----------------------------------------------------------------------------
; Setup cac tham so khac o day

;--------------------------------------------------------
; Vong quet chuong trinh chinh
;--------------------------------------------------------
Main:
	jbc	flg_time.0,prg10us
n100us:
	jbc	flg_time.1,prg100us
n1ms:
	jbc	flg_time.2,prg1ms
n10ms:
	jbc	flg_time.3,prg10ms
n100ms:
	jbc	flg_time.4,prg100ms
n1sec:
	jbc	flg_time.5,prg1sec
n1minute:
	jmp	Main


;~~~~~~~~~~~~~~~~~~~~~~~~~~
prg10us:
	;cac lenh cua vong quet 10us
	jmp	n100us

;~~~~~~~~~~~~~~~~~~~~~~~~~~
prg100us:
	;cac lenh cua vong quet 100us
	jmp	n1ms

;~~~~~~~~~~~~~~~~~~~~~~~~~~
prg1ms:
	;cac lenh cua vong quet 1ms
	jmp	n10ms

;~~~~~~~~~~~~~~~~~~~~~~~~~~
prg10ms:
	;cac lenh cua vong quet 10ms
	jmp	n100ms

;~~~~~~~~~~~~~~~~~~~~~~~~~~
prg100ms:
	;cac lenh cua vong quet 100ms
	jmp	n1sec


;----------------------------------------------------------
; Thu tuc xu ly cac ngat
;----------------------------------------------------------

IntTimer0:
        push    0
        clr	   TR0		; cam timer 0
;cac lenh trong ngat Timer0
endtimer0:
        setb	TR0		; Cho phep timer 0
        pop	0
        reti

;----------------------------
;Tao chu ky vong quet khac nhau
IntTimer1:
        push    0
	clr	TR1		; cam timer 1

	setb	flg_time.0		;bit 0 : da thay doi 10us
	mov	r0,#cn_10us
	inc	@r0
	cjne	@r0,#10,endtimer1

	setb	flg_time.1		;bit 1: da thay doi 100us
	mov	@r0,#0
	mov	r0,#cn_100us
	inc	@r0
	cjne	@r0,#10,endtimer1

	setb	flg_time.2		;bit 2: da thay doi 1ms=1000us
	mov	@r0,#0
	mov	r0,#cn_1ms
	inc	@r0
	cjne	@r0,#10,endtimer1

	setb	flg_time.3		;bit 3: da thay doi 10ms
	mov	@r0,#0
	mov	r0,#cn_10ms
	inc	@r0
	cjne	@r0,#10,endtimer1

	setb	flg_time.4		;bit 4: da thay doi 100ms
	mov	@r0,#0
	mov	r0,#cn_100ms
	inc	@r0
	cjne	@r0,#10,endtimer1

	setb	flg_time.5		;bit 5: da thay doi 1sec=1000ms
	mov	@r0,#0
	mov	r0,#cn_1sec
	inc	@r0
	cjne	@r0,#60,endtimer1

	setb	flg_time.6		;bit 6: da thay doi 1minute=60s
	mov	@r0,#0
	mov	r0,#cn_1minute
	inc	@r0
	cjne	@r0,#60,endtimer1

	setb	flg_time.7		;bit 7: da thay doi 1hour=60minutes
	mov	@r0,#0
	mov	r0,#cn_1hour
	inc	@r0
	
endtimer1:
	mov	TL1,#Low(MotorPulse)
	mov	TH1,#High(MotorPulse)
	setb	TR1
	pop	0
	reti

;----------------------------
IntEx0:
        reti
;----------------------------
IntRS232:
        reti
;----------------------------
IntEx1:
        reti

;----------------------------
endprog: db ' End of program at here, bye!'
        END