;---------------------- Memory Allocate -------------------------------------
;*****************************************************************
;*                                                               *
;*   unlimited PWM Subroutines for the 8051 microcontroller      *
;*                   m suzatob aang c, 2005                      *
;*          4th floor b402-Electronic Engineering - ITS          *
;*                    surabaya indonesia                         *
;*  to add more pwm signal. just add memory value and port map   *
;*****************************************************************
;---------------------- memory map -----------------------------------------
PWM_swap		equ	7fh
PWM_skn			equ	7eh	;speed value of right motor
PWM_skr			equ	7dh	;speed value of left motor
;---------------------- port map -------------------------------------------
pwmkr			bit	p0.0
pwmkn			bit	p0.1
;---------------------- Zero Page ----------------------------------------

			org	0H		; Reset
			ljmp	Begin
;			org	03H		; INT 0
;			reti
			org	0BH		; Timer 0
			ljmp	PWM_msac
;			org	13H		; INT 1
;			reti
;			org	1BH		; Timer 1
;			reti
;			org	23H		; Port I/O Serial
;			reti


;---------------------- Begin -----------------------------------------------


			org	100H
begin:			mov	TMOD,#22h

 			mov	IE,#10010010b	;mengaktifkan interupt
			setb	TR0
			setb	TR1
			mov	P0,#0h
		
			clr	pwmkr		
			clr	pwmkr		
start:						
			mov	PWM_skr,#0ddh		;speed value of left motor
			mov	PWM_skn,#0ffh		;speed value of right motor
			

			sjmp	start
			
;---------------------- PWM Service --------------------------------

PWM_msac:		mov	PWM_swap,A
			mov	TH0,#0dch	;cc 60hz, dc 100hz xtall 11.059
			djnz	R7,Check
			setb	pwmkn
			setb	pwmkr
			reti
	Check:		xch	A,R7
			cjne	A,PWM_skn,Check1
			clr	pwmkn
	Check1:		cjne	A,PWM_skr,PWM_Ret
			clr	pwmkr
	PWM_Ret:	xch	A,R7
			mov	A,PWM_swap
			reti


			end