mc_16f72.asm

pic application note code

;*******************************************************************************
;THIS ROUTINE UPDATES THE OFFSET POINTERS TO THE TABLE AFTER EVERY ACCESS
;*******************************************************************************
UPDATE_TABLE_OFFSET
	bcf		STATUS,RP0
	btfss	FLAGS,OFFSET1_FLAG		;IF SET INCR. ON TABLE
	goto	DECREMENT_OFFSET1
	movlw	(SINE_TABLE_ENTRIES-1)		;CHECK FOR THE LAST VALUE ON THE TABLE
	SUBWF	TABLE_OFFSET1,W
	btfsc	STATUS,C	
	goto	CLEAR_OFFSET1_FLAG
	INCF	TABLE_OFFSET1,F			;INCREMENT OFFSET1
	goto	UPDATE_OFFSET2
CLEAR_OFFSET1_FLAG
	bcf	FLAGS,OFFSET1_FLAG
DECREMENT_OFFSET1
	DECFSZ	TABLE_OFFSET1,F			;DECREMENT OFFSET1
	goto	UPDATE_OFFSET2
	bsf		FLAGS,OFFSET1_FLAG

UPDATE_OFFSET2
	btfss	FLAGS,OFFSET2_FLAG		;IF SET INCR. ON TABLE
	goto	DECREMENT_OFFSET2
	movlw	(SINE_TABLE_ENTRIES-1)		;CHECK FOR THE LAST VALUE ON THE TABLE
	SUBWF	TABLE_OFFSET2,W
	btfsc	STATUS,C
	goto	CLEAR_OFFSET2_FLAG
	INCF	TABLE_OFFSET2,F			;INCREMENT OFFSET2
	goto	UPDATE_OFFSET3
CLEAR_OFFSET2_FLAG
	bcf	FLAGS,OFFSET2_FLAG
DECREMENT_OFFSET2
	DECFSZ	TABLE_OFFSET2,F			;DECREMENT OFFSET2
	goto	UPDATE_OFFSET3
	bsf	FLAGS,OFFSET2_FLAG

UPDATE_OFFSET3
	btfss	FLAGS,OFFSET3_FLAG		;IF SET INCR. ON TABLE
	goto	DECREMENT_OFFSET3
	movlw	(SINE_TABLE_ENTRIES-1)		;CHECK FOR THE LAST VALUE ON THE TABLE
	SUBWF	TABLE_OFFSET3,W
	btfsc	STATUS,C
	goto	CLEAR_OFFSET3_FLAG
	INCF	TABLE_OFFSET3,F			;INCREMENT OFFSET3
	RETURN	
CLEAR_OFFSET3_FLAG
	bcf	FLAGS,OFFSET3_FLAG
DECREMENT_OFFSET3
	DECFSZ	TABLE_OFFSET3,F			;DECREMENT OFFSET3
	RETURN
	bsf	FLAGS,OFFSET3_FLAG
	RETURN	


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

CALCULATE_NEW_SPEED
	movf	NEW_FREQ,W
	movwf	MOTOR_FREQUENCY
	movlw	0x22			
	addwf	MOTOR_FREQUENCY,F
	bcf		STATUS,C
	rrf		MOTOR_FREQUENCY,F
	bcf		STATUS,C
	rrf		MOTOR_FREQUENCY,F
	movlw	0xB5			
	addwf	MOTOR_FREQUENCY,F
	return	

;*************************************************************************
;PWMs are arranged from low duty cycle to high duty cycle 
;Original duty cycles are input to routine on PWMx_DS
;Output on PWM_PRx and PWM_PR_CHx 
PRIORATIZE_PWMS

	movlw	0x1
	movwf	PWM_PR_CH1_Buff
	movlw	0x2
	movwf	PWM_PR_CH2_Buff	
	movlw	0x4
	movwf	PWM_PR_CH3_Buff

	movf	PWM1_DS_Buff,W
	subwf	PWM2_DS_Buff,W
	btfss	STATUS,C
	goto	INTCHG_1_2
	goto	CHECK_2_3
INTCHG_1_2
;interchange duty cycles in 1 and 2
	movf	PWM1_DS_Buff,W
	movwf	TEMP_LOC
	movf	PWM2_DS_Buff,W
	movwf	PWM1_DS_Buff
	movf	TEMP_LOC,W
	movwf	PWM2_DS_Buff
;interchange the PWM outputs
	movf	PWM_PR_CH1_Buff,W
	movwf	TEMP_LOC
	movf	PWM_PR_CH2_Buff,W
	movwf	PWM_PR_CH1_Buff
	movf	TEMP_LOC,W
	movwf	PWM_PR_CH2_Buff

CHECK_2_3
;interchange duty cycles in 2 and 3
	movf	PWM2_DS_Buff,W
	subwf	PWM3_DS_Buff,W
	btfss	STATUS,C
	goto	INTCHG_2_3
	goto	CHECK_1_2_AGN
INTCHG_2_3
	movf	PWM2_DS_Buff,W
	movwf	TEMP_LOC
	movf	PWM3_DS_Buff,W
	movwf	PWM2_DS_Buff
	movf	TEMP_LOC,W
	movwf	PWM3_DS_Buff
;interchange the PWM outputs pins
	movf	PWM_PR_CH2_Buff,W
	movwf	TEMP_LOC
	movf	PWM_PR_CH3_Buff,W
	movwf	PWM_PR_CH2_Buff
	movf	TEMP_LOC,W
	movwf	PWM_PR_CH3_Buff

CHECK_1_2_AGN
;interchange duty cycles in 1 and 2
	movf	PWM1_DS_Buff,W
	subwf	PWM2_DS_Buff,W
	btfss	STATUS,C
	goto	INTCHG_1_2_AGN
	goto	CALCULATE_TIMER_RELOAD
INTCHG_1_2_AGN
	movf	PWM1_DS_Buff,W
	movwf	TEMP_LOC
	movf	PWM2_DS_Buff,W
	movwf	PWM1_DS_Buff
	movf	TEMP_LOC,W
	movwf	PWM2_DS_Buff
;interchange the PWM outputs pins
	movf	PWM_PR_CH1_Buff,W
	movwf	TEMP_LOC
	movf	PWM_PR_CH2_Buff,W
	movwf	PWM_PR_CH1_Buff
	movf	TEMP_LOC,W
	movwf	PWM_PR_CH2_Buff

CALCULATE_TIMER_RELOAD
	movlw	0x9C			;Corresponding to 8KHz count with Timer1 prescale 1:4
	movwf	PWM4_DS_Buff	
	movf	PWM3_DS_Buff,W	
	subwf	PWM4_DS_Buff,F
	movf	PWM2_DS_Buff,W	
	subwf	PWM3_DS_Buff,F
	movf	PWM1_DS_Buff,W	
	subwf	PWM2_DS_Buff,F

	RETURN	


;*******************************************************************************
;This routine checks for the keys status. 2 keys are checked, Run/Stop and 
;Forward(FWD)/Reverse(REV)  
;*******************************************************************************
KEY_CHECK
	btfss	KEY_PORT,RUN_STOP_KEY			;Is key pressed "RUN/STOP"?
	goto	CHECK_FWD_REV_KEY
	btfsc	FLAGS1,DEBOUNCE
	return
	call	KEY_DEBOUNCE
	btfss	FLAGS1,DEBOUNCE
	return
	bsf		FLAGS1,KEY_RS
	return
	
CHECK_FWD_REV_KEY
	btfss	KEY_PORT,FWD_REV_KEY			;Is key pressed "RUN/STOP"?
	goto	SET_KEYS
	btfsc	FLAGS1,DEBOUNCE
	return
	call	KEY_DEBOUNCE
	btfss	FLAGS1,DEBOUNCE
	return
	bsf		FLAGS1,KEY_FR
	return

SET_KEYS
	btfss	FLAGS1,DEBOUNCE
	return
	bcf		FLAGS1,DEBOUNCE
	bsf		FLAGS1,KEY_PRESSED	
	btfss	FLAGS1,KEY_RS
	goto	ITS_FWD_REV	
	btfss	FLAGS1,RUN_STOP			;Toggle RUN_STOP bit
	goto	$+3
	bcf		FLAGS1,RUN_STOP
	return
	bsf		FLAGS1,RUN_STOP
	return

ITS_FWD_REV	
	btfss	FLAGS1,FWD_REV			;Toggle RUN_STOP bit
	goto	$+3
	bcf		FLAGS1,FWD_REV
	return
	bsf		FLAGS1,FWD_REV
	return

;*******************************************************************************
KEY_DEBOUNCE
	decfsz	DEBOUNCE_COUNTER,F		;Key debounce time checked
	return
	bsf		FLAGS1,DEBOUNCE
	movlw	DEBOUNCE_COUNT
	movwf	DEBOUNCE_COUNTER
	return
;*******************************************************************************
;This routine takes action for the keys pressed
;If SW1(RUN/STOP) Key is pressed, the state toggles between RUN and STOP
;If SW2(FWD/REV) Key is pressed, the state toggles between FORWARD and REVERSE
PROCESS_KEY_PRESSED
	btfss	FLAGS1,KEY_PRESSED			;Is there a key press waiting?
	return
	btfss	FLAGS1,KEY_RS				;Is it RUN/STOP?
	goto	CHECK_FWD_REV
	btfss	FLAGS1,RUN_STOP				;Yes,Was the previous state a Stop?
	goto	STOP_MOTOR_NOW
	call	RUN_MOTOR_AGAIN				;Yes, Then RUN the motor 
	bcf		FLAGS1,KEY_PRESSED			;Clear the Flag
	bcf		FLAGS1,KEY_RS
;	bsf		LED_PORT,RUN_STOP_LED		;Turn on LED to indicate motor running	
	return

STOP_MOTOR_NOW							
	call	STOP_MOTOR					;Was the previous state a RUN?, Then stop the motor
	bcf		FLAGS1,KEY_PRESSED
	bcf		FLAGS1,KEY_RS
;	bcf		LED_PORT,RUN_STOP_LED		;Clear Flags and indicate motor stopped on LED
	return


CHECK_FWD_REV
	btfss	FLAGS1,KEY_FR				;Is the Key pressed = FWD/REV?
	return

;	btg		LED_PORT,FWD_REV_LED		;Yes,
;	bcf		LED_PORT,RUN_STOP_LED	
	call	STOP_MOTOR					;Stop the motor before reversing

	call	BIG_DELAY					;Delay between reversing the direction
	call	BIG_DELAY

	call	RUN_MOTOR_AGAIN				;Run the motor in Reverse direction
	bcf		FLAGS1,KEY_PRESSED			;Clear Flags
	bcf		FLAGS1,KEY_FR
;	bsf		LED_PORT,RUN_STOP_LED	
	return


;*******************************************************************************
;THIS ROUTINE STOPS THE MOTOR BY DRIVING THE PWMS TO 0% DUTY CYCLE. ALSO DISABLE
;SELECT INTERRUPT TO MAINTAIN STOP CONDITION OF MOTOR
;*******************************************************************************
STOP_MOTOR
	movlw	b'00111111'	;Turn off PWM1,3,5 PWMs(active low) at the beginning of the cycle
	movwf	PWM_PORT	;& turn on PWM0,2,4
	bsf		STATUS,RP0	
	bcf		PIE1,TMR1IE
	bcf		PIE1,ADIE
	bcf		STATUS,RP0
	bcf		INTCON,T0IE
	bcf		FLAGS,MOTOR_FREQ_COUNTER
	clrf	TABLE_OFFSET1
	clrf	TABLE_OFFSET2
	clrf	TABLE_OFFSET3

;	bcf		PORT_RELAY,RELAY_BIT
	RETURN
;*******************************************************************************
;THIS ROUTINE STARTS MOTOR FROM PREVIOUS STOP WITH MOTOR PARAMETERS INITIALIZED
;*******************************************************************************
RUN_MOTOR_AGAIN
	call	INIT_MOTOR_PARAMETERS
	bsf		STATUS,RP0
	bsf		PIE1,TMR1IE
	bcf		STATUS,RP0
	bsf		INTCON,T0IE
	RETURN

;*******************************************************************************
;THIS ROUTINE INITIALIZES THE PARAMETERS REQUIRED FOR MOTOR INITIALIZATION.
;*******************************************************************************
INIT_MOTOR_PARAMETERS
#ifdef PSC_MOTOR_CONTROL

	movlw	0X012				;INITIALIZE THE TABLE OFFSET TO 3 REGISTERS
	movwf	TABLE_OFFSET1			;TO FORM 0-120-240 DEGREES

	movlw	0X00
	movwf	TABLE_OFFSET2
	
	movlw	0X08
	movwf	TABLE_OFFSET3
	
	bcf		FLAGS,OFFSET1_FLAG		;OFFSET FLAGS INITIALIZATION
	bsf		FLAGS,OFFSET2_FLAG

	btfsc	FLAGS1,FWD_REV	
	goto	INIT_MOT_REV
	bsf		FLAGS,OFFSET3_FLAG		;Offset3 initialized  
	goto	INIT_MOT_FREQ
INIT_MOT_REV
	bcf		FLAGS,OFFSET3_FLAG
#endif
#ifdef THREE_PHASE_MOTOR_CONTROL
	movlw	0x09			;Initialize the table offset to 3 registers
	movwf	TABLE_OFFSET1		;to form 0-120-240 degrees
	bsf	FLAGS,OFFSET1_FLAG	;Offset flags initialization

	btfsc	FLAGS1,FWD_REV	
	goto	INIT_MOT_REV

	movlw	0x03
	movwf	TABLE_OFFSET2
	bcf	FLAGS,OFFSET2_FLAG

	movlw	0x0F
	movwf	TABLE_OFFSET3
	bcf	FLAGS,OFFSET3_FLAG
	goto	INIT_MOT_FREQ

INIT_MOT_REV
	movlw	0x0F
	movwf	TABLE_OFFSET2
	bcf	FLAGS,OFFSET2_FLAG

	movlw	0x03
	movwf	TABLE_OFFSET3
	bcf	FLAGS,OFFSET3_FLAG

#endif

INIT_MOT_FREQ
	movlw	0XB1
	movwf	TMR0
	bsf		FLAGS,MOTOR_FREQ_COUNTER
	RETURN

;*******************************************************************************
;ROUTINE FOR 8*8 BIT MULTIPLICAION
;*******************************************************************************
MUL_8X8   
	clrf    RESULT_MSB
	clrf    RESULT_LSB
	movf    NEW_FREQ,W	        	;MOVE THE MULTIPLICAND TO W REG.
	bcf     STATUS,C    			;CLEAR THE CARRY BIT IN THE STATUS REG.
	MULT    0
	MULT    1
	MULT    2
	MULT    3
	MULT    4
	MULT    5
	MULT    6
	MULT    7
	RETLW   0

;*******************************************************************************
;UPON INITIALIZATION THE SINE TABLE CONTENTS ARE COPIED TO THE RAM FROM 
;PROGRAM MEMORY 
;*******************************************************************************
COPY_TABLE_TO_RAM
	BANKSEL	SINE_TABLE_RAM
	BANKISEL	SINE_TABLE_RAM
	movlw	LOW SINE_TABLE_RAM
	movwf	FSR
	movlw	0X13
	movwf	TEMP_LOC
	clrf	TEMP_LOC_1
COPY_AGAIN
	movlw	HIGH	SINE_TABLE
	movwf	PCLATH	
	movf	TEMP_LOC_1,W
	call	SINE_TABLE
	movwf	INDF
	INCF	TEMP_LOC_1,F
	INCF	FSR,F
	DECFSZ	TEMP_LOC,F
	goto	COPY_AGAIN

	movlw	LOW	SINE_TABLE_RAM		;FSR POINTS TO THE STARTING OF THE TABLE
	movwf	FSR
	RETURN		

;*******************************************************************************
;GENERAL PURPOSE DELAY ROUTINE - PRESENT DELAY TIME ~38msec
;*******************************************************************************
DELAY
	movlw	DELAY_COUNT1
	movwf	TEMP_LOC
DEC_TEMP_LOC
	movlw	DELAY_COUNT2
	movwf	TEMP_LOC_1
DEC_TEMP_LOC_1
	DECFSZ	TEMP_LOC_1,F
	goto	DEC_TEMP_LOC_1
	DECFSZ	TEMP_LOC,F
	goto	DEC_TEMP_LOC
	RETURN	

B_DELAY
	call	DELAY
	call	DELAY
	call	DELAY
	call	DELAY
	call	DELAY
	call	DELAY
	call	DELAY
	call	DELAY
	call	DELAY
	call	DELAY
	call	DELAY
	return

BIG_DELAY
	call	B_DELAY
	call	B_DELAY
	call	B_DELAY
	call	B_DELAY
	return

;*******************************************************************************
;EQUATION USED FOR CALCULATION OF SINE TABLE ENTRIES = (SIN(ANGLE)+1)*FF/2
;Sine table has value corresponding to every 10 electrical degrees
;*******************************************************************************
TABLE	CODE	0X0005
SINE_TABLE
	addwf	PCL,F

	RETLW	.2	
	RETLW	.4	
	RETLW	.8		
	RETLW	.16		
	RETLW	.24		
	RETLW	.34		
	RETLW	.50		
	RETLW	.64		
	RETLW	.80		
	RETLW	.96		
	RETLW	.112	
	RETLW	.128	
	RETLW	.144	
	RETLW	.156	
	RETLW	.168	
	RETLW	.178	
	RETLW	.184	
	RETLW	.188	
	RETLW	.190	





	END