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Help with commenting on my code

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Darkstar3000

New Member
So I have this question

Write an assembly language program for PIC 16F684 to switch ON LEDs to count in binary from 0 to 7. Allow a delay of about 1second between the change.Write the program, verify its operation by executing it

I wrote the program but I'm not sure if it does the job correctly since I'm not really comfortable with assembly language so can anyone take a look at it and tell me if it's doing what the question specifies and if my comments are correct. I can't test it out as I'm currently on vacation so I just need a verification of my work.

I'm using MPLAB V8.84

Thanks in advance.
Code: 
; WRITTEN BY            
; DATE                  28/04/12
; FILE SAVED AS         BinaryCounter.asm
; DEVICE                PIC16F684
; FUNCTION				PROGRAM COUNTS FROM 0 TO 7 IN BINARY
; -----------------------   EQUATES    ------------------------------------
PORTA   EQU     05h    ;LABELS THE PORTA REGISTER AS "PORTA"
;DELAY COUNTERS 
COUNT1 EQU 20h;
COUNT2 EQU 21h

;------------------------ CONSTANTS -----------------------------------------
;IDENTIFIES CONSTANTS FOR REQUIRED LEDS
;I/O for LEDS
#define TRIS_D0_D1	B'00001111'	; TRISIO SETTING FOR D0 AND D1
#define TRIS_D2_D3	B'00101011'	; TRISIO SETTING FOR D2 AND D3

; the LEDS
#define D0	B'00010000'		; D0 LED
#define D1	B'00100000'		; D1 LED
#define D2	B'00010000'		; D2 LED
#define D3	B'00000100'		; D3 LED

; ----------------------- MAIN PROGRAM ------------------------------------
START   ORG     0X00    ;'ORG' SPECIFIES THE MEMORY LOCATION OF THE PROGRAM

; LED 0 ON
LOOP0
        MOVLW   TRIS_D0_D1;		;PUT 00001111 INTO W
        TRIS    PORTA   		;
        CLRF    PORTA			;CLEAR THE CONTENTS OF PORTA
        MOVLW   D0      		;PUT 00010000 INTO W
        MOVWF   PORTA   		;MOVE W ONTO PORTA 
		
		;Delay:
		decfsz    COUNT1,1       ;DECREASE THE VALUE OF COUNT1 BY 1
								 ;AND SKIP NEXT LINE IF RESULT IS ZERO
        goto      LOOP0          ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								 ;GO TO LOOP0	
        decfsz    COUNT2,1       ;DECRESE THE VALUE OF COUNT2 BY 1
								 ;AND SKIP NEXT LINE IF RESULT IT ZERO	
        goto      LOOP0          ;IF COUNT2 IS ZERO, CARRY ON OTHERWISE
								 ;GO TO LOOP0


; LED 1 ON
LOOP1
        CLRF    PORTA;			;CLEAR THE CONTENTS OF PORTA
		MOVLW   TRIS_D0_D1;     ;PUT 00001111 INTO W	
        TRIS    PORTA   		; 
        CLRF    PORTA   		;CLEAR THE CONTENTS OF PORTA
        MOVLW   D1   			;PUT 00100000 INTO W
        MOVWF   PORTA  			;MOVE W ONTO PORTA
		
		;Delay:
		decfsz    COUNT1,1      ;DECREASE THE VALUE OF COUNT1 BY 1
								;AND SKIP THE NEXT LINE IF RESULT IS ZERO
        goto      LOOP1         ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP1
        decfsz    COUNT2,1      ;DECREASE THE VALUE OF COUNT2 BY 1 
        goto      LOOP1         ;GO TO LOOP1

; LED 1 & 2 ON
LOOP2
        ;1
        CLRF    PORTA;		    ;CLEAR THE CONTENTS OF PORTA 
		MOVLW   TRIS_D0_D1		;PUT 00001111 INTO W
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR THE CONTENTS OF PORTA
        MOVLW   D1   			;PUT 00100000 INTO W	
        MOVWF   PORTA  			;MOVE W ONTO PORTA 
		
		;2
		CLRF    PORTA		    ;CLEAR THE CONTENTS OF PORTA
		MOVLW   TRIS_D2_D3		;PUT 00101011 INTO W
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR THE CONTENTS OF PORTA
        MOVLW   D2   			;PUT 00010000 INTO W
        MOVWF   PORTA  			;MOVE W ONTO PORTA 
		
		;Delay:
		decfsz    COUNT1,1		;DECREASE THE VALUE OF COUNT1 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO
        goto      LOOP2         ;IF COUNT IS ZERO,CARRY ON OTHERWISE 
								;GO TO LOOP 2 
        decfsz    COUNT2,1      ;DECRESE THE VALUE OF COUNT2 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO 	
        goto      LOOP2         ;IF COUNT2 IS ZERO, CARRY ON OTHERWISE 
								;GO TO LOOP2
; LED 3 ON
LOOP3

        CLRF    PORTA		    ;CLEAR THE CONTENTS OF PORTA
		MOVLW   TRIS_D2_D3;		;PUT 00101011 INTO W
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR THE CONTENTS OF PORTA
        MOVLW   D3   			;PUT 00000100 INTO W 
        MOVWF   PORTA  			;MOVE W ONTO PORTA
		
		;Delay:
		decfsz    COUNT1,1       ;DECREASE THE VALUE OF COUNT1 BY 1
								 ;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO	
        goto      LOOP3          ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								 ;GO TO LOOP3
        decfsz    COUNT2,1       ;DECREASE THE VALUE OF COUNT2 BY 1 
								 ;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO
        goto      LOOP3        	 ;IF COUNT2 IS ZERO, CARRY ON OTHERWISE
								 ;GO TO LOOP3 
		
; LED 3 & 1 ON
LOOP4

        CLRF    PORTA		    ;CLEAR THE CONTENTS OF PORTA
		MOVLW   TRIS_D2_D3;		;PUT 00101011 INTO W		
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR THE CONTENTS OF PORTA
        MOVLW   D3   			;PUT 00000100 INTO W
        MOVWF   PORTA 			;MOVE W TO PORTA 
		
		CLRF    PORTA				;CLEAR THE CONTENTS OF PORTA
		MOVLW   TRIS_D0_D1		;PUT 00001111 INTO W
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR THE CONTENTS OF PORTA
        MOVLW   D1  			;PUT 00010000 INTO W
        MOVWF   PORTA 			;MOVE W ONTO PORTA
		
		;Delay:
		decfsz    COUNT1,1      ;DECREASE THE VALUE OF COUNT1 BY 1 
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO	
        goto      LOOP4         ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP4
        decfsz    COUNT2,1      ;DECREASE THE VALUE OF COUNT2 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO
        goto      LOOP4         ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP4

; LED 3 & 2 ON		
LOOP5
        CLRF    PORTA			;CLEAR THE CONTENTS OF PORTA				
		MOVLW   TRIS_D2_D3		;PUT 00101011 INTO W	
        TRIS    PORTA   		;	
        CLRF    PORTA   		;CLEAR THE CONTENTS OF PORTA
        MOVLW   D3   			;PUT 00000100 INTO W
        MOVWF   PORTA 			;MOVE W TO PORTA
		
		CLRF    PORTA			;CLEAR THE CONTENTS OF PORTA
		MOVLW   TRIS_D2_D3;		;PUT 00101011 INTO W 
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR THE CONTENTS OF PORTA
        MOVLW   D2  			;00010000
        MOVWF   PORTA 			;MOVE W TO PORTA 
		
		;Delay:
		decfsz    COUNT1,1      ;DECREASE THE VALUE OF COUNT1 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO
        goto      LOOP5         ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP5 
        decfsz    COUNT2,1      ;DECREASE THE VALUE OF COUNT2 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO 	
        goto      LOOP5        	;IF COUNT2 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP5

; LED 3 & 2 & 1
LOOP6
     
	    CLRF    PORTA			;CLEAR THE CONTENTS OF PORTA
		MOVLW   TRIS_D2_D3		;PUT 00101011 INTO W
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR THE CONTENTS OF PORTA
        MOVLW   D3   			;PUT 00000100 INTO W
        MOVWF   PORTA 			;MOVE W TO PORTA
		
		CLRF    PORTA			;CLEAR THE CONTENTS OF PORTA
		MOVLW   TRIS_D2_D3		;PUT 00101011 INTO W
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR THE CONTENTS OF PORTA
        MOVLW   D2  			;PUT 00010000 INTO W
        MOVWF   PORTA 			;MOVE W TO PORTA 
		
		CLRF    PORTA			;CLEAR CONTENTS OF PORTA	
		MOVLW   TRIS_D0_D1		;PUT 00001111 INTO W	 
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR CONTENTS OF PORTA
        MOVLW   D1  			;PUT 00010000 INTO W
        MOVWF   PORTA 			;MOVE W TO PORTA 
		
		;Delay:
		decfsz    COUNT1,1      ;DECREASE THE VALUE OF COUNT1 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO 
        goto      LOOP6         ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP6
        decfsz    COUNT2,1      ;DECREASE THE VALUE OF COUNT2 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO 	
        goto      LOOP6         ;IF COUNT2 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP6

		

        END

Here's a link to the asm if the code is messy **broken link removed**
 
Last edited:
You are creating INPUTS:

MOVLW TRIS_D0_D1

PUT 00001111 INTO W


You need much better documentation.
Don't just comment about WHAT the instruction is doing but WHY it is being done
 
Last edited:
colin55 said:
You are creating INPUTS:

MOVLW TRIS_D0_D1

PUT 00001111 INTO W


You need much better documentation.
Don't just comment about WHAT the instruction is doing but WHY it is being done
Click to expand...

Alright, that makes sense but I pieced this program together from samples given to us throughout the weeks so I'm not really sure what everything is doing. That's why my comments lack detail.
 
Here's a revised version with hopefully better comments

Code: 
; WRITTEN BY            
; DATE                  28/04/12
; FILE SAVED AS         BinaryCounter.asm
; DEVICE                PIC16F684
; FUNCTION				PROGRAM COUNTS FROM 0 TO 7 IN A BINARY SEQUENCE USING LEDS 
; -----------------------   EQUATES    ------------------------------------
PORTA   EQU     05h    ;LABELS THE PORTA REGISTER AS "PORTA"
;DELAY COUNTERS TO COUNT DOWN A DELAY
COUNT1 EQU 20h;
COUNT2 EQU 21h

;------------------------ CONSTANTS -----------------------------------------
;IDENTIFIES CONSTANTS FOR REQUIRED LEDS
;I/O for LEDS
#define TRIS_D0_D1	B'00001111'	; TRISIO SETTING FOR D0 AND D1
#define TRIS_D2_D3	B'00101011'	; TRISIO SETTING FOR D2 AND D3

; the LEDS
#define D0	B'00010000'		; D0 LED
#define D1	B'00100000'		; D1 LED
#define D2	B'00010000'		; D2 LED


; ----------------------- START OF PROGRAM ------------------------------------
START   ORG     0X00    ;'ORG' SPECIFIES THE MEMORY LOCATION OF THE PROGRAM

; LED 0 ON
LOOP0
        MOVLW   TRIS_D0_D1;		;MOVE PREDEFINED VALUE TO TRISA TO SWITCH ON LED0
        TRIS    PORTA   		;
        CLRF    PORTA			;CLEAR ALL OUTPUTS 
        MOVLW   D0      		;ASSIGN THE VALUE OF D0 TO W 
        MOVWF   PORTA   		;MOVE PREDEFINED VALUE TO PORTA TO SWITCH ON LED0
		
		;Delay:
		decfsz    COUNT1,1       ;DECREASE THE VALUE OF COUNT1 BY 1
								 ;AND SKIP NEXT LINE IF RESULT IS ZERO
        goto      LOOP0          ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								 ;GO TO LOOP0	
        decfsz    COUNT2,1       ;DECRESE THE VALUE OF COUNT2 BY 1
								 ;AND SKIP NEXT LINE IF RESULT IT ZERO	
        goto      LOOP0          ;IF COUNT2 IS ZERO, CARRY ON OTHERWISE
								 ;GO TO LOOP0


; LED 1 ON
LOOP1
        CLRF    PORTA;			;CLEAR ALL OUTPUTS
		MOVLW   TRIS_D0_D1;     ;MOVE PREDEFINED VALUE TO TRISA TO SWITCH ON LED1	
        TRIS    PORTA   		; 
        CLRF    PORTA   		;CLEAR ALL OUTPUTS 
        MOVLW   D1   			;ASSIGN THE VALUE OF D1 TO W 
        MOVWF   PORTA  			;MOVE PREDEFINE VALUE TO PORTA TO SWITCH ON LED1
		
		;Delay:
		decfsz    COUNT1,1      ;DECREASE THE VALUE OF COUNT1 BY 1
								;AND SKIP THE NEXT LINE IF RESULT IS ZERO
        goto      LOOP1         ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP1
        decfsz    COUNT2,1      ;DECREASE THE VALUE OF COUNT2 BY 1 
        goto      LOOP1         ;GO TO LOOP1

; LED 0 & 1 ON
LOOP2
        ;0
        CLRF    PORTA;		    ;CLEAR ALL OUTPUTS 
		MOVLW   TRIS_D0_D1		;MOVE PREDEFINED VALUE TO TRISA TO SWITCH ON LED0
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR ALL OUTPUTS
        MOVLW   D0   			;ASSSIGN THE VALUE OF D0 TO W 	
        MOVWF   PORTA  			;MOVE PREDEFINE VALUE TO PORTA TO SWITCH ON LED0
		
		;1
		CLRF    PORTA		    ;CLEAR ALL OUTPUTS
		MOVLW   TRIS_D0_D1		;MOVE PREDEFINED VALUE TO TRISA TO SWITCH ON LED1
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR ALL OUTPUTS
        MOVLW   D1   			;ASSIGN THE VALUE OF D0 TO W
        MOVWF   PORTA  			;MOVE PREDEFINED VALUE TO PORTA TO SWITCH ON LED1
		
		;Delay:
		decfsz    COUNT1,1		;DECREASE THE VALUE OF COUNT1 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO
        goto      LOOP2         ;IF COUNT IS ZERO,CARRY ON OTHERWISE 
								;GO TO LOOP 2 
        decfsz    COUNT2,1      ;DECRESE THE VALUE OF COUNT2 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO 	
        goto      LOOP2         ;IF COUNT2 IS ZERO, CARRY ON OTHERWISE 
								;GO TO LOOP2
; LED 2 ON
LOOP3

        CLRF    PORTA		    ;CLEAR ALL OUTPUTS
		MOVLW   TRIS_D2_D3;		;MOVE PREDEFINED VALUE TO TRISA TO SWITCH ON LED2
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR ALL OUTPUTS
        MOVLW   D2   			;ASSIGN THE VALUE OF D2 TO W 
        MOVWF   PORTA  			;MOVE PREDEFINED VALUE TO PORTA TO SWITH ON LED2
		
		;Delay:
		decfsz    COUNT1,1       ;DECREASE THE VALUE OF COUNT1 BY 1
								 ;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO	
        goto      LOOP3          ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								 ;GO TO LOOP3
        decfsz    COUNT2,1       ;DECREASE THE VALUE OF COUNT2 BY 1 
								 ;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO
        goto      LOOP3        	 ;IF COUNT2 IS ZERO, CARRY ON OTHERWISE
								 ;GO TO LOOP3 
		
; LED 0 & 2 ON
LOOP4
		CLRF    PORTA			;CLEAR ALL OUTPUTS
		MOVLW   TRIS_D0_D1		;MOVE PREDEFINED VALUE TO TRISA TO SWITCH ON LED0
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR ALL OUTPUTS
        MOVLW   D0  			;ASSSIGN THE VALUE OF D0 TO W 
        MOVWF   PORTA 			;MOVE PREDEFINED VALUE TO PORTA TO SWITCH ON LED0		



        CLRF    PORTA		    ;CLEAR ALL OUTPUTS
		MOVLW   TRIS_D2_D3;		;MOVE PREDEFINED VALUE TO TRISA TO SWITCH ON LED2		
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR ALL OUTPUTS
        MOVLW   D2   			;ASSIGN THE VALUE OF D2 TO W 
        MOVWF   PORTA 			;MOVE PREDEFINED VALUE TO PORTA TO SWITCH ON LED2 
		
		
		
		;Delay:
		decfsz    COUNT1,1      ;DECREASE THE VALUE OF COUNT1 BY 1 
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO	
        goto      LOOP4         ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP4
        decfsz    COUNT2,1      ;DECREASE THE VALUE OF COUNT2 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO
        goto      LOOP4         ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP4

; LED 1 & 2 ON		
LOOP5
        CLRF    PORTA			;CLEAR ALL OUTPUTS				
		MOVLW   TRIS_D0_D1		;MOVE PREDEFINED VALUE TO TRISA TO SWITCH ON LED1	
        TRIS    PORTA   		;	
        CLRF    PORTA   		;CLEAR ALL OUTPUTS
        MOVLW   D1  			;ASSIGN THE VALUE OF D1 TO W 
        MOVWF   PORTA 			;MOVE PREDEFINED VALUE TO PORTA TO SWITCH ON LED1
		
		CLRF    PORTA			;CLEAR ALL OUTPUTS
		MOVLW   TRIS_D2_D3;		;MOVE PREDEFINED VALUE TO TRISA TO SWITCH ON LED2
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR ALL OUTPUTS
        MOVLW   D2  			;ASSIGN THE VALUE OF D2 TO W 
        MOVWF   PORTA 			;MOVE PREDEFINED VALUE TO PORTA TO SWITCH ON LED2
		
		;Delay:
		decfsz    COUNT1,1      ;DECREASE THE VALUE OF COUNT1 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO
        goto      LOOP5         ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP5 
        decfsz    COUNT2,1      ;DECREASE THE VALUE OF COUNT2 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO 	
        goto      LOOP5        	;IF COUNT2 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP5

; LED 0 & 1 & 2 ON
LOOP6
     
	    CLRF    PORTA			;CLEAR ALL OUTPUTS
		MOVLW   TRIS_D0_D1		;MOVE PREDEFINE VALUE TO TRISA TO SWITCH ON LED0
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR ALL OUTPUTS
        MOVLW   D0   			;ASSING THE VALUE OF D0 TO W
        MOVWF   PORTA 			;MOVE PREDEFINED VALUE TO PORTA TO SWITCH ON LED0
		
		CLRF    PORTA			;CLEAR ALL OUTPUTS 
		MOVLW   TRIS_D0_D1		;MOVE PREDEFINED VALUE TO TRISA TO SWITCH ON LED1
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR ALL OUTPUTS
        MOVLW   D1  			;ASSIGN THE VALUE OF D1 TO W 
        MOVWF   PORTA 			;MOVE PREDEFINED VALUE TO PORTA TO SWITCH ON LED1 
		
		CLRF    PORTA			;CLEAR ALL OUTPUTS
		MOVLW   TRIS_D2_D3		;MOVE PREDEFINED VALUE TO TRISA TO SWITCH ON LED2	 
        TRIS    PORTA   		;
        CLRF    PORTA   		;CLEAR ALL OUTPUTS
        MOVLW   D2  			;ASSING THE VALUE OF D2 TO W
        MOVWF   PORTA 			;MOVE PREDEFINED VALUE TO PORTA TO SWITCH ON LED2
		
		;Delay:
		decfsz    COUNT1,1      ;DECREASE THE VALUE OF COUNT1 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO 
        goto      LOOP6         ;IF COUNT1 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP6
        decfsz    COUNT2,1      ;DECREASE THE VALUE OF COUNT2 BY 1
								;AND SKIP THE NEXT LINE IF THE RESULT IS ZERO 	
        goto      LOOP6         ;IF COUNT2 IS ZERO, CARRY ON OTHERWISE
								;GO TO LOOP6

		

        END


and the link to the asm **broken link removed**
 
Homework?

I hope this helps you. It is commented and somewhat simpler than your approach.;)

Code: 
;**********************************************************************
;                                                                     *
;    Files Required: P16F84.INC                                      *
;                                                                     *

	list		p=16f84		; list directive to define processor
	#include	"P16F84.inc"		; processor specific variable definitions

	
	__CONFIG    _PWRTE_ON  & _WDT_OFF &_HS_OSC  & _CP_OFF ;HS oscillator active.

	

	;****************GPR declarations****************		; note Bank0 last 16bytes,0x70 to 0x7f, visible in all banks as local last 16.
	COUNT0		EQU  	0x20 	; 
	COUNT1		EQU	0x21
	Number		EQU	0x22 ; temp use.
	
	
	Org	0x000				; processor reset vector
 	goto	Main			; go to beginning of program
 	
	
Main;
	;@ an osc clock of 4Mhz, the instruction clock = 1Mhz.
	; 1 sec delay loop requires 1 million instructions
	; A 15 instruction loop run 256 * 256 times will yield approx 1 sec delay.
	;**********************;
	;**Initialize variables**;
	clrf COUNT0
	clrf COUNT1
	clrf  Number
	
	;Setup PORT I/O********
	banksel TRISA; select PORTs i/o setup (bank1)
	clrf TRISA; make PORTA all outputs
	banksel PORTA; select PORTA (bank0)again
	
	; Start binary count
Bcount; increment 3 LED display driven by PORTA,0,1,2 to count in binary to 7 continously
	movf Number,w; get binary number from GPR into W register
	andlw 7; mask number to limit to 7 maximum, 7 = binary 00000111, result in w register
	movwf PORTA; move binary number into PORTA: PORTA,0,1,2 pins will drive the 3 LEDS counting binary to 7.
	incf Number,f; increment binary Number variable GPR by 1
	call Delay0; call a 1 second delay subroutine
	goto Bcount; continuous loop.
	
Delay0; this section consumes 3 inst. * 256 = 768 inst. = .000768 sec , negligible amt.
	incf COUNT0,f
	skpnz
	return
Delay1; 15 cycles *256*256 =  .98304 sec. approx 1 sec.
	incf COUNT1,f; 1 inst cycle
	goto $+1; goto next program line= 2 inst cycles
	goto $+1;"
	goto $+1;"
	goto $+1;"
	goto $+1;"
	nop; 1 inst cycle
	skpnz; 1 inst cycle
	goto Delay0; 2 inst cycles
	goto Delay1 ; 2 inst cycles
	
	END; eof
 
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