b.asm

Up down counter for microchip ASM code tested

	LIST	P=16F877
	#INCLUDE "P16F877.INC"
;--------------------------------
	ORG		0X00
	GOTO	START
;--------------------------------

START:	
	BSF		STATUS,	RP0
	CLRF	TRISB
	BSF		TRISC,	0
	BSF		TRISC,	1
	CLRF	STATUS
	CLRF	PORTB
	CLRF	PORTC
TEST:
	BTFSS	PORTC,	1 
	GOTO	$ + 2
	GOTO	DOWN
	BTFSS	PORTC,	0
	GOTO	$ - 4
	GOTO	UP
	GOTO	TEST
UP:
	BTFSS	PORTC,	0
	GOTO	$ - 1
	INCF	PORTB,	F
	BTFSC	PORTC,	0
	GOTO	$ - 1
	GOTO	TEST
DOWN:
	BTFSS	PORTC,	1
	GOTO	$ - 1
	DECF	PORTB,	F
	BTFSC	PORTC,	1
	GOTO	$ - 1
	GOTO	TEST
	END