; *******************************************************************
; Curso Pic Leccion 3 - "Rotate"
;
; Continuando con la leccion 2 ahora haremos que se desplace el led encendido

#include <p16F877A.inc>
	__config _WDT_OFF & _PWRTE_ON & _LVP_ON & _CP_OFF & _XT_OSC

	cblock 0x20
Delay1		; Assign an address to label Delay1
Delay2
Display		; define a variable to hold the diplay
	endc
	
	org 0
Start
	bsf	STATUS,RP0	; select Register Page 1
	clrf	TRISC		; make IO PortC all output
	bcf	STATUS,RP0	; back to Register Page 0
	movlw	0x08
	movwf	Display
MainLoop
	movf	Display,w	; Copy the display to the LEDs
	movwf	PORTC
OndelayLoop
	decfsz	Delay1,f	; Waste time.  
	goto	OndelayLoop	; The Inner loop takes 3 instructions per loop * 256 loopss = 768 instructions
	decfsz	Delay2,f	; The outer loop takes and additional 3 instructions per lap * 256 loops
	goto	OndelayLoop	; (768+3) * 256 = 197376 instructions / 1M instructions per second = 0.197 sec.
				; call it a two-tenths of a second.
	
	bcf	STATUS,C	; ensure the carry bit is clear
	rrf	Display,f
	btfsc	STATUS,C	; Did the bit rotate into the carry?
	bsf	Display,3	; yes, put it into bit 3.
	goto	MainLoop
	end
; Como se habrá observado, solo se utilizaron 4 salidas del puerto C
; Modifique el programa para que se puedan utilizar las 8 salidas del puerto C
; Tip, revise el valor de la variable Display.