; *******************************************************************
; Curso Pic Leccion 2 - "Blink"
; La primera leccion mostró como encenter un led
; Ahora veremos como hacerlo parpadear. Ciclos con delay son 
; necesarios para encender y apagar el led, de tal forma que sea visible al ojo humano.

#include <p16F877A.inc>
	__config _WDT_OFF & _PWRTE_ON & _LVP_ON & _CP_OFF & _XT_OSC
	
	cblock 0x20
Delay1			; Define two file registers for the
Delay2			; delay loop
	endc
	
	org 0
Start
	bsf	STATUS,RP0	; select Register Page 1
	bcf	TRISC,0		; make IO Pin B.0 an output
	bcf	STATUS,RP0	; back to Register Page 0
MainLoop
	bsf	PORTC,0		; turn on LED C0
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	PORTC,0		; Turn off LED C0
OffDelayLoop
	decfsz	Delay1,f	; same delay as above
	goto	OffDelayLoop
	decfsz	Delay2,f
	goto	OffDelayLoop
	goto	MainLoop	; Do it again...
	end