;****************************************************************
;cntr_demo				Counter Demonstration					
;This program demos Timer 0 as counter, using ping-pong hardware 
;TJW 15.4.05				Tested 15.4.05
;****************************************************************
;Clock freq 800kHz approx (RC osc.)
;Port A 4  right paddle (ip) Counter input.
;	2  "out of play" led (op)
;Port B 7-0  "play" leds (all op)
;Interrupts not used
;Config Word: RC oscillator, WDT off, PU timer on, code protect off
;
	#include p16f84A.inc
;
	org 	00
; Initialise
	bsf	status,rp0 	;select memory bank 1
	movlw	B'00011000'
	movwf	trisa		;port A according to above pattern 
	movlw	00
	movwf	trisb		;all port B bits outout
	movlw 	B'00101000'	;set up TMR0 for external input, +ve edge, 
							;no prescale
	movwf 	TMR0		;as we are in Bank 1, this addresses OPTION
	bcf	status,rp0 	;select bank 0
;
	movlw	04		;switch on "out of play" led to show power is on
	movwf	porta	
loop 	movf	TMR0,0		;Continuously display Timer 0 on Port B
	movwf	portb
	goto 	loop
	end