;=======================================================================
;Beginning Assembly Language for the SX Microcontroller
;Program 7.3
;=======================================================================
		device	sx28l,oschs3
		device	turbo,stackx,optionx
		IRC_CAL	IRC_SLOW
		reset	start_point
		freq	50000000		; 50 MHz
		org	8
microlow	ds	1
microhi		ds	1
millilow	ds	1
millihi		ds	1
seconds		ds	1
minutes		ds	1
hours		ds	1
		watch	hours,8,udec
		watch	minutes,8,udec
		watch	seconds,8,udec

		org	0
isr		inc	microlow
		snz
		inc	microhi
		cjne	microhi,#$03,iout	; blink every $03e8 periods
		cjne	microlow,#$e8,iout
; 1000 uS already!
		clr	microlow
		clr	microhi
		inc	millilow
		snz
		inc	millihi
		cjne	millihi,#$03,iout
		cjne	millilow,#$e8,iout
; 1000 ms!
		clr	millihi
		clr	millilow
		xor 	rb,#$FF  		; toggle LEDs
		inc	seconds
		cjne	seconds,#60,iout
; seconds roll over
		clr	seconds
		inc	minutes
		cjne	minutes,#60,iout
; minutes roll over
		clr	minutes
		inc	hours
		cjne	hours,#24,iout
; hour roll over
		clr	hours
; could track days if we wanted to
		
; reset time
iout
		mov	w,#-50   		; interrupt every 1uS
		retiw

start_point
		mov   	!rb,#$00    		; all outputs
		clr	microhi
		clr	microlow
		clr	seconds
		clr	hours
		clr	minutes
; set RTCC to internal clock 1:1 ratio
		mov	!option,#$88  		; no prescale
loop
		jmp	loop