;=======================================================================
;Assembly Language Tutorial for the SX Microcontroller
;Program 5.5
;=======================================================================
		device	sx28l,oschs3
		device	turbo,stackx,optionx
		IRC_CAL	IRC_SLOW
		reset	start_point
		freq	50000000   	; 50 MHz
		org	8
second		ds	2		; counter for 1 second tone
delay		ds	1
delay1		ds	1
tone		ds	1   		; tone constant
		org	0
start_point	mov     !rb,#$7F	; make speaker output
; wait for input button
bwait		jnb	rb.0,bp0
		jnb	rb.1,bp1
		jnb	rb.2,bp2
		jb	rb.3,bwait
; tone 3
		mov 	tone,#48
		mov	second,#$01
		mov	second+1,#$01

bp		call	beep
		jmp	bwait

bp2		mov	tone,#24
		mov	second,#$FD		
		mov	second+1,#$01
		jmp	bp

bp1		mov	tone,#12
		mov	second,#$FA
		mov	second+1,#$03
		jmp	bp

bp0		mov	tone,#6
		mov	second,#$F4
		mov	second+1,#$07
		jmp 	bp

; subroutine
beep		
loop		not	rb	    	; toggle bits
		mov	delay1,tone
oloop		clr	delay
wloop		djnz	delay,wloop
		djnz	delay1,oloop
		djnz	second,loop
		djnz	second+1,loop
		ret			; go back to wherever