#include 	"c:\miniide\hcs12.inc"
wait20us	macro	
		movb	#$90,TSCR1	; wait for 20 ms
		movb	#0,TSCR2	;  	“
		bset	TIOS,$01	; 	“
		ldd	TCNT		; 	“
		addd	#470		; 	“
		std	TC0		; 	“
		brclr	TFLG1,C0F,*	; 	“
		endm
openATD0	movb	#$E0,ATD0CTL2
		wait20us		; wait for 20 us
		movb	#$22,ATD0CTL3
		movb	#$05,ATD0CTL4
		rts