#include "c:\miniide\hcs12.inc"
PM7		equ	BIT7
PM6		equ	BIT6
prologue	macro	
		bset	PTM,PM7	; pull FS to high
		bclr	PTM,PM6	; pull CS to low
		bclr	PTM,PM7	; pull FS to low
		endm
epilogue	macro
		bset	PTM,PM7	; pull FS to high
		bset	PTM,PM6	; pull CS to high
		endm

		org	$1500
		lds	#$1500	; set up the stack pointer
		bset	DDRM,$C0	; configure the PM6 and PM7 pins for output
		jsr	openspi0	; configure SPI0 properly
forever	prologue		; activate an FS pulse and pull CS to low
		ldaa	#$40		; output 0V from OUT pin
		jsr	putcspi0	;	"
		ldaa	#0		;	"
		jsr	putcspi0	;	"
		epilogue		; pull PM7 and PM6 to high
		ldy	#1		; wait for 1 ms
		jsr	delayby1ms	;	"		
		prologue		; activate an FS pulse and pull CS to low
		ldaa	#$44		; output 1V from OUT pin
		jsr	putcspi0	;	"
		ldaa	#0		;	"
		jsr	putcspi0	;	"
		epilogue		; pull PM7 and PM6 to high
		ldy	#1		; wait for 1 ms
		jsr	delayby1ms	;	"
		prologue		; activate an FS pulse and pull CS to low
		ldaa	#$48		; output 2V from OUT pin
		jsr	putcspi0	;	"
		ldaa	#0		;	"
		jsr	putcspi0	;	"
		epilogue		; pull PM7 and PM6 to high
		ldy	#1		; wait for 1 ms
		jsr	delayby1ms	;	"
		prologue		; activate an FS pulse and pull CS to low
		ldaa	#$44		; output 1V from OUT pin
		jsr	putcspi0	;	"
		ldaa	#0		;	"
		jsr	putcspi0	;	"
		epilogue		; pull PM7 and PM6 to high
		ldy	#1		; wait for 1 ms
		jsr	delayby1ms	;	"
		prologue		; activate an FS pulse and pull CS to low
		ldaa	#$48		; output 2V from OUT pin
		jsr	putcspi0	;	"
		ldaa	#0		;	"
		jsr	putcspi0	;	"
		epilogue		; pull PM7 and PM6 to high
		ldy	#1		; wait for 1 ms
		jsr	delayby1ms	;	"
		prologue		; activate an FS pulse and pull CS to low
		ldaa	#$44		; output 1V from OUT pin
		jsr	putcspi0	;	"
		ldaa	#0		;	"
		jsr	putcspi0	;	"
		epilogue		; pull PM7 and PM6 to high
		ldy	#1		; wait for 1 ms
		jsr	delayby1ms	;	"
		prologue		; activate an FS pulse and pull CS to low
		ldaa	#$48		; output 2V from OUT pin
		jsr	putcspi0	;	"
		ldaa	#0		;	"
		jsr	putcspi0	;	"
		epilogue		; pull PM7 and PM6 to high
		ldy	#1		; wait for 1 ms
		jsr	delayby1ms	;	"
		prologue		; activate an FS pulse and pull CS to low
		ldaa	#$4C		; output 3V from the OUT pin
		jsr	putcspi0	;	"
		ldaa	#0		;	"
		jsr	putcspi0	;	"
		epilogue		; pull PM7 and PM6 to high
		ldy	#1		; wait for 1 ms
		jsr	delayby1ms	;	"
		jmp	forever
openspi0	movb	#0,SPI0BR	; set baud rate to 12 MHz
		movb	#$54,SPI0CR1
		movb	#$02,SPI0CR2
		movb	#0,WOMS	; enable Port S pull-up
		rts
#include 	"c:\miniide\delay.asm"
#include 	"c:\miniide\spi0util.asm"
		end