;------------------------------------------------------------------------------
;	transmit.asm
;	Transmission de données sur le port parallèle en mode ECP
;------------------------------------------------------------------------------
hpcr		equ	$ffffc4		;Host Port Control Register Address
hddr		equ	$ffffc8		;Host Data Direction Register address
hdr		equ	$ffffc9		;Host Data Register address
HOSTCLK		EQU	8		;The next 6 equates are used for
PERIPHCLK		EQU	9		;;addressing the handshaking lines in
PERIPHACK		EQU	10		;;Host Data Register
nACKREVERSE		EQU	11
HOSTACK		EQU	12
nREVERSEREQUEST	EQU	13

data		EQU	7

;	org	X:0
;tab	ds	20000		; declaration d1 tableau de 20000 valeurs
cpt	ds	1

	org	P:0
	jmp	begin
	org	p:$100

begin
	jsr	init_ecp
;	move	cpt,R0
	clr	B
boucle
	jsr	line_in
	jsr	read
	move	a0,b0
	jsr	line_out
	inc	b
	inc	b
	inc   b
	move	b0,a0
;	add	#10,a
	jsr	write
	jmp	boucle
;	jmp	fin

;----------------------------------------------------------
; Routine d'initialisation du mode ECP
;----------------------------------------------------------
init_ecp
	bset	#0,x:hpcr
	bclr	#HOSTCLK,x:hddr
	bset	#PERIPHCLK,x:hddr
	bset	#PERIPHCLK,x:hdr
	bset	#PERIPHACK,x:hddr
	bclr	#PERIPHACK,x:hdr
	bset	#nACKREVERSE,x:hddr
	bset	#nACKREVERSE,x:hdr
	bclr	#HOSTACK,x:hddr
	bclr	#nREVERSEREQUEST,x:hddr
	rts

line_in				;Configures the 8 data lines as inputs
	move	x:hddr,a
	and	#$ff00,a
	move	a,x:hddr
	rts

line_out				;Configures the 8 data lines as outputs
	move	x:hddr,a
	or	#$00ff,a
	move	a,x:hddr
	rts

;---------------------------------------------
; routine d'ecriture sur le port parallele
;---------------------------------------------
write
;	jset	#nREVERSEREQUEST,x:hdr,write_end
;	bclr	#nACKREVERSE,x:hdr

	bsr	data_out			;output the data on data lines.
	bset	#PERIPHACK,x:hdr		;assert PeriphAck 
	bclr	#PERIPHCLK,x:hdr		;reset PeriphClk.	
wr1
;	jset	#nREVERSEREQUEST,x:hdr,time_out_wr
	jclr	#HOSTACK,x:hdr,wr1
	bset	#PERIPHCLK,x:hdr
wr2
;	jset	#nREVERSEREQUEST,x:hdr,time_out_wr
	jset	#HOSTACK,x:hdr,wr2
time_out_wr
	bclr	#PERIPHACK,x:hdr		;reset PeriphAck
;	bset	#nACKREVERSE,x:hdr
write_end
	rts

data_out
	move	a0,x0				;Take the least significant byte from
	move	x:hdr,a0			;;aO and send it,
	insert	#$8000,x0,a			;;without modifying
	move	a0,x:hdr			;;the most significant
	move	x:hddr,a1			;;byte from Host Data Register
	or	#$ff,a
	move	a1,x:hddr
	rts

;----------------------------------------------
; routine de lecture sur le port parallele
;----------------------------------------------
read
;	jclr	#nREVERSEREQUEST,x:hdr,*
	bset	#PERIPHCLK,x:hdr		;assert PeriphAck.

rd1	
;	jclr	#nREVERSEREQUEST,x:hdr,time_out_rd
	jset	#HOSTCLK,x:hdr,rd1
	bset	#PERIPHACK,x:hdr
	
;	jsr	delai	
	
rd2	
;	jclr	#nREVERSEREQUEST,x:hdr,read_end
	jclr	#HOSTCLK,x:hdr,rd2
	bsr	data_in

time_out_rd
	bclr	#PERIPHACK,x:hdr		;reset PeriphAck

read_end
	rts

data_in
	move	x:hdr,a0
	extractu #$8000,a,a
	rts

;delai move	#$ff,B0
;del	nop
;	dec	B
;	bne	del
;	rts

;-------------------------------------------------
fin	jmp	fin
	end