module voltimetro
title 'voltimetro digital';
volt device 'p22v10';

"	Entradas
	CLK, RST		pin	1,2;
	D0, D1, D2, D3	pin	3,4,5,6;
	D4, D5, D6, D7	pin 	7,8,9,10;
	nINTR		pin 	11;

"	Salidas
	Y0, Y1, Y2, Y3	pin 	22, 21, 20, 19;
	OE, nWR, nRD	pin 	23, 17, 16;
	SEL_D, SEL_U	pin 	15, 14;

"	Definiciones
	D_DEC	=	[D3,D2,D1,D0];
	D_UNI	=	[D7,D6,D5,D4];
	D_OUT	=	[Y3,Y2,Y1,Y0];
	ESTADO 	=	[nWR, OE];
	INI	=	[0,0];
	CONV	=	[1,0];
	FIN	=	[1,1];
	XXX	=	[0,1];
state_diagram	ESTADO
	state	INI:
		gotoCONV;
	state	CONV:
		if (nINTR==0) then FIN
		else CONV;
	state	FIN:
		goto	INI;
	state 	XXX:
		goto	INI;

equations
	nRD = ĦOE;
	SEL:=ĦSEL_D;
	SEL_U:=SEL_D;
when	(SEL_D==1) then
	D_OUT=D_DEC;
else	D_OUT=D_UNI;
	
	nWR.CLK=CLK;	OE.CLK=CLK;
	sel_u.CLK=CLK;	SEL_D.CLK=CLK;
	nWR.RE=RST;	OE.re=RST;
	SEL_U.re=RST;	SEL_D.re=RST;

end voltimetro;