Ergänzungen zu VHDL - Technische Informatik - page 491

• Rotations- und Verschiebeoperatoren:
function "sll" (a: tUnsigned; n:natural) return tUnsigned;
function "sll" (a: tSigned; n:natural) return tSigned;
function "srl" (a: tUnsigned; n:natural) return tUnsigned;
function "srl" (a: tSigned; n:natural) return tSigned;
function "rol" (a: tUnsigned; n:natural) return tUnsigned;
function "rol" (a: tSigned; n:natural) return tSigned;
function "ror" (a: tUnsigned; n:natural) return tUnsigned;
function "ror" (a: tSigned; n:natural) return tSigned;
function "sla" (a: tUnsigned; n:natural) return tUnsigned;
function "sla" (a: tSigned; n:natural) return tSigned;
function "sra" (a: tUnsigned; n:natural) return tUnsigned;
function "sra" (a: tSigned; n:natural) return tSigned;
• Vergleichsoperatoren:
function "=" (a, b: tUnsigned) return boolean;
function "=" (a, b: tSigned) return boolean;
function "/=" (a, b: tUnsigned) return boolean;
function "/=" (a, b: tSigned) return boolean;
function ">" (a, b: tUnsigned) return boolean;
function ">" (a, b: tSigned) return boolean;
function "<" (a, b: tUnsigned) return boolean;
function "<" (a, b: tSigned) return boolean;
function ">=" (a, b: tUnsigned) return boolean;
function ">=" (a, b: tSigned) return boolean;
function "<=" (a, b: tUnsigned) return boolean;
function "<=" (a, b: tSigned) return boolean;
Die nachfolgenden Funktionen und Prozeduren dienen ausschließlich zur Si-
mulation, im Simulations-Package mit und im Synthese-Package ohne Berück-
sichtigung des Pseudo-Wertes »ungültig«:
• Test auf Gültigkeit:
function is_x (a: tUnsigned) return boolean;
function is_x (a: tSigned) return boolean;
• Umwandlung in eine Textdarstellung:
function str(x: tUnsigned; fmt:character:= 'b' ) return string;
function str(x: tSigned; fmt:character:= 'b' ) return string;
• Abräumen von einem Zeichenbandobjekt:
procedure get(pstr: inout tPString; w: out tUnsigned);
procedure get(pstr: inout tPString; w: out tSigned);
• Aufforderung zu einer Tastatureingabe:
procedure read(promt:string; w: out tUnsigned);
procedure read(promt:string; w: out tSigned);