ENT|TY的定义语法 ENTITY Identifier IS <Entity Header> <Entity Declarative Part> I BEGIN <Entity Statement Part> I END I ENTITY][ <Entity Simple Name> I WHDL语法的BNF定义ENTITY的定义语法 ENTITY Identifier IS <Entity Header> <Entity Declarative Part> [ BEGIN <Entity Statement Part> ] END [ ENTITY ] [ <Entity Simple Name> ] ; VHDL语法的BNF定义