软件编程设计-外文翻译(编辑修改稿)

软件编程设计-外文翻译(编辑修改稿)内容摘要：

e structure, behavior which describes numerical system, function with addition to implying many languages sentence which have a hardware characteristic, VHDL languages forms and description style and sentence construction are very similar at general calculator deluxe procedure structure characteristics is an engineering design, or call that the design entity(can be a ponent, an electric circuit mold piece or a system) is divided into exterior(or call but part, and port) with inner part(or call to can39。 t see part), since involve internal function and calculate way of entity to plete part to 1 designed entity to define exterior interface after, once it internal development pletion after, other designs can directly adjust to use this kind of will design entity to be divided into a little bit basic VHDL system that is a VHDL system inside the concept of outside part design design of a little bit basic and other hardware describe the language pare and the VHDL has a following characteristics: The function is strong and the design be VHDL has the function strong language structure, can describe a plicated logic control with the simple and direct and explicit source has a multilayer design description function, in multiple layers thin turn, finally directly born electric circuit class VHDL supports synchronous electric circuit, difference39。 s tread electric circuit with random the design of electric circuit, this be the other hardware description although the language can39。 t pare VHDL still supports various design method, since support from the bottom upward design, support again from the design of crest declivity。 Since the support mold piece turns a design, support layer39。 s turn a design again. Support extensively and be easy to a the VHDL has already bee IEEE standard the norm of hardware description language, most EDA tools almost support VHDL currently, this is VHDL of further expansion with extensively applied lay the design process of the hardware electric circuit, the main design document is the source code which writes with the VHDL, the VHDL easily reads with the structure turn, so be easy to a modification design. The strong system hardware describes VHDL has a multilayer design description function, since can describe system class electric circuit, can describe door class electric circuit description since can adopt a behavior description, deposit a machine to deliver description or structure description, can also adopt the hybrid description of threes , VHDL support is inertial to delay and deliver to delay, can also accurately build up hardware electric circuit support prepare definite of with from definition of data type, bring hardware description a bigger freedom degree, make design the personnel can expediently establish the system model of high time. The independence is at the design of spare part, have nothing to do with the 39。 t need to consider a choice pletion the spare part of design first while designing a personnel to carry。