在VHDL结构体中用于描述逻辑功能和电路结构的语句分为顺序语句和并行语句两部分，顺序语句的执行方式十分类似于普通软件语言的程序执行方式，都是按照语句的前后排列方式顺序执行的。-VHDL structure in the body used to describe the logic function and circuit structure of the order of statements and expressions are divided into two parts in parallel statement, modalities for the implementation of the order of statement is very similar to ordinary language software program implementation, are in accordance with the statements before and after the arrangement of the order implementation.