vhdl语言应用举例，例子程序，简单的程序例子，入门者学习用，vhdl语言应用举例，例子程序，简单的程序例子，入门者学习用-vhdl language application example, example program, a simple program example, beginners learn to use, vhdl language application example, example program, a simple program example, beginners learn to use