说明：  伪随机码发生器的VHDL实现 随着通信理论的发展，早在20世纪40年代，香农就曾指出，在某些情况下，为了实现最有效的通信，应采用具有白噪声的统计特性的信号。另外，为了实现高可靠的保密通信，也希望利用随机噪声。然而，利用随机噪声最大困难是它难以重复产生和处理。直到60年代，伪随机噪声的出现才使这一难题得到解决
(Pseudo-random code generator for VHDL realize communication with the development of the theory, as early as the 20th century, 40 years, Shannon has pointed out that in some cases, in order to realize the most effective communications, should be used with the statistical properties of white noise signal . In addition, in order to realize highly reliable secure communication, but also wish to take advantage of random noise. However, the use of random noise the greatest difficulty is that it difficult to repeat the generation and treatment. Until 60 years, the emergence of pseudo-random noise so that this problem only be solved)