PickHDB3 yards ( third-order high-density dual polarity yards) is the most commonly used in modern transmission system is one of the MaXing， is widely This study is based on the main content of the HDB3 yards encoder CPLD device First of HDB3 yards and CPLD application and research status were introduced， This paper used to MaxPlusII and VHDL language software， Finally HDB3 yards are analyzed in detail by VHDL language encoding principle and realization Based on the principle of coding HDB3 yards， the paper analyzes the design scheme of HDB3 code design mainly divided into three coder realized module ( insert V module， modeling and realize the modeling and realization， B module modeling and realize polarity transform module) After completion， the software design in the simulation， MaxPlus2 test results and the design idea of early， so right， completed based on simulation HDB3 code design of CPLD Keywords: HDB3， VHDL， Polarity transformation
SummaryHDB3 code (that is， the third order high-density bipolar code) is a modern transport system in the most common code， application is very The main content of this article is based on the CPLD HDB3 encoder First of all on HDB3 codes and CPLDs development are discussed in this article， and to the software used and the introduction of VHDL language MaxPlusII; finally a detailed analysis of the principle of coding HDB3 codes and VHDL HDB3 codes by coding theory analysis， this design on HDB3 encoder design are divided into three modules step-by-step implementation (Plug-and-V module modeling and implementing the modeling and implementing module B， polar transform module modeling and implementation) Complete the design content in software MaxPlus2 on simulation， testing results and design ideas at the start of the match， so the simulation is correct， complete based on the CPLD HDB3 encoder
