A simple method of HDB3 coding based on FPGA
Shao Xiang Xin · Applied science and technology · 2007
The HDB3 code(High Density Bipolar Order 3 Encoding) keeps the feature of polarity inversion of AMI code,and reduces the length of zero strings,therefore benificial for extraction of timing message.Through the analysis of principle of HDB3 coding,a new coding way is proposed based on FPGA,and the realization method and simulation waveform are offered.This method adopts 2bit binary coding,which keeps the polarity inversion while inserting which the destroyed symbol so that the programming process is simplified.The operational speed is fast,and time delay is relatively small.Because of the characteristic of reprogramming of FPGA,this method has high flexibility,low development cost,stable and reliable operational property and easy debugging.