Study of Parallel Encoder and Decoder of BCH

[[abstract]]隨著錯誤控制碼的發展，早期由漢明碼、索羅門碼一直到目前熱門的BCH碼，錯誤控制碼的技術目前算是相當成熟，傳統序列的BCH碼，需等待完全的碼長傳輸完方可進行編碼解碼，對平行傳輸架構,在時間利用上相當浪費。本論文擬開發平行化架構的BCH碼,並以硬體實現之,使可滿足即時性多位元傳輸之需求,對於高速運作下的Nand flash配合度更加契合。 本論文以(7,4)BCH碼及可更正1位元為雛型架構,平行化實現BCH碼,觀察並記錄每個位元流動情形 , 在編碼部分我們使用LFSR架構的編碼器作平行展開,在解碼器這邊我們將找syndrome的電路作平行展開,接著再利用得到的syndrome vector所對應的錯誤位置去做更正的動作。我們實驗藉由觀察並記錄序列(7,4)BCH碼每位元流動情形, 並在Xilinx平台模擬平行化架構的BCH碼,(7,4)實驗結果顯示編碼平行4bits架構執行時間上是傳統序列的4倍,成本上僅提升1.667倍,而解碼平行7-bit更是傳統序列的7倍, 成本上僅提升1.276倍。平行化編碼可達50Mb/s,解碼10Mb/s。[[abstract]]With the error control code development, early by the Hamming code, Reed-Solomon Code have the current popularity of BCH codes, error control code is quite a mature technology now, the traditional sequence of BCH codes, need to wait for the full transmission code length before End for encoding and decoding, the parallel transmission structure, use quite a waste of time. This is paper attempts to develop parallel architecture of the BCH code and to hardware implementation, so many dollars to meet the immediate transfer of the demand for high-speed operation of the Nand flash with degrees under more fit. This is paper used (7,4) BCH code and can correct 1 bit for the prototype structure, the parallel realization of BCH codes, observed and recorded every bit flow situation, the coding part of the framework we use LFSR encoder for parallel , in the decoder side we find a parallel circuit syndrome start, followed by the syndrome vector use the wrong location to do the corresponding correction actions. We observe and record the sequence of experiments by (7,4) BCH code for each element flow conditions, and parallel simulation in Xilinx platform architecture BCH code, (7,4) The experimental results show that code execution time on parallel 4bits architecture is the traditional sequence of 4 times the cost of the upgrade is only 1.667 times, and decoding parallel to the traditional 7-bit sequence is 7 times the cost of the upgrade is only 1.276 times. Parallel encoding up to 50Mb / s, decode 10Mb / s