- 學位論文
用於Flexray時脈同步的排序法硬體設計
A Hardware Design Approach of Sorting for Flexray-based Clock Synchronization
摘要
在現今使用的車輛中，電子控制單元(Electronic Control Unit, ECU)的數量，因為車輛電子化及安全性提高之需求，而不斷的上升；隨著車輛電子化之提高，車輛內部機構需要電子控制單元的協同控制及交換訊息，要有更高的傳輸效能、容錯、安全與穩定之車用網路通訊系統，此網路需要傳遞控制指令、單元狀態和資訊等，並且要能提供快速、安全及穩定之需求。Flexray為一種可以提供下一代高速傳輸和容錯需求的車用網路通訊協議，而Flexray通訊協定中的通訊控制器是它的核心模組，本論文將使用硬體描述語言Verilog來實現此部份；其中同步模組是通訊控制器中最為複雜的部份，同步模組的功能為透過計算對其他節點時脈偏移量，達到網路時脈的同步。其中使用的Fault-Tolerant Midpoint演算法需要針對觀察到節點的偏移量做排序整理，進而算出平均值，在這邊我們提出一個新的硬體排序模組，此種模組可在不需重新設計的情況下，利用排列相同硬體模組的方式，不斷的增加排序數量，而且此種排序模組在Flexray運作下相當穩定也相當符合其需求。
並列摘要
In automotive vehicles, the amount of electronic control units (ECUs) has been increased on the electronic vehicles and the demands of the safety. In the vehicles, we need to build a network to cooperate and transfer the message between the ECUs. The specifications of the vehicle networks are the high data-rate transmission, fault-tolerance, security and stability ECUs can deliver the electronic command, unit status, and information by the vehicle network. Flexray is the one of alterative methodology. It provides the high-speed networking and the fault-tolerant communication. The communication controller (CC) in the Flexray protocol is the core mechanism. We implement this design with Verilog HDL code. One of the most complicated parts of CC in the Flexray specification is the clock synchronization process (CSP) module. It uses to synchronize the ECUs in the global time of the in-vehicle cluster by the timing correction terms. The Fault-Tolerant Midpoint algorithm is adopted to calculate the timing correction terms from the list table of the measured offset and rate values. Since the algorithm calculates the timing correction terms with the midpoint of the sorted list, we propose an improved systematic architecture of the sorting. We can increase the amount of sorting item very easy without redesign a full new sorting network. And it works perfectly.