OCP Protocol Bridge Design And UVM Verification

With the development of So C(System on Chip)technology,the research of So C has become the focus of IC industry.As for So C technology,the emphasis is to realize IP core reuse and system verification.However,as the design of IP cores is very different,in order to realize the communication between each other,it is necessary to transform the communication protocol between IP cores.In order to facilitate the design and implementation of IP cores and improve the reusability of IP cores,separate design is usually used to implement the protocol conversion part,namely the Bus Bridge.OCP(Open Core Protocol)and AXI(Advanced Extensible Interface)protocols are widely studied in the application of So C in today's bus protocols,which have high research value.Therefore,this paper will carry out research in the following aspects,including the design and implementation of OCP protocol into AXI protocol interface(OCP2AXI2)and UVM verification.The specific research contents are as follows.Firstly,two protocols(OCP and AXI)related to OCP2 AXI protocol bridge are analyzed and studied in this paper.Research priorities for in data flow,three Phase interface with OCP(request Phase,the response Phase,the data handshake)grouping of related signal and with the passage of the five independent AXI interface(including the read/write data channel,channel,read/write address written response channels)related signal,the signal encoding,sequence,a detailed study logic transmission and so on characteristics.Through the in-depth and thorough study of OCP protocol and AXI protocol,familiar with the two protocols in the implementation of the transmission mechanism differences,signal implementation similarities and differences and other details.Then on this basis,the study design the first OCP2 AXI Bus bridge,function structure,the specific function modules of the design including data output port design,address output port design,waiting for the write buffer design,waiting to be read buffer design and OCP interface signals to the AXI interface mapping design,completed the protocol conversion can be realized from the OCP interface to AXI interface protocols OCP2 AXI expected function.On the basis of the completion of single-to-single mapping,the OCP-SPL module which can map the signal of OCP port to two different AXI subsystem domains according to the requirements is designed and implemented,so as to realize the mapping of one OCP interface to two AXI interfaces,which makes the overall design have better application flexibility.On the basis of the design and implementation,in order to verify the functional correctness of RTL level design code,this paper based on UVM verification methodology,and coverage as the result oriented design and build a verification platform.In the concrete implementation,the verification requirements are firstly obtained by combining design analysis,and then the bottom-up module implementation method is adopted to design the specific verification components to complete the verification work of test excitation generation,excitation drive,correctness check and so on.At the same time,the functional coverage component is implemented to collect the functional coverage in the simulation process to evaluate the completeness of the verification work.Based on the verification function points extracted from the circuit design,the main functions such as separate read and write,burst transmission and port selection are verified.Finally,in order to make the coverage rate converge quickly to achieve the expected goal,Python scripts were designed to perform regression on test cases,which has shortened the verification cycle,and The code coverage has reached 97.46%,and the function coverage has reached 100%.In this paper,we design a protocol conversion bridge that can convert signals from OCP format to AXI format.At the same time,we design the OCP-SPL module based on the one-to-one interface mapping,to implement the OCP2AXI2 double bridge structure.This module has better practicability than OCP2 AXI one-to-one protocol conversion bridge.OCP-SPL module can be configured according to the actual requirements of the system to achieve one-to-many design.On this basis,a verification platform based on UVM is designed and built to verify the correctness of code functions,and a hierarchical component library from transaction level to function level is established,which has strong portability.