The Research On Verification Method Of A Multi Channel DMA Controller

The DMA controller is one of the most commonly used components in a SoC system.Its main function is to quickly transfer data without control of CPU.With the development of SoC system,the complexity of DMA controller has gradually increased.The traditional verification method which use directed test has been unable to verify all functions of the DMA controller.The emergence of the UVM(universal verification method)has solved this problem.Based on the module-level verification of a DMA controller IP core,this thesis firstly analyzes the history of verification methodology.Due to the characteristics of high automation degree and strong reusability,UVM is selected as the theoretical basis to build the verification platform in this thesis.Then,this thesis conducts an in-depth research of the verification components,communication methods,and important mechanisms of the UVM.After analyzing and understanding the principles,this thesis explores the functional characteristics of the DMA controller in detail,clarifies the work flow of DMA,summarizes the composition of the register module of DMA,and studies the polling mechanism of DMA in multi-channel transmission.Finally,this thesis determines a priority-based polling arbitration mechanism of DMA.With the beginning of the verification of the DMA controller,this thesis first develops a verification plan.Based on the in-depth understanding of the DMA controller,the verification function points are extracted,and test cases are planned to cover each function point.Then,using UVM,a DMA controller verification platform with UVM standard tree structure is constructed.This thesis introduces the overall structure of the verification platform,and researches and analyzes the creation and connection methods of each verification component.The DMA controller verification platform built in this thesis mainly includes an apb?master?agent for configuring registers,two ahb?slave?agents for sending or receiving data,one peripheral?agent for simulating peripheral sending requests,one socreboard for comparing the correctness of the transmitted data and confirming the correctness of the DMA function,one arbiter?rfm for verifing the correctness of the polling arbitration mechanism,one top-level environment and one register model,etc.;At last,based on the verification function points,this thesis writes the constraints of configuration and random test cases,and starts the verification platform,simulates and verifys the DMA controller.During the simulation process,multiple design bugs of DMA controllers are discovered through automatic comparison of the verification platform or the way of artificial observation of the transmission waveform,and these bugs are promptly submitted to the designer for correction,so that the design is continuously improved during the entire verification process.When the verification platform no longer reports errors and the random test cases are stable after multiple runs,this thesis begins to collect the coverage of the DMA controller.Combining with the analysis of the collected results,using the method of adding directional test and ignoring redundant code,the function and code coverage of DMA controller reached 100%,which shows that the DMA controller has realized all the functions in the function description document,and the verification work in this thesis also fully cover all function points.The above results are in line with the expected goals.The verification results in this thesis show that the efficiency and completeness of the DMA controller verification using UVM are both high.The verification platform built in this paper also has the characteristics of clear hierarchical structure,high reuse of components,high independence of components,simple incentive generation method and rich incentive generation results,which has certain reference significance for the creation of verification platform for other key components in the SoC system.