Functional Verification of DMA Controllers

Today’s SoCs are composed of a wide variety of modules, such as microprocessor cores, memories, peripherals, and customized blocks directly related to the targeted application. To effectively perform simulation-based design verification of peripheral cores, it is necessary to stimulate the description in a broad range of behavior possibilities, checking the produced results. Different strategies for generating suitable stimuli have been proposed by the research community to functionally verify these modules and their interconnection when embedded in a SoC: however, their verification often remains a largely manual and unstructured operation. In this paper we describe a general approach to develop concise and effective sets of inputs by modeling the configuration modes of a peripheral with a graph, and creating paths able to cover all of its nodes: proper stimuli for the device are then directly derived from the paths. The resulting inputs sequences are aimed at design verification of system peripherals such as DMA controllers, and can be applied via simulation by means of dedicated testbenches or by setting up an environment including a processor, which executes a proper test priogram. In the latter case, the developed programs can be exploited in later stages for testing, by adding suitable observability features. Experimental results demonstrating the method effectiveness are reported.