Today's SoCs are composed of a high variety of modules, such as microprocessor cores, memories, peripherals, and customized blocks directly related to the targeted application. Testing a peripheral core embedded in a SoC requires two correlated phases: module configuration and module operation. The first one prepares the peripheral on the different operation modes, whereas, the second one is in charge of exciting the whole device and observing its behavior. Different testing strategies based on the execution of assembly programs have been proposed by the research community to test the embedded blocks in a SoC, however, testing highly embedded peripherals (e.g., DMA controllers) is still a challenging task, since their observability and controllability are even more reduced compared to peripherals devoted to I/O communication. In this paper we describe an approach to develop functional tests for DMA controllers embedded in SoCs that can first be used for design validation, and then exploited for testing, adding observability features. Preliminary experimental results demonstrating the method suitability are finally reported.