Massimo Violante

High-level and hierarchical test sequence generation

Test generation at the gate-level produces high-quality tests but is computationally expensive in the case of large systems. Recently, several research efforts have investigated the possibility of devising test generation methods and tools to work on high-level descriptions. The goal of these methods is to provide the designers with testability information and test sequences in the early design stages. The cost for generating test sequences in the high abstraction levels is often lower than that for generating test sequences at the gate-level, with comparable or even higher fault coverage. This paper first analyses several high-level fault models in order to select the most suitable one for estimating the testability of circuits by reasoning on their behavioral descriptions and for guiding the test generation process at the behavioral level. We assess then the effectiveness of high-level test generation with a simple ATPG algorithm, and present a novel high-level hierarchical test generation approach to improve the results obtained by a pure high-level test generator.

A Low-Cost Solution for Deploying Processor Cores in Harsh Environments

Nowadays, a number of processor cores are available, either as soft intellectual property (IP) cores or as hard macros that can be employed in developing new systems on a chip. Developers of applications targeting harsh environments like the atmospheric radiation environment or the space radiation environment may benefit from the computing power of processor cores, provided that suitable techniques are available for guaranteeing their correct operations in presence of the ionizing radiation that abounds in such environments. In this paper, we describe a design flow and hardware/software architecture to successfully deploy processor IP cores in harsh environments. Experimental data are provided that confirm the robustness of the presented architecture with respect to transient errors induced by radiation and suggest the possibility of employing such architectures in deep-space exploration missions.