Scheduling of Pipelined Data Paths for On-line Testability

Abstract

Abstract This paper presents a time-constrained scheduling of a pipelined data path with the perspective of improving on-line testability. The testability is incorporated at the scheduling phase of the synthesis. Being a presynthesis method, the approach minimizes the area overhead. Operations of the same type are assigned to resources called functional units (FU). The on-line testing is carried out by capturing selective input and output variables of a circuit under test (CUT) in time frames called passes. The captured variables are shifted out to an external testing unit for verification. Each FU of the CUT is tested at least once in each pass. Minimizing the number of variables needed to test all FUs reduces the testing time. Thus, the scheduling is performed with the objective of improving on-line testability by minimizing the number of FUs and the number of variables needed to test all FUs. Promising results are obtained on benchmark examples.