On the testability of FFT arrays

This paper presents new approaches for testing VLSI array architectures used in the computation of the complex N-point fast Fourier transform. Initially, an unrestricted single cell-level fault model is considered. The first proposed approach is based on a process whose complexity is independent (or C- as constant) of the number of cells in the FFT architecture. This is accomplished by showing a topological equivalence between the FFT array and a linear (one-dimensional) array. The process of fault location is also analyzed. The second proposed method is based on a testing process whose complexity is linear with respect to the number of stages (columns) of the FFT array. A component-level fault model is also proposed and analyzed. The implications of this model on the C-testability process are fully described