06/01/1995 09:00 AM
Computer Engineering
Two-dimensional arrays are suitable for VLSI implementation because of their regular structure and relative ease of test. We provide test sets proportional to the sum of the two dimensions of the array for a large class of cells, which allow us to test rows (or columns) of cells of the array independently. Previous research has found constant length test sets for array multipliers under the single faulty cell model if the array is modified and otherwise test sets are proportional to the number of cells. We can verify the full adder array of a combinational n X m multiplier in O(n+m) tests under the Multiple Faulty Cell (MFC) model. We show that no constant length test set exists for this array under the MFC model. The entire multiplier, including the AND gates which generate the summands, can be verified after applying the same modifications which make the multiplier C-testable under the single faulty cell model. Finally we show an error in the proof of a commonly accepted theorem involving testing two-dimensional arrays for multiple faults.