GLFSR - A new test pattern generator for built-in-self-test

A new and effective pseudorandom test pattern generator, termed GLFSR, is i ntroduced. These are linear feedback shift registers (LFSR's) over a Galois field GF(2(delta)), (delta > 1). Unlike conventional LFSR's, which are ove r GF(2), these generators are not equivalent to cellular arrays and are sho wn to achieve significantly higher fault coverage. Experimental results are presented in this paper depicting that the proposed GLFSR can attain fault coverage equivalent to the LFSR, but with significantly fewer patterns. Sp ecifically, results obtained demonstrate that in combinational circuits, fo r both stuck-at as well as transition faults, the proposed GLFSR outperform s all conventional pattern generators. Moreover, these experimental results are validated by certain randomness tests which demonstrate that the patte rns generated by GLFSR achieve a higher degree of randomness.