Constant Function Independent Test Set for Fault Detection in Bit Parallel Multipliers in GF(2^m)

Abstract

In this paper, a C-testable implementation of polynomial basis (PB) bit parallel (BP) multiplier over the Galois fields of form GF(2 m) for detecting stuck-at faults in multiplier circuits has been proposed. The length of the constant test set is only 8. The fault detection can be incorporated in the multiplier circuit with only three extra inputs for controllability. The gate counts of the proposed testable multiplier as a function of degree m is also analyzed. The proposed constant test set is much smaller than ATPG generated or algorithmic test set, resulting in low power testability. As the GF(2 m) multipliers have found some critical field applications and need for efficient online testing, built-in self-test (BIST) circuit is proposed to generate test pattern internally. This BIST also obviates the need of having three extra pins for the control inputs. Area and delay of testable circuits and BIST circuit is analyzed using 0.18mum CMOS technology library from UMC. The proposed test pattern has the intrinsic ability to detect single bit errors in the test pattern generator (TPG) itself. The test set provides 100 percent single fault coverage