Using GLFSRs for pseudo-random memory BIST

We present the application of Generalized Linear Feedback Shift Registers (GLFSRs) for generation of patterns for pseudo-random memory built-in self-test (BIST). Recently, it was shown that using GLFSRs as pattern generators for pseudo-random logic tests can increase the fault coverage noticeably in comparison to standard pseudo-random test pattern generators. Since memory faults differ from logic faults, we examined if that is also the case for pseudo-random memory tests. We found that GLFSRs can increase the fault coverage of pseudo-random tests for several fault types, especially for complex faults as stuck-open faults. Thus, the usage of GLFSRs as pattern generators for pseudo-random memory testing is recommended although some area overhead has to be accepted