March Pre: an Efficient Test for Resistive-Open Defects in the SRAM Pre-charge Circuit

Abstract

In this paper, we first present an exhaustive study on the influence of resistive-open defects in the pre-charge circuit of SRAMs. We show that these defects may disturb the pre-charge circuit, thus disturbing the read operation. This faulty behavior can be modeled by two types of dynamic faults called un-restored write faults (URWFs) and un-restored read faults (URRFs). For this type of faults, we next propose a new test algorithm called March Pre. The main advantage of March Pre is its complexity, which is twice lower (2.5N) than that of the reference MATS+ algorithm (5N). On the other side, an obvious shortcoming is that it targets only faults in pre-charge circuits. However, with its properties, March Pre makes the test but also the diagnosis easier in SRAM memories sensitive to pre-charge defects