An inexpensive method of detecting localised parametric defects in static RAM

Abstract

The author presents an effective method of testing spot defects causing delay faults in SRAM circuits, without having to perform a full speed test of every single cell in a chip. The method is based on the detection of spot defects through the imbalance they cause to memory cells by transforming the imbalance effect into a permanent error. Such tests may be performed at a low speed, while retaining an excellent ability to detect non-catastrophic spot defects.<>