Constructing augmented time compactors

Abstract

In this paper, a procedure for constructing time compactors based on a new 3-dimensional augmented product code is presented. Accordingly, augmented time compactors are constructed by assigning a unique triplet <x,y,z> to each scan chain and calculating at least four sets of parity check bits. Each set of parity check bits is attached to one or more multi-input shift registers (MISRs). The proposed procedure allows an efficient construction for different classes of time compactors as well optimization and comparison of their properties. The constructed augmented time compactors demonstrate an ability to achieve a much higher compaction ratio than convolutional and modular compactors.

Enhancing Superset $X$ -Canceling Method With Relaxed Constraints on Fault Observation

“…A third approach is to design an X-tolerant compactor that can compact an output stream that contains Xs without the need for X-masking. X-tolerant compactors have been developed based on linear combinational compactors [6], [7], [15], [16] that are mainly based on the application of systematic linear codes. Convolutional compactors [12] and circular registers [3], [6], [7] can tolerate a certain amount of X values.…”

“…X-tolerant compactors have been developed based on linear combinational compactors [6], [7], [15], [16] that are mainly based on the application of systematic linear codes. Convolutional compactors [12] and circular registers [3], [6], [7] can tolerate a certain amount of X values. Although multiple-input signature registers (MISRs) are the most efficient for compacting output streams without Xs, they present difficulties when Xs are present because even a single X can corrupt the MISR contents with its sequential nature in accumulating its signature [6], [7].…”