An analysis of power reduction techniques in scan testing

Abstract

Power consumption during scan testing is becoming a concern. Circuit switching activity during scan shifting is high and results in high average and instantaneous power consumption. This paper presents a scheme for reducing power and provides analysis results on an industrial design.

A reconfigurable power-conscious core wrapper and its application to soc test scheduling

“…Nicolai and AlHashimi [21] proposed a technique to minimize useless switches, and Gerstendörfer and Wunderlich [5] introduced a technique to disconnect the scan-chains from the combinational logic during the shift process, both leading to a lower power consumption during test, which reduces test time by allowing clocking at a higher frequency. For the same purpose, Saxena et al [24] proposed an approach to gate sub-chains.…”

“…The RPC (reconfigurable power-conscious) test wrapper we propose combines the gated sub-chain approach proposed by Saxena et al [24] and the reconfigurable wrapper introduced by Koranne [15]. The basic idea in the approach proposed by Saxena et al [24] is to use a gating scheme to lower the test power dissipation during the shift process.…”

“…The basic idea in the approach proposed by Saxena et al [24] is to use a gating scheme to lower the test power dissipation during the shift process. Given a set of scan-chains as in Figure 2 where the three scan-chains are connected into a single chain.…”

“…• design for low power testing where the system is designed to minimize test power consumption, which allows consequently testing at a higher clock frequency [5,21,22,24], and • test scheduling where the tests are organized in such a way that the test time is minimized while considering test power limitations and test conflicts [1,4,6,7,8,9,11,12,13,14,15,16,17,18].…”

“…• the development of a RPC core test wrapper which combines the gated sub-chain scheme presented by Saxena et al [24] and the reconfigurable core test wrapper introduced by Koranne [15], • the integration of the RPC wrapper in the preemptive test scheduling approach, and • the formulation of a power condition that, if satisfied, guarantees that our preemptive test scheduling scheme produces optimal test time.…”