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This paper presents BIFEST, an ATPG system that employs the built-in intermediate voltage test technique in an efficient ATPG process to deal with CMOS bridging faults. Fast and accurate calculations of the intermediate bridging voltages and the variant threshold tolerance margins on a resistive bridging fault model are presented. A PODEM-like, PPSFP-based ATPG process is developed to generate test patterns for faults that are conventionally logic-testable. The remaining faults are then dealt with by special circuits, called built-in intermediate voltage sensors (BIVSs). By this methodology, almost the same fault coverage as that employingIDDQtesting can be achieved with only logic monitoring required.

Current test resolution is confined by leakage elevation and variation in the nanometer static RAM. In this paper, we develop a novel scheme to highly improve the resolution by applying current test in power-gating sleep mode. A novel fine-grain power-gated adaptive-retention memory cell structure in the double threshold technology is designed for current testability. An LSB-selected decoder is also developed for fast test generation. Analyses on transistor level bridging faults prove the test effectiveness. The proposed scheme can explore the current resolution improvement up to the generic switch intensity ratio of the double threshold-voltage CMOS technology. From simulations in a 0.13 mum technology, the current resolution can be improved by about 40 dB, i.e., 100 times. Once current test can be renascent for embedded memory, the test time can be dramatically reduced.

Power gating using sleep transistors is a trend for power management and test scheduling in the deep-submicron and even nanometer resolutions. This paper develops a sleep transistor allocation structure that can not only reduce the spike-time product with data retention but also balance the noise margins and timing in active mode. A switching activity based model is developed as a heuristics for sleep transistor clustering. Under the proposed model, the spike reduction can be up to 83% in average

Power-gating is an effective approach for reducing both dynamic and static power dissipation in power management and test scheduling. This paper formulates the power-gating spike problem, derives a reduced power dissipation model as heuristics, proposes a vector control technique for post-gating circuits, and develops a sleep-transistor allocation scheme for power-on/off current spikes reduction of pre-gating systems. From experimental results, a justified controlling vector can reduce the on/off peak power up to 55%. For a pre-gating system, more than 83% of the power-gating spike can be reduced. From our preliminary simulations using HSPICE so far, this heuristics has been proved to reduce the supply-gating current spike

This paper presents the BIFEST, an ATPG system that combines the conventional ATPG process and the built-in intermediate voltage test technique to deal with CMOS bridging faults. A PODEM-like, PPSFP-based ATPG process that can effectively and efficiently model the bridging fault effects is developed to process those faults that are conventionally logic-testable. The remaining faults are then dealt with by special circuits called built-in intermediate voltage sensors. By this methodology almost the same fault coverage as that employing IDDQ testing can be achieved with only logic monitoring required.

Develops a low-power multiphase clock generator, employ static demultiplexers and proposes a hybrid design to reduce the power. The power model is based on the weighted transition count (WTC). The internal gates of a latch consume 2 transitions per cycle when the data changes. The clock and data input capacitances of a latch are assumed the same as that of a regular gate. A double-latch FF thus consumes 5 transitions including the interconnection between latches when the data changes.

A multiphase clocking technique is presented for reducing the test power for scan-based circuits. A novel scan cell design called the token scan cell is developed, which combines a phase-generating flip-flop and a data flip-flop to overcome the inter-phase skew and clock routing problems. Experimental results show that on average /spl sim/87% of the data transition count during scanning is reduced. For many circuits with long chains, a reduction of >98% can even be achieved.