Book Description

Transient current (iDDT) refers to the current drawn from the power supply durin g the transient switching of CMOS gates. Testing based on the transient current can detect many of the defects that can occur in ICs, such as resistive opens, w hich may not be detected by traditional voltage testing or by Leakage current (I DDQ) testing methods. A major set back for IDDQ testing methods is the increased leakage currents in today's ICs. Thus iDDT based testing has been often investi gated as an alternative or supplement to (IDDQ) testing. Little work has focused on iDDT testing for domino circuits. In this thesis, we propose a method for testing domino CMOS circuits using the transient power supp ly current. The method is based on monitoring the peak value of the transient cu rrent. This peak varies considerably with process variations, so each process ha s different thresholds; this problem will be addressed by proposing a normalizat ion procedure that allows us to use a single threshold for all processes. We pre sent also a test vector generation algorithm for testing large domino circuits. We evaluate the effectiveness of this testing method by simulation on various do mino circuits of different sizes. We develop and implement a partitioning technique to improve the fault coverage of the test method when used with large circuits. The algorithm divides the circ uit into different clusters where each cluster is fed by a different power suppl y branch. We also provide an automation system to simplify the process of genera ting the simulation files, injecting the defects in the circuit, running the sim ulations, storing the simulations output, processing the output signals, and fin ally gathering and analyzing the results.