A Fault Simulation Method for Crosstalk Faults in Synchronous Sequential Circuits

Noriyoshi ITAZAKI
Yasutaka IDOMOTO

IEICE TRANSACTIONS on Information and Systems   Vol.E80-D    No.1    pp.38-43
Publication Date: 1997/01/25
Online ISSN: 
Print ISSN: 0916-8532
Type of Manuscript: Special Section PAPER (Special Issue on Fault-Tolerant Computing)
Category: Testing/Checking
crosstalk fault,  fault simulation,  sequential circuit,  test,  

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With the scale-down of VLSI chip size and the reduction of switching time of logic gates, crosstalk faults become an important problem in testing of VLSI. For synchronous sequential circuits, the crosstalk pulses on data lines will be considered to be harmless, because they can be invalidated by a clocking phase. However, crosstalk pulses generated on clock lines or reset lines will cause an erroneous operation. In this work, we have analyzed a crosstalk fault scheme, and developed a fault simulator based on the scheme. Throughout this work, we considered the crosstalk fault as unexpected strong capacitive coupling between one data line and one clock line. Since we must consider timing in addition to a logic value, the unit delay model is used in our fault simulation. Our experiments on some benchmark circuits show that fault activation rates and fault detection rates vary widely depending on circuit characteristics. Fault detection rates of up to 80% are obtained from our simulation with test vectors generated at random.