VLSI Design and Test Seminar

"Combining LOC and LOS Tests for TDF Coverage Improvement"
(Masters project defense)

Jie Zhou
ECE Masters Candidate

Wednesday, April 9, 2014
4:00 pm, 235 Broun Hall


Abstract: 
Transition Delay Fault (TDF) testing is increasingly becoming critical for advanced integrated circuits. To detect Transition Delay Fault (TDF), two test vectors are needed to be applied to circuit consecutively. Launch on Capture (LOC) and Launch on Shift (LOS) were proposed to test delay faults for sequential circuits. Fault coverage of LOC is lower compared to LOS because the second vector in LOC, which has lower controllability, is obtained from the circuit response to the first vector. LOS has higher fault coverage for delay faults because the second vector is obtained by one bit shift of the first vector. However, due to prohibitive cost causing by implementing fast scan enable signal, LOS is not considered in most situation. An approach of combining LOC and LOS is proposed to lower cost and improve the TDF coverage by using multiple scan enable signals.