Jump Simulation: A Technique for Fast and Precise Scan Chain Fault Diagnosis

Abstract

A diagnosis technique is presented to locate seven types of single faults in scan chains, including stuck-at faults and timing faults. This technique implements the Jump Simulation, a novel parallel simulation technique, to quickly search for the upper and lower bounds of the fault. Regardless of the scan chain length, Jump Simulation packs multiple simulations into one so the simulation time is short. In addition, Jump Simulation tightens the bounds by observing the primary outputs and scan outputs of good chains, which are ignored by most previous techniques. Experiments on ISCAS'89 benchmark circuits show that, on the average, only three failing patterns are needed to locate faults within ten scan cells. The proposed technique is still very effective when failure data is truncated due to limited ATE memory.

Diagnosis of Multiple Scan-Chain Faults in the Presence of System Logic Defects

“…1-2-5-8-10 b9 b8 b7 b4 b6 b5 b3 b2 b1 10 1-3-7-9-10 b10 b8 b9 b4 b6 b5 b7 b2 b3 b1 (r1) 11 1-2-4-8-10 b11 b10 b9 b8 b6 b5 b7 b4 b3 b2 (r2) 12 1-3-6-9-10 b12 b10 b11 b8 b6 b9 b7 b4 b5 b3 (r3) 13 1-2-5-8-10 b12 b11 b8 b10 b9 b7 b6 b5 b4 (r4) 14 1-3-7-9-10 b12 b8 b10 b9 b11 b6 b7 b5 (r5) 15 1-2-4-8-10 b12 b10 b9 b11 b8 b7 b6 (r6) 16 1-3-6-9-10 b12 b10 b11 b8 b9 b7 (r7) 17 1-2-5-8-10 b12 b11 b10 b9 b8 (r8) 18 1-3-7-9-10 b12 b10 b11 b9 (r9) 19 1-2-4-8-10 b12 b11 b10 (r10) 20…”

“…Software-based methods algorithmically analyze the test data for diagnosis. These can be further broken down into two broad sub-categories: (1) simulation based in which available test patterns are fault simulated and analyzed [2,4,12], and (2) deterministic diagnostic pattern generation (DDPG) based which target individual scan cells on a faulty scan chain for test generation [13,15].…”

Diagnose Multiple Stuck-at Scan Chain Faults

“…In [KAO06], the authors proposed to pack multiple simulations into one run so the simulation time can be reduced. For each failing pattern, multiple simulations were performed to quickly search multiple segments of upper and lower bounds of the fault.…”

“…Note that compared to the jump simulation proposed in [KAO06], we injected one fault at a time and used parallel pattern simulation plus binary search. The method in [KAO06] simulated one pattern at a time and used parallel fault simulation.…”

“…The method in [KAO06] simulated one pattern at a time and used parallel fault simulation. If the number of failing patterns is larger than 32, parallel pattern simulation plus binary search can be more efficient.…”