Near-Optimal Node Selection Procedure for Aging Monitor Placement

Transistor and interconnect wearout is accelerated with transistor scaling resulting in timing variations and consequently reliability challenges in digital circuits. With the emergence of new issues like Electro-migration these problems are getting more crucial. Age monitoring methods can be used to predict and deal with the aging problem. Selecting appropriate locations for placement of aging monitors is an important issue. In this work we propose a procedure for selection of appropriate internal nodes that expose smaller overheads to the circuit, using correlation between nodes and the shareability amongst them. To select internal nodes, we first prune some nodes based on some attributes and thus provide a near-optimal solution that can effectively get a number of internal nodes and consider the effects of electro-migration as well. We have applied our proposed scheme to several processors and ITC benchmarks and have looked at its effectiveness for these circuits.