A Low-Overhead Method for Pre-bond Test of Resonant 3-D Clock Distribution Networks

Designing a low power clock network in synchronous circuits is an important task. This requirement is stricter for 3-D circuits due to the increased power densities. Resonant clock networks are considered efficient low power alternatives to con- ventional clock distribution schemes. These networks utilize ad- ditional inductive circuits to reduce power while delivering a full swing clock signal to the sink nodes. Test is another complex task for 3-D ICs, where pre-bond test is a prerequisite. Contactless test has been considered as an alternative for conventional test methods. This paper, consequently, introduces a design method- ology for resonant 3-D clock networks that supports wireless pre- bond testing through the use of inductive links. By employing the inductors comprising the LC tanks of the resonant clock net- works as the receiver circuit for the links, the need for additional circuits and/or interconnect resources during pre-bond test is essentially eliminated. The proposed technique produces low power and pre-bond testable 3-D clock distribution networks. Simulation results indicate 98.5% and 99% decrease in the area overhead and power consumed by the contactless testing method as compared to existing methods.