ThruChip Interface for Heterogeneous Chip Stacking

Abstract

This paper presents a wireless inter-chip link using inductive coupling, namely ThruChip Interface (TCI). TCI is a digital CMOS circuit solution in a standard CMOS technology. It is much less expensive than TSV (Through Silicon Via) but bears comparison in performance. Delay time and energy dissipation will scale down by scaling device size and chip thickness. As the inductive coupling enables interface among chips under different supply voltages, TCI is suitable for heterogeneous integration. A 90nm 8-core processor under 1.0V power supply and two 65nm SRAM's under 1.2V power supply are stacked and AC-coupled by TCI at 19.2Gb/s. Power dissipation and area efficiency of the link is 1pJ/b and 0.15mm2/Gbps respectively, which is 1/30 and 1/3 in comparison with the conventional DDR2 interface.