Clock clustering and IO optimization for 3D integration

Abstract

3D interconnect between two dies can span a wide range of bandwidths and region areas, depending on the application, partitioning of the dies, die size, and floorplan. We explore the concept of dividing such an interconnect into local clusters, each with a cluster clock. We combine such clustering with a choice of three clock synchronization schemes (synchronous, source-synchronous, asynchronous) and study impacts on power, area and timing of the clock tree, data path and 3DIO. We build a model for the power, area and timing as a function of key system requirements and constraints: total bandwidth, region area, number of clusters, clock synchronization scheme, and 3DIO frequency. Such a model enables architects to perform pathfinding exploration of clocking and IO power, area and bandwidth optimization for 3D integration.