Developing mesochronous synchronizers to enable 3D NoCs

Abstract

The NETWORK-ON-CHIP (NOC) interconnection paradigm has been gaining momentum thanks to its flexibility, scalability and suitability to deep submicron technology processes. The next challenge is to use NoCs as the backbones of the upcoming generation of 3D chips, assembled by stacking multiple silicon layers. Multiple technical issues have to be tackled in this respect. One of the foremost is the unsuitability of a purely synchronous design style, as it is not straightforward to impose a strict bound on the clock skew among multiple clock trees across different layers. In this paper, we present a scheme to handle mesochronous communication in 3D NoCs and analyze (i) the circuit design, (ii) the timing properties, (iii) the requirements to support flow control across mesochronous links, (iv) the implementation cost of such a scheme after placement and routing.

TSV-virtualization for Multi-protocol-Interconnect in 3D-ICs

“…Synchronous global clock distribution networks like three dimensional extension of H-trees are hard to realize and will very unlikely be a suitable solution for chip wide clock distribution in future 3D-ICs [5]. Thus, a fully synchronous 3D-IC is not a realistic scenario.…”

“…Mesochronous synchronizers can be realized with less chip area and show a smaller delay. The synchronizers are built according to [5].…”