Title
PALS: Plesiochronous and Locally Synchronous Systems
Abstract
Consider an arbitrary network of communicating modules on a chip, each requiring a local signal telling it when to execute a computational step. There are three common solutions to generating such a local clock signal: (i) by deriving it from a single, central clock source, (ii) by local, free-running oscillators, or (iii) by handshaking between neighboring modules. Conceptually, each of these solutions is the result of a perceived dichotomy in which (sub)systems are either clocked or fully asynchronous, suggesting that the designer's choice is limited to deciding where to draw the line between synchronous and asynchronous design. In contrast, we take the view that the better question to ask is how synchronous the system can and should be. Based on a distributed clock synchronization algorithm, we present a novel design providing modules with local clocks whose frequency bounds are almost as good as those of corresponding free-running oscillators, yet neighboring modules are guaranteed to have a phase offset substantially smaller than one clock cycle. Concretely, parameters obtained from a 15 nm ASIC implementation running at 2 GHz yield mathematical worst-case bounds of 30 ps on phase offset for a 32 × 32 node grid network.
Year
DOI
Venue
2020
10.1109/ASYNC49171.2020.00013
2020 26th IEEE International Symposium on Asynchronous Circuits and Systems (ASYNC)
Keywords
DocType
ISSN
gradient clock synchronization,clocking,GALS
Conference
2643-1394
ISBN
Citations 
PageRank 
978-1-7281-5496-1
1
0.38
References 
Authors
13
5
Name
Order
Citations
PageRank
Bund Johannes110.38
Matthias Függer216721.14
Christoph Lenzen358440.61
Moti Medina410614.42
Rosenbaum Will510.38