Simulation and Visualisation for Debugging Large Scale Asynchronous Handshake Circuits

Janin,L.

Abstract

Recent advances in automated synthesis tools for asynchronous circuits have made possible the design of large self-timed circuits. However, these new tools are still weak in their behavioural simulation and debugging capabilities because asynchronous circuits pose different challenges and opportunities in these areas from conventional clocked circuits. Balsa is such a tool intended for the synthesis of large asynchronous circuits by using handshake circuits as an intermediate representation. This thesis addresses new simulation and visualisation techniques for debugging large scale asynchronous circuits at the handshake circuit level. It is based on extensive behavioural simulation and large scale visualisation of handshake circuits. A set of optimisation techniques applicable to the simulation of handshake circuits leads to a simulator four orders of magnitude faster than the previous Balsa simulator on large circuits. A visualisation system targeting program comprehension by efficiently tracking control flows is presented. It is based on two techniques: First, a graph-based view of the handshake circuit merges multiple sources of information to generate a graph viewable at any level of detail, with dynamic simulation results rendered atop it. Then, a collaborative scheme between multiple views allows the tracking of elements between views for efficient navigation. The framework is evaluated on the largest circuit described with Balsa so far, an ARM-compatible asynchronous microprocessor.

The thesis is available as PDF (6.8MB).