Design of Asynchronous Circuits by Synchronous CAD Tools

The roadblock to wide acceptance of asynchronous methodology is poor CAD support. Current asynchronous design tools require a significant re-education of designers, and their features are far behind synchronous commercial tools. This paper considers a particular subclass of asynchronous circuits (Null Convention Logic or NCL) and suggests a design flow that is based entirely on commercial CAD tools. This new design flow shows a significant area improvraent over known flows based on NCL

Continuous Query Processing and Dissemination

Traditional database information monitoring techniques, such as database triggers, active DBMS and continuous queries have various limitations, can not provide large scale dynamic data push and have no efficient data dissemination support. Meanwhile, current dissemination systems, which are separated from database, can not handle complicated query requests, such as aggregate operation. Also, as a middleware, it adds more overhead to the data querying. We designed, implemented and analyzed the first efficient active lightweight DBMS which also has full dissemination features built-in. We proposed a novel technique: record-based triggering, for efficient monitoring of clients ’ interested records known a priori. Also we use message passing for communication between clients and database servers. Unlike table-based triggering in current commercial database systems, record-based triggering gives much better scalability as well as speed. Meanwhile, compared with traditional communication mechanism as remote procedural call, message passing give full control to the active DBMS system, thus it can optimize the data processing and dissemination. The system, called Continuous Query Processing and Dissemination (CPQD), has been implemented in Java and is portable, extensible and scalable. Compared with traditional periodic pull techniques, the experiments results are very promising. 1

From synchronous to asynchronous: an automatic approach

This paper presents a methodology to derive asynchronous circuits from optimized synchronous circuits by replacing the clock distribution tree by a handshaking network. A case study shows the applicability of the method and the potential benefits of de-synchronizing synchronous circuits.Peer Reviewe

Handshake protocols for de-synchronization

De-synchronization appears as a new paradigm to automate the design of asynchronous circuits from synchronous netlists. This paper studies different protocols for de-synchronization and formally proves their correctness. Taxonomy of existing protocols for latch controllers is provided. In particular, four-phase handshake protocols devised for micro-pipelines are studied. A new controller with maximum concurrency for de-synchronization is also proposed. The applicability of de-synchronization on an implementation of the DLX microprocessor is also described and discussed.Peer Reviewe