This paper deals with the system-level performance analysis and optimization of a class of digital systems we call mixed asynchronous-synchronous systems. In such a system, each computation module is either synchronous or asynchronous. The communication between all the modules is assumed to be data-driven. In order to adequately describe the timing of such architectures, we introduce a graph mo...

The starting point of this paper is the asynchronous box calculus with multiway communication (MBC), a formalism suitable for modelling compositionally distributed systems using both synchronous and asynchronous communication and a number of control flow operators. MBC is composed of two semantically consistent models: an algebra of lowlevel Petri nets and an associate algebra of process terms ...

A collision problem is presented which can occur between two adjacent protocol entities, a user and its local provider. We consider synchronous and asynchronous communication mechanisms at the Service Access Point between the entities; this is normally an implementation choice. It is shown that even if the problem is limited by using a synchronous communication mechanism, instead of an asynchro...

A Gals (Globally Asynchronous Locally Synchronous) system typically consists of a collection of sequential, deterministic components that execute concurrently and communicate using slow or unreliable channels. This paper proposes a general approach for modelling and verifying Gals systems using a combination of synchronous languages (for the sequential components) and process calculi (for commu...

Analysis of Time Delays in Synchronous and Asynchronous Control Loops Björn Wittenmark, Ben Bastian , and Johan Nilsson email: [email protected], [email protected], and [email protected] Department of Automatic Control, Lund Institute of Technology Box 118, SE-221 00 Lund, Sweden Abstract In this paper we describe how to determine the time delays caused by synchronous and asynchronous co...

It is commonly argued that asynchronous computer-mediated communication (CMC) is preferable for promoting reflection and discussing complex ideas in e-learning environments. However, guidelines for when to use synchronous media are unavailable. In order to address this problem, we propose initial prescriptive guidelines for when to support synchronous communication, as a complement to asynchron...

An asynchronous circuit, or self-timed circuit, is a sequential digital logic circuit which is not enabled by a global clock signal. Instead of that, they often use signals that indicate completion of operations and instructions, specified by handshaking or simple data transfer protocols. This type is contrasted with a synchronous logic circuit where changes to the output signal values are trig...

Safety-critical embedded applications are often distributed. For example, software in an automotive control or in avionics control are distributed over a large number of distributed processors which are connected over some domain specific buses. Correctness of such applications is of paramount importance due to their safety-critical nature. Synchronous programming models (e.g. Esterel, SIGNAL, ...

Mobile communication has become a significant part of everyday life. The advent of mobile phones and PDA’s has reinforced the necessity for people to be connected without being physically tied down. Communication is key, but current modalities are restricted to simple protocols such as telephony, and less expressive mediums such as text messaging. TattleTrail is an archiving audio chat applicat...

Two network-on-chip (NoC) designs are examined and compared in this paper. One design applies a bidirectional ring connection scheme, while the other design applies a code-division multiple-access (CDMA) connection scheme. Both of the designs apply globally asynchronous locally synchronous (GALS) scheme in order to deal with the issue of transferring data in a multiple-clockdomain environment o...