Journal of Embedded Computing 2 (2006) 1–3 1 IOS Press Embedded processors and systems: Architectural issues and solutions for emerging applications S. Bartolini a,1 , P. Foglia b,*,1 and C.A. Prete b,1 a Department of Information Engineering, University of Siena, Siena, Italy b Department of Information Engineering, University of Pisa, Pisa, Italy The design of embedded systems concerns hard- ware, software and mixed hardware-software issues. The increasing demand of complex consumer appli- cations, such as the management of multimedia con- tent and value-added services provided via mobile de- vices [1], is pushing towards the development of new architectures, operating systems and development en- vironments. Among the most promising architec- tures, there are heterogeneous systems on chip. In a typical design, such systems integrate microproces- sor(s)/microcontroller(s) and DSP cores. In them, mi- croprocessor(s)/microcontroller(s) are devoted to the execution of the control, coordination and interfacing parts of the application, DSP are devoted to the sup- port of numerically intensive tasks. Examples of this tendency can be verified in some commercial prod- ucts such as the Texas-Instrument OMAP or the At- mel Diopsis families, comprising integrated ARM/DSP cores [2,3]. This scenario requires studies on the chip architec- ture (e.g. how many units, which kind of units, in which way they communicate, how the chips are intercon- nected: these are some of the open questions [6–8]) and on the paradigms for synchronization/communication at hardware and software level. In addition, advances in development tools for the management and exploita- tion of the cross-interaction among cores are highly * Corresponding author. P. Foglia, E-mail: Foglia@iet.unipi.it. 1 Members of the HIPEAC EU network of excellence. desirable, starting from the system design phase up to the compilation, linking, run-time loading and tun- ing phases. Without such integrated approach, design- ers may be forced to make designing and optimizing choices for the different cores/modules singularly. This fact can cause an inefficient overall system even if it originates from the union of optimal subsets of design parameters [9,10,14]. Also the research concerning real-time OS needs to keep up with the increased complexity derived from the heterogeneous environment. This is a crucial point that needs to be solved, at least in terms of support provided by development environments. The new applications have to meet complex real-time requirements, and de- signers need of tools that support the easy implemen- tation and verification of such requirements. Without advances in this field, the increasing chip complexity will augment the difficulty in estimating worst-case ex- ecution times. This situation can induce designers to choose conservative and simple scheduling solutions, in order to be able to meet the application deadlines and, above all, to certify the timing features of the sys- tems [4,5]. This issue of JEC covers some of these challenges with articles on diverse aspects of embedded systems, focusing in particular on the architectural level. They are consequence of an open call for submission, and a selection of papers collected from various editions of the MEDEA workshop. This workshop, held in conjunction with the PACT conference since 2000, ISSN 1740-4460/06/$17.00  2006 – IOS Press and the authors. All rights reserved