1 A VHDL-Based Approach for Power Estimation of Embedded Systems William Fornaciari ^, Paolo Gubian *, Donatella Sciuto ^, Cristina Silvano * (^) Politecnico di Milano, Dipartimento di Elettronica e Informazione, P.zza L.Da Vinci, 32 - 20133 Milano, Italy, e-mail: {fornacia, sciuto}@elet.polimi.it, Fax:+39-2-2399 3411 (*) Univ. degli Studi di Brescia, Dip. di Elettronica per l’Automazione, Via Branze, 38 - 25123 Brescia, Italy, e-mail: {gubian, silvano}@bsing.ing.unibs.it, Fax: +39-30-380014 Keywords: Embedded Systems, Low Power Design, Power Estimation, VHDL, VLSI circuits. Contact author: William Fornaciari Abstract Power dissipation has become one of the main constraints during the design of embedded systems and VLSI circuits in the recent years, due to the continuous increase of the integration level and the operating frequency. The aim of this paper is to present an innovative conceptual framework suitable for achieving accurate and efficient estimation of power dissipation for embedded systems described in VHDL at the behavioral and Register Transfer levels. The goal is to provide the designer with the capability of analyzing and comparing different solutions in the architectural design space, before the synthesis. The analytical power model is hierarchical, considering the different parts of the target system architecture, mainly the data-path, the memory, the control logic and the embedded core processor. Experimental results have been obtained by applying the proposed power model to benchmark circuits. 1. Introduction An increasing number of applications in several fields like automotive, telecommunication, consumer electronics, etc. is recently being implemented by using embedded systems. These systems have become broadly used in the most recent years, due to the wide diffusion on the market of standard processors characterized by high performances and reasonable prices. We refer to embedded systems as those dedicated computing and control systems designed for specific target applications [28, 6], where dedicated software routines are provided with the system to respond to specific requirements. In general, the functionality of an embedded system is constituted by a fixed number of operating ways and it is determined by the interaction between the system and the environment. According to the particular application class for which the system is dedicated, the embedded systems can be classified as data or control dominated systems [28]. In both cases, the target system architecture is composed of an hardware and a software part. The software part is typically constituted by a set of application specific software routines running on a dedicated processor or ASIP (Application Specific Instruction Processor), while the hardware part consists usually of one or more ASICs (Application Specific ICs). Due to the heterogeneous nature of the hardware and software parts of the embedded system, innovative co-design techniques have been proposed in the recent past, the goal being to meet the system-level requirements by using a concurrent design and validation approach, thus exploiting the synergism of the hardware and the software parts [6]. Several design aspects are involved in the co-design process at the system-level, including the system modeling, the capture of the functional specifications in a high-level language (co-specification), the analysis and validation of the specifications, the exploration and evaluation of the different