Platform-Based Design for Embedded
Systems
Luca P. Carloni a Fernando De Bernardinis a,b Claudio Pinello a
Alberto L. Sangiovanni-Vincentelli a Marco Sgroi a,c
aUniversity of California at Berkeley, Berkeley, CA 94720-1772
bDipartimento di Ingegneria dell’Informazione, Universita` di Pisa, Italy
cDoCoMo Euro-labs, Munich, Germany
Abstract
A platform is an abstraction layer that hides the details of several possible implemen-
tation refinements of the underlying layers. It is a library of elements characterized
by models that represent their functionalities and offer an estimation of (physical)
quantities that are of importance for the designer. The library contains interconnects
and rules that define what are the legal composition of the elements. A legal com-
position of elements and interconnects is called a platform instance. Platform-based
design is a meet-in-the-middle process, where successive refinements of specifications
meet with abstractions of potential implementations that are captured in the models
of the elements of the platform. It is this characteristic that makes platform-based
design a novel design method.
We argue for the importance of structuring precisely the platform layers and we
discuss how to define formally the transitions from one platform to the next. In par-
ticular, we emphasize the interplay of top-down constraint propagation and bottom-
up performance estimation while illustrating the notion of articulation point in the
design process. In this context, we study the key role played by the API platform
together with the micro-architecture platform in embedded system design. Also, we
report on three applications of platform-based design: at the system-level, we discuss
network platforms for communication protocol design and fault-tolerant platforms
for the design of safety-critical applications; at the implementation level, we present
analog platforms for mixed-signal integrated circuit design.
Key words: Platform-based design, derivative design, embedded systems,
networks, protocol design, mixed-signal design, safety-critical applications.

1 Introduction
The motivations behind Platform-Based Design [29] originated from three ma-
jor factors that characterize the evolution of the electronics industry:
• The disaggregation of the electronic industry, a phenomenon that began
about a decade ago and has affected the structure of the electronics in-
dustry favoring the move from a vertically-oriented business model into a
horizontally-oriented one. In the past, electronic system companies used to
maintain full control of the production cycle from product definition to final
manufacturing. Today, the identification of a new market opportunity, the
definition of the detailed system specifications, the development of the com-
ponents, the assembly of these components, and the manufacturing of the
final product are tasks that are mostly performed by distinct organizations.
In fact, the complexity of electronic designs and the number of technologies
that must be mastered to bring to market winning products have forced
electronic companies to focus on their core competence. In this scenario,
the integration of the design chain becomes a serious problem whose most
delicate aspects occur at the hand-off points from one company to another.
• The pressure for reducing time-to-market of electronics products in the pres-
ence of exponentially increasing complexity has forced designers to adopt
methods that favor component re-use at all levels of abstraction. Further-
more, each organization that contributes a component to the final product
naturally strives for a position that allows it to make continuous adjust-
ments and accommodate last-minute engineering changes.
• The dramatic increase in Non-Recurring Engineering (NRE) costs due to
· mask making at the Integrated Circuit (IC) implementation level (a set of
masks for the 90 nanometer technology node costs more than two millions
US dollars),
· development of production plants (a new fab costs more than two billions
dollars), and
· design (a new generation micro-processor design requires more than 500
designers with all the associated costs in tools and infrastructure!)
has created the necessity of correct-the-first-time designs.
Major delays in the introduction of new products have been the cause of severe
economic problems for a number of companies. The cost of fabs have changed
the landscape of IC manufacturing forcing companies to team up for develop-
ing new technology nodes (for example, the recent agreement among Motorola,
Philips and ST Microelectronics and the creation of Renesas in Japan). The
costs and complexity of ASIC designs has caused several system companies
(for example, Ericsson) to reduce substantially or to eliminate completely their
IC design efforts. Traditional paradigms in electronic system and IC design
have to be revisited and re-adjusted or altogether abandoned.
2