Pondering the SoC platform

Pondering the SoC platform
By Richard Goering, EE Times
February 19, 2002 (6:36 p.m. EST)
URL: http://www.eetimes.com/story/OEG20020219S0011

Many people have been talking about platform-based design as the next big trend in the system-on-chip (SoC) world, but clear definitions are lacking. A new paper by one of the concept's originators should help cut through some of the confusion.

In a paper published on our www.EEdesign.com site, Alberto Sangiovanni-Vincentelli, professor at the University of California at Berkeley, sets forth the principles behind platform-based design and offers formal definitions. While "platforms" have been around for some time, Sangiovanni-Vincentelli and his colleagues pioneered the SoC platform concept as part of their work with the Gigascale Silicon Research Center.

The fundamental idea is abstraction. Basically, a platform is an "abstraction level" tha t hides unnecessary details from the designer. In the PC world, the paper explains, there's a standard platform that includes the X86 instruction-set architecture, specified buses and I/O devices.

Today, SoC platforms are being developed for such applications as networking or multimedia. An SoC platform might contain a predetermined microprocessor, OS, bus architecture and various intellectual-property blocks. Add embedded software and, perhaps, some custom hardware, and you can quickly produce a chip without having to design the whole thing from scratch.

Much of the Gigascale Silicon Research Center's work focuses on purely programmable platforms, in which all the customization is handled through embedded software and FPGA-type logic. But SoC platforms could also take more of a hardware-centric approach. The key, in any case, is the reuse of precharacterized, predesigned components.

In pursuit of a common lexicon, Sangiovanni-Vincentelli's paper defines basic concepts. A "platform st ack" consists of two platforms and the tools and methods used to map from the higher level of abstraction to the lower. An "architecture platform" is aimed at a specific application and is derived from a predetermined microarchitecture. An "API platform," or programmer's model, provides a high-level interface to the hardware.

A "system platform stack" provides mapping to the architectural platform, and a "silicon implementation platform stack" takes it down to silicon. The paper introduces the concept of a "network platform," which consists of nodes and channels.

Why is this important? Because the next leap in design productivity won't come from tools-it will come from new ways of thinking about silicon. This paper presents one of them.