Last June, I participated in the International Workshop on Reconfigurable and Communication-centric Systems-on-Chip (ReCoSoC), which took place in Montpellier, France. This was the sixth in a series of workshops that I helped to start back in 2005, together with Gilles Sassatelli and Manfred Glesner. It grew out of a cooperation project between TU Darmstadt (my former university) and the LIRMM laboratory in Montpellier, France. The main goal was to have a forum for academics doing research in Systems-on-Chip that are reconfigurable and/or communication-centric. Let me explain those terms one by one. Systems-on-Chip (usually known as SoCs) are a specific implementation style for embedded systems. Like all embedded systems, they have specific functionalities (usually related to a particular application domain, such as robotics or telecommunications), but they aim to integrate all that functionality on a single silicon die -- the chip. SoCs can integrate one or several processor cores, different types of memory, hardware accelerators (e.g. video codecs, cryptography engines), radio-frequency controllers, sensors (e.g. accelerometer), among other components, all on the same chip.
As SoCs grow complex, the on-chip interconnect structure becomes more and more important. After all, the multiple cores and components listed above must communicate with each other and with the external world. The “communication-centric” part of ReCoSoC deals with the challenges of designing and evaluating different types of on-chip interconnects. A recent development in that area is the concept of Networks-on-Chip, which I will cover in another blog post.
Even though SoCs can integrate plenty of functionality, there is always a cost associated to it. Therefore, it may not be efficient to have a particular function during the whole lifetime of the system, specially if it is used only in specific scenarios (e.g. video codecs are only needed when recording or displaying video). On the other hand, there are some functions which may be replicated during the lifetime of the system because the demand is too high to be satisfied by the initial resources. The concept of changing the SoC’s logical structure after it has been deployed is called reconfiguration, and this also a major topic in ReCoSoC.
This year’s ReCoSoC was the most successful so far, with more than 80 research paper submissions. A committee of 42 researchers evaluated all submissions (each submission was reviewed by 3-4 committee members) and selected 29 of them to be presented as full papers at the workshop. Another 21 were considered work in progress and were selected to be presented as posters. The workshop had more than 80 attendees, and included a number of invited talks beside the accepted papers and posters. My favourite talks were:
- the keynote on Embedded Compilation and Virtualization by Christian Bertin (from STMicroelectronics);
- a paper on Asymmetric Cache Coherency by John Shield, Jean-Philippe Diguet and Guy Gogniat (all from Uni Bretagne Sud, FR);
- a paper presented by my former PhD student Luciano Ost (now working at LIRMM), providing an overview of our design flow for NoC-based embedded systems and highlighting some of his latest contributions on dynamic task mapping;
- two papers describing optimisations for NoCs with time-division multiplexing (TDM) presented by Daniel Vergeylen and Angelo Kuti Lusala (Uni Cath Louvain, BE);
- a very interesting paper about the possibility of transmitting data in FPGAs using temperature variations (which has interesting implications to security and privacy). It was presented by Taras Iakymchuk and Krzysztof Kepa (from Nokia Siemens, PL);
- a poster on self-organising processing elements used to control mobile robots, presented by Laurent Rodriguez (ETIS-ENSEA, FR).
Another interesting point about this year's ReCoSoC is that it took place at the Faculté de Médecine in Montpellier. It is one of the oldest medical schools in the world, established in 1180 (Nostradamus studied there in 1529!) We were all amazed to see presentations about modern multicore embedded systems on a lecture theatre built centuries ago to teach anatomy… it still has an ancient dissection table with an oval marble top! (see the video below, which I made during one of the talks)
In June 2012, we will organise ReCoSoC here in York. We hope to keep up with the excellent quality of the technical contributions, and to have again a history-rich environment for the discussions, this time provided by the ancient city of York. I’ll post more information here as it becomes available.
