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The Hot Chips Symposium at Stanford’s University has barely kicked off and already we have a major bombshell from Tilera, namely their TILE64 multi-core processor.  We are not talking four or eight cores here but a whopping 64 full-featured identical cores, each with an integrated L1 and L2 cache, a distributed L3 cache, and an integrated non-blocking switch which is utilized to connect to the iMesh on-chip network.  The iMesh network is Tilera’s implementation of the grid architecture concept, with several enhancements of course, and allows the cores to communicate with each other as well as the main memory and the I/O. Since the cores are full-featured, each is capable of running an independent operating system. The general architecture of the TILE64 is shown in the illustration below.

Combined with a portfolio of 40 patents and the architecture described above, Tilera claims to be able to deliver 40X times the performance of the leading Texas Instruments DSP.  The TILE64 comes in several flavors running between 600MHz and 1GHz.  At these frequencies each core dissipates between 170 and 300mW, respectively.  Assuming the latter frequency, the chip would dissipate around 20 Watts without any of the peripheral circuitry or the network overhead. My guess is that the complete chip consumes at least 30 Watts, this however is pure speculation, since no average or maximum power dissipation numbers are available on Tilera’s website. Also missing from the website are the chip dimensions and the manufacturing node that is currently being utilized – two metrics that are of most interest to designers.

As discussed in previous posts, a multi-core chip is nothing without a good development environment that allows the programmer to take advantage of all the resources. Not to be outdone by other startups in the multi-core race, Tilera offers a Multicore Development Environment (MDE) that is based on the open-source Eclipse IDE, an ANSI C compiler, and a full system simulation model.  There are plans for the environment to support C++ soon as well.  In the meantime, the MDE enables developers to for example cluster cores, such that a particular application can obtain enough processing power. Of course, all this processing power and flexibility does not exactly come cheap, starting at $435 in 10K quantities. There are also plans for a 120 core device and a 36 core device, so we will definitely be hearing more from Tilera in the near future.

Not so long ago, the name of the game and the claim to fame was processor speed and megahertz. But as with most technology related things, the landscape changes quickly. These days, it is all about who can do more with less; less power that is. To approach this challenge, companies have to some degree been simplifying their cores, and instead of raising the megahertz count have been increasing the core count. The argument being, that several cores running slower but in parallel are more efficient than one core running at maximum speed, from the throughput and power envelope level point of view. However, it does not take a genius to figure out that if you put enough cores onto a single die, the power envelope per core decreases if the overall power for the chip is to stay the same.  Additionally, as you increase the core count, the die area for the chip is likely to increase, which can lead directly to yield problems.  A less leaky process and smaller feature sizes are no substitute for sound power management techniques and smart design. Addressing this very issue, Heinrich Hillmayr from Texas Instruments’ (TI) German division, posted an interesting article titled Minimizing Power Consumption at the Chip Level over at PowerManagementDesignLine.com (This must be one of the longest domain names I’ve ever come across!). If you are a seasoned circuit designer you can skip the first page of the article which briefly describes the basic relationships between voltage, leakage and dynamic currents, and power. If not, this might be a nice little review especially if you have an interview coming up. The second page is where the article gets interesting. In a perfect world there would be neither variation in a waver nor any variation between wavers, but semiconductor manufacturing is far from perfect. Thus in some regions, transistors are stronger than the nominal transistor, meaning that at a given voltage they conduct more current, while in other regions they are weaker and thus conduct less current. This causes two problems: Transistors that are located in the strong region will have a higher leakage current thus increasing the overall core power, while circuits in the weak region will have a problem meeting speed targets. The idea therefore is to diagnose the strength of the silicon, and to lower the voltage in strong silicon regions in order to decrease leakage currents while still meeting timing. The article does not disclose whether the silicon strength is determined by some sort of on-die sensors but simply states that the mechanism is based on embedded information.  I imagine that designing an on-die sensor to accurately determine transistor strength could be quite challenging, but not impossible. Whether such a design would be cost effective in the end is of course another matter. The article also describes voltage scaling based on temperature and has several charts to explain the details mentioned above and is definitely worth a quick glance.

The other day Microchip, a major provider of microcontrollers and analog semiconductors, launched ICwiki, a web-site it hopes will enable engineers to share best known practices as well as collaborate on projects. The site is currently available in several languages, allows for public and private discussions, and as the name implies it is based on Wiki technology. As stated in the press release, Microchip sees ICwiki as an extension to the University of Microchip, and at the same time as a foray into the world of social networking, hoping to capitalize on the recent social networking trend. In its current from though, ICwiki leaves much to be desired. The first missteps can be found in the registration process, where one has to complete more than fifteen fields to finally register. Compare that to Wikipedia which requires about five. It is understandable that Microchip would like to know who ICwiki users are, but that information should be collected on a profile page or something along these lines. Another major problem with the current implementation is that search function seems to be non-functional. The current system of browsing by topic and category, date or keyword will work, but will not scale at all once the number of entries increases. The content editor is minimal in functionality at best and the layout and overall look of the site needs improvement regarding ease of use and readability. Not to mention that on several occasions the site returned errors upon which it conveniently decided to go ahead to close the browser window – very annoying. The whole social networking aspect seems also to be missing, since other than sending email to other users there is not really a way of building a network. Other than the implementation problems, one has to ask the questions whether engineers will be willing to share best know practices in a public setting. Given how strict most companies are on disclosing any intellectual property outside of the company network, it is hard to believe that many professionals are going to feel comfortable discussing in-depth technical matters or best known methods. The exact purpose of having private discussions is also questionable, since people working on projects are likely to already have an internal system that they utilize for project tracking and discussion. Thus it seems that most likely ICwiki is going evolve into more of a discussion forum for specific questions regarding problems directly related to Microchip products, than anything else, at least in its current implementation. Regardless of the final outcome, Microchip should have waited with the announcement and done some more testing or at least a beta phase, since at the moment ICwiki does not seem production ready.

In a previous post I mentioned Semi Trends as a nice semiconductor news site to catch up on semiconductor industry happenings. It was simple, easy to navigate, and updated more or less on a regular basis. Well, compared to SemiTrends, eeNewsFeed.com feels like a two hundred pound gorilla. Don’t expect any personal commentary on this site. The first impression will tell you immediately that this site is all about industry news aggregation, with the home page brimming with article snippets to the point where it feels utterly cluttered and unreadable. But this site’s strength is not the home page but what lies beyond it. The main navigation menu is broken down into categories that seasoned designers will easily recognize. One thing that visitors might find handy is the company profiles section, which allows alphabetical and industry based searches for companies of interest. The search returns a brief description of the company as well as any feeds that are directly linked to this company. Alternatively, one can search general news for a subject of interest, and the search will return articles that contain the query as well as the feed from which the article came.

As implied by the name, feeds and feed management are what eeNewsFeed is all about. As show on the right, once you sign up for a free account, you can generate watchlists which can be organized as individual folders. These folders can then be assigned feeds of interest, which can either be company related feeds, feeds pertaining to specific articles, or feeds based on search criteria. For example, many companies have feeds for press releases or new product announcements which you can add to your watchlist. eeNewsFeed also features aggregate feeds that combine several feeds for a company into one. These feeds are company specific and will only contain items directly related to that company. On the other hand, feeds from articles that matched your query are generally feeds from a specific new source, such as EETimes.com. Obviously these feeds will contain a variety of articles on topics that may or may not be of interest to the reader. Feeds can also be created based entirely on your search query. Thus any article that matches your query in the future will show up in this feed. Each folder, or watchlist, can be configured individually to send you email alerts either on a regular schedule or when new articles become available.

While all of the functionality is relatively simple to setup and quite intuitive, whether it is actually better than feed management that can be found either through browser extensions or other online feeds management sites is  questionable. Still, the strength of this site lies in the fact that it is entirely focused on electronics engineering, and thus search results and the related feeds are likely to be far more relevant than what one would obtain by using one of the generic search engines. One area that the site could surely improve on is search speed. While the results are delivered in a reasonable time, the response is significantly slower than regular search engines. Overall though, if you need your daily dose of semiconductor news, and you want to customize it to fit your criteria, eeNewsFeed is hard to beat.