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  • Billion Transistor Designs Need Faster Full Chip Tools

    During the design cycle as tape out approaches, time pressure usually goes up dramatically. To make matters worse the design itself is much larger, because all the block level work is done and there is a requirement to work with the entire database. It feels like itís time to put aside the garden trowel and start using a steam shovel. This is when whole-chip DRCs are run and each change needs to be double checked to ensure that no inadvertent changes to the design have been introduced. At this stage, all the tools that were used to initially make the design are most likely sagging under the weight of the fully assembled and nearly finished database. Fortunately, there is an EDA vendor working specifically on solving these design challenges. The Taiwanese company AnaGlobe was founded in 2000 and has a solution for viewing, fixing and comparing the largest design files in existence.

    Article: Is the RTL Design Flow Broken?-fast-read.jpg

    I caught up recently with Ted Chou, AnaGlobeís Corporate Applications Engineer, to go over their Thunder Integration Platform and Thunder LVL tool. One of their most significant advantages is high capacity and extremely fast database read in and writing. They have their own database called Thunder DB, but can read GDS, LEF/DEF and OASIS. The Thunder DB is about one tenth the size of GDS. Their extremely fast read-in can read in a 17 GB database in around 8.5 minutes. Ted pointed out that other tools can take around 112 minutes for this size design. So, the time saved is significant. Similar gains are seen for database writing. He also pointed out that their performance scales well when additional processors are used.

    Their tools operate with the full design in memory, so no viewing or editing operations require disk file access. This makes Thunder a great choice for viewing and fixing DRC errors found with Calibre. AnaGlobe offers an integration with Calibre and ICV. But what appears to be one the most compelling motivation for using Thunder is its LVL capability. Unlike Calibre, no rule deck is needed for Thunder LVL. Another incentive is that you can use your Calibre license for something else when running Thunder LVL, and Thunder only needs one license to run on multiple CPUs, unlike Calibre.

    Article: Is the RTL Design Flow Broken?-anaglobe-lvl-summary.jpg

    Thunder LVL can run flat or hierarchical. Some of the runtimes that Ted shared with me were impressive. On a 170 GB design file with 393 layers, other tools took 15 hours with 12 CPUs. Thunder LVL ran in 1.7 hours. Thunder LVL also features synchronized viewports for viewing differences in the design that it reports.

    There is a lot to say for companies that pick a niche and focus relentlessly on delivering a support product. It helps that the founders come from TSMC and Springsoft, both companies with excellent bona fides. From the looks of it AnaGlobe is enjoying good adoption rates at a number of the largest semiconductor companies. This makes sense because their market focus is on the largest designs. For more information on AnaGlobe and their Thunder products be sure to look at their website.

    In an interesting side note, I worked at Calma, the company that created Stream format. In fact, that was the name of their layout editor, GDS II. Yes, there was a GDS I before GDS II, but Stream format was a GDS II utility and was never used with GDS I. I had the opportunity to meet Sheila Brady, the woman that actually wrote the very first Stream import and export utilities. Just to give a frame of reference, this was back the in early 1980ís. Itís testament to some good software design that GDS Stream is still in use today. Of course, it has been adapted to handle todayís more complicated technologies with the addition of more layers and datatypes, and larger record sizes. However, even back then I remember her saying that she really only intended it just to be a tape archive format, not a database for design hand-off, etc.

    In one sense, itís amazing it is still in common use. But this also makes the case for using newer more efficient databases and formats for todayís design challenges. Imagine if you were still using any other technology from 1980 for your daily tasks: floppy disks, 100MHz processors, magnetic tape drives, dial up modemsÖ..