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Pumping Up Precision
Mentor Upgrades Synthesis
Perhaps the most under-appreciated technologies in the FPGA design flow are logic synthesis and physical layout. Most of us download the vendors’ tools, grab some IP, whip up a little RTL, push the button, and wait around for our timing report to say “Pass”. After all, that’s the easiest thing to do, and following the path of least resistance is highly attractive when so many tasks on the critical path of our project are prohibitively difficult.
We have basically no choice on layout tools. Unlike in the ASIC world, we can use only the layout tools provided by the FPGA vendor we select. Synthesis, however, is another story. There is a wide variety of synthesis tools available, and your choice of synthesis tool (along with your level of expertise using it) is probably one of the most important factors in the ultimate performance of your design. Synthesis technology varies widely in terms of quality of results (QoR), and those results affect everything from your design performance to power consumption to the size and cost of the FPGA device required to implement your design.
While FPGA vendors’ tools have improved significantly in recent years, one has to ask– “Does my FPGA vendor care if my design gets squeezed into the smallest, cheapest, lowest-speed-grade part?” Probably not. It might actually be to their advantage if you ended up with a larger or faster (read – more expensive) part than you might have otherwise required, as long as you never knew the difference. The people making third-party synthesis tools, however, have extreme motivation to give you top-notch quality of results.
Any third-party supplier of FPGA synthesis tools faces a tough challenge. FPGA vendors give away competing products essentially for free if you’re buying their silicon. Selling third-party FPGA synthesis tools is like selling aftermarket wheels for new cars that already come with good ones. In order for EDA companies marketing competing third-party tools to make any money, they have to demonstrate compelling value in order to win you over from the free tools already included in your design kit.
Luckily, they typically do.
The basic value proposition always boils down to two basic elements – quality of results and vendor independence. In reality, either of these arguments should be sufficient. If your project is doing any volume at all or has any sensitivity to time-to-market, BOM cost, or performance on the FPGA component, you’re silly not to give careful attention to third-party synthesis tools. [more]
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