Santa Cruz, Calif. In the 1990s, Elliot Mednick pioneered low-cost Verilog simulation. Now he's made his VeriWell simulator a free, open-source offering available through the Sourceforge Web site.
"I'm not doing this for my personal gain," said Mednick, who today is a principal engineer at behavioral synthesis provider Bluespec Inc. "I just think people will find it useful, so why hold on to it?"
Once a product sold by Mednick's previous company, Wellspring Solutions, from 1992 to 1998, VeriWell today is an IEEE 1364-1995-compliant Verilog simulator. In between, Mednick sold Wellspring to Minc, shortly before that company went out of business. Xilinx then purchased the assets of Minc, including VeriWell.
"I don't know what Xilinx had in mind for VeriWell, but at some point I asked for it back," Mednick said. "They said that so long as they could keep a perpetual license, I could get the rights back." That was around 2000, Mednick recalled.
Instead of selling VeriWell, Mednick decided to make it an open-source product. But he didn't follow through until recently, he said, when he realized that people are still using the simulator. So he got together with a former partner, cleaned up the code and put it up on Sourceforge under the GNU public license.
Mednick said that he started to think about open source in 1991, when VeriWell was conceived. Richard Stallman, the founder of the Free Software Foundation, tried to convince Mednick to make it an open-source product at that time, but Mednick didn't see how he could make any money with it.
Wellspring sold several hundred copies of VeriWell at prices ranging from $995 to $3,500. "It was enough for me to make a living and have some employees for several years," Mednick said, "before sales slumped and I got tired of doing it."
The irony, perhaps, is that the free version of VeriWell was far more successful. This version was included with several popular textbooks and was available for free download. Perhaps 10,000 copies were distributed, Mednick said.
Today, VeriWell is dated, given that it does not comply with the more recent IEEE 1364-2001 standard, let alone the 2005 update released this year. But this interpreted simulator is fast and extremely easy to use, Mednick said. In a recent edition of the E-mail Synopsys Users Group, Mednick said he ran some benchmarks and found VeriWell to be four times faster than Icarus, a well-known open-source Verilog simulator.
Not that Mednick is trying to compete with Icarus, which he acknowledges has "way more features than VeriWell." With two free simulators, he said, there's no reason not to try them both.
Mednick is now hoping that a community will emerge to help take VeriWell to the next level. It could use 2001 and 2005 extensions, some bug cleaning and a virtual programming interface, Mednick said.
VeriWell is available for download at https://sourceforge.net/projects/veriwell. For support, you're on your own. Mednick, who was out of the EDA industry for a while, is focusing on his new job at Bluespec.
"I really love it," he said. "We have real products and big-name customers, and customers are starting to understand that the whole concept of behavioral synthesis is real."