MOUNTAIN VIEW, Calif. — Synopsys Inc. is making a complete, front-end ASIC design flow available under Linux. The company this week will announce the availability of Design Compiler and other popular chip design tools for the open-source operating system, a move that opens the door for the widespread adoption of Linux as the No. 2 EDA platform and very possibly writes the epitaph for Windows NT in chip design.

Synopsys is porting virtually all its front-end tools to Linux, including Behavioral Compiler, Design Compiler, Module Compiler, FPGA Compiler, PrimeTime, TetraMax and the Scirocco VHDL simulator. Synopsys' VCS Verilog simulator was already there. About all that's missing from the current list is Physical Compiler and the Epic physical verification tools.

"We think Linux is ready for EDA and EDA is ready for Linux, and we will go and make that market," said Raul Camposano, chief technology officer at the Mountain View company. Camposano said Synopsys believe Linux could claim 10 to 20 percent of Synopsys' revenues within the next two years. He expects that the rest will be Unix, with Windows NT strong only in FPGA design.

Camposano made it clear that Synopsys views Linux, not Windows NT, as the emerging No. 2 platform for chip design. "With the exception of FPGAs we have seen very, very little market adoption [of NT]," he said.

This attitude marks a sea change from two years ago, when a handful of vocal advocates were clamoring for Linux and EDA vendors were claiming there was no real demand. Analysts didn't include Linux anywhere in their forecasts.

Since then, however, a number of simulation tools have added Linux support, because users want to construct large simulation "farms" populated with low-cost PC platforms. Synopsys this week will become the first major EDA vendor to take Linux significantly beyond simulation and to provide a complete front-end design flow.

"Basically, Linux is knocking NT out of the design world," said Gary Smith, chief EDA analyst at Dataquest Inc. (San Jose, Calif.). Preliminary Dataquest figures show a potential 25 percent growth in Linux revenues for front-end chip design in 2000, 50 percent in 2001 and 70 percent annually for the following three years.

Smith thinks Linux will move more slowly into the pc-board market, and even slower into IC layout, which needs 64-bit processing and workstations with more memory than today's PCs pack. And 64-bit Linux isn't yet available, he noted.

The Synopsys announcement, Smith said, "has taken away the last stumbling block. Now that Synopsys is out there with the whole tool set, there's no reason not to use [Linux]."

Interest in Linux

Other EDA vendors are seeing keen interest in Linux. "I think Linux will replace interest in Windows NT and complement the Unix environment, but it won't replace the Unix environment," said Mike Glenn, head of corporate product management at Avanti Corp. His company offers the Polaris Verilog simulator, Nova-Explore RTL design analysis tool and Hercules physical verification tool under Linux.

Rahul Razdan, corporate vice president at Cadence Design Systems Inc., said his company is seeing more demand for Linux than for Windows NT outside of the FPGA marketplace, where NT remains strong. Cadence's simulation tools, including the widely used NC-Verilog and Verilog-XL simulators, run under Linux.

Mentor Graphics Corp. offers its ModelSim simulator, IC Station tool suite and Calibre physical verification tool suite under Linux.

Graphics-chip provider Nvidia Corp. has a 400-machine Linux farm running VCS simulations, said Chris Malachowsky, vice president of engineering at Nvidia. He said his company looked at NT, but found it "too foreign" to adopt.

"No one even knew where to open up an editor," he recalled. "The beauty of Linux is that it looks just like our Unix desktops. It just feels so familiar."

Synopsys' Camposano said that demand for Linux EDA support has soared during the past two years. In a Synopsys customer survey, 2.6 percent of respondents said Linux was their first or second most widely used workstation platform in 1999. But more than 37 percent expect Linux to be their first- or second-choice EDA platform by 2002.

One thing that's changed, Camposano said, is that Linux has become clearly established in the server domain. Another change is that the open-source model has become more acceptable to large corporations. Finally, Linux has become attractive because of its compatibility with Unix, and because of the much-acclaimed stability of the operating system.

For EDA vendors, Camposano noted, support has become much easier now that Red Hat Software is providing some standardization of Linux. Synopsys products will be available on Red Hat version 6.2 in the first quarter of 2001. Porting is also fairly easy, he said, because Linux is essentially just another version of Unix.

On the farm

Dataquest's Smith pointed out that Linux provides compatibility with Unix testbenches, scripts and shells. "You'd have to rewrite all that to move to Windows NT, and you'd have to take your best engineers off design products to rebuild their design environment," he said.

While Linux's popularity in simulation server farms is well established, its future in synthesis is not yet known. "It's probably too early to quantify it, but we've had interest from many, many customers who have asked for synthesis under Linux," said Camposano.

Cadence's Razdan, however, said his company had only seen "a little bit" of interest in synthesis under Linux. He said Cadence's Ambit synthesis products have already been ported, but Cadence is waiting for Linux synthesis to become more viable from a business point of view.

"Where we see [Linux] demand right now is in situations where a lot of parallel activity is needed," Razdan said. "You don't typically run a lot of parallel jobs in synthesis or physical layout." For such applications, he noted, Sun workstations still hold an edge in memory and disk capacity.

Avanti has seen some interest in Linux synthesis, but its Jupiter synthesis product is new and will stay on Unix platforms for now, Glenn said. He also said there's some interest in IC placement and routing under Linux. Avanti is considering such a move, probably through a strategic partnership, he added.

Camposano said Synopsys will port Physical Compiler and the Epic physical analysis tools to Linux "as the market demands."

Nvidia's Malachowsky said he welcomes Linux-based synthesis, because until now, he's had to bounce back and forth between Linux for simulation and Solaris Unix for synthesis. But he doesn't yet know if there will be much of a price/performance advantage to running synthesis on PC platforms under Linux.

"The advantage [of Linux] is that the fastest Sun desktop machine I can get is 400 MHz, while I can get 1.2-GHz PCs," he said. "The difficulty is large memory models. People haven't been building cheap PCs with lots of memory. There's a bit of a learning curve right now to find the configurations of hardware and software that will allow big memory jobs."

Malachowsky doesn't yet anticipate using Linux for IC physical layout, because of both memory and stability issues. "I know my Suns will run for nine months at a stretch," he said. "I don't have the same confidence yet in Linux platforms."

Mentor Graphics sees Linux as primarily a tool for batch-oriented jobs like simulation or design-rule checking, said Anne Sanquini, vice president and general manager of Mentor's HDL design division. "Customers still prefer NT, Solaris or HP/UX on their interactive desktop," she said.

It is unknown whether Linux will have much impact in FPGA or pc-board design, areas where Windows NT is strong. Dataquest's Smith thinks the FPGA world will go to Linux. The pc-board world is less clear, "but my guess is they will switch," he said.

Camposano acknowledged that Linux today appeals more to "mainstream" than to "power" users. One reason, he said, is that Linux now supports only four processors. However, "I think the problems of moving to the high end, and supporting more memory and more processors, are being solved by the Linux community," he said. "I think the operating system will be as mainstream in EDA as it is right now in other applications, such as networking."