EVE Has released an enhanced design debugging capabilities for its ZeBu emulation platform. This capability uses a feature called Combinational Signal Access (CSA). It allows a ZeBu system to generate complete waveforms of the design. EVE aims to enhance productivity and lower the development costs.

The announcement comes even after Mentor Graphics Corporation initiated legal proceedings against EVE in the Japanese Court System on patent infringement allegations regarding the methods used in retrieving internal FPGA contents similar to the CSA mechanism announced. I have requested comments from Mentor but the company has chosen not to respond to my inquiries, at least not as to the date of this article. What I have been able to find out researching the topic of "read back methods and mechanisms" in FPGA is that the Xilinx Virtex5 components used in the ZeBu product provided a standard method for read back. There is nothing special that EVE had to implement to enable such feature, they just had to decide to use it.

The news that Mentor had filed and import suspension application with the Japanese Custom office against EVE broke on July 20 of last year. The news that the Japanese Custom Office had denied such application broke on December 16th of 2010. In spite of the results, I am told that the legal battle between Mentor and EVE is on-going and that, in the now usual style of the EDA industry, both companies are spending on lawyers fees what instead they should spend in R&D.

Of course Mentor has the right to protect what they believe is an asset, but I find it strange that it is not straightforward for their corporate communication department to mention the patent number and description of what allegedly EVE is infringing in response to my query. What follows is the complete text of the corporate press release issued by Mentor on December 16, 2010.

Mentor Graphics Corporation (NASDAQ: MENT) today announced it will continue its claims of patent infringement against EVE emulation products in Japan before the Tokyo District Court in accordance with the ruling from the Japanese Customs Office.
"The Japanese Customs office found that there was insufficient, publically available evidence to rule for us in our request for an import ban on EVE’s emulation products," said Tom Evans, corporate intellectual property counsel for Mentor Graphics. "A majority of the appointed experts did not challenge the broad scope of our patent, and further suggested that this case be examined at a civil trial. For example, one expert noted, "[in] general, cases such as this case - where the establishment of the evidence…of the undisclosed techniques on the part of the suspect accused of the infringement is required - should be tried using the procedures for the action for infringement…in accordance with the Patent Act or Code of Civil Procedure."

EVE claims that using CSA, values of any register transfer level (RTL) net, register, or memory in the design are available quickly with unlimited trace depth and without embedding instrumentation or recompiling the design. As Lauro Rizzatti, general manager of EVE-USA states: "With CSA, tracing a design bug in large designs of hundreds of millions of ASIC-equivalent gates is no longer a tedious, uncertain and, ultimately, ineffective exercise. Early users of this new ZeBu capability confirmed that design bugs can be pinpointed in just a few hours, if not minutes, on the largest designs."

The ZeBu functional architecture with the new feature highlighted in green.

CSA uses the readback circuitry that is standard in the Xilinx FPGAs used in the ZeBu emulator and works in one of two modes. Either on-line, when waveforms are generated while the model is running on the emulator; or off-line, when waveforms are generated after the emulation run, enabling the emulator to be used for other applications. The off-line waveform generation process can be done on the user’s computer and accelerated for very large designs through a proprietary multicore technology.

The CSA feature comes as a standard component to the ZeBu family. It is available now and, initially, works with zFast, ZeBu Fast Synthesis used with ZeBu emulation systems.