Top Gear: PADS Professional Road Test

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We hear all the hype about new EDA tools, but how do they actually perform on your design? This month, I road-test Mentor Graphics’ new PADS Professional and put it through a rigorous performance evaluation. Let’s see how the Xpedition technology actually performs when integrated into the PADS tool suite.

Opening the hood, we see an impressive line-up of features including signal and power integrity, thermal analysis and DRC support for traces violating split planes, reference plane changes and shielding. All the essentials for today’s complex high-speed designs! Plus, I am looking forward to trying the dynamic plane generation feature—regenerating copper pours is always a pain to perform, in any software. And of course, PADS Professional includes all the standard features one would expect in a high-end tool. 

Based on Xpedition technology, PADS Professional is a major improvement over the previous PADS suite of tools. I was first impressed by this technology in 1994, when I attended the VeriBest PCB training and the sales kick-off in Boulder, Colorado. During the sessions, a few of the Intergraph Electronics sales guys were taken out back, into R&D, and were shown the latest routing technology—eyes lit up with dollar signs as the VeriBest (now Xpedition) router was put through its paces.

Meanwhile back in Australia, where I was responsible for Intergraph Electronics sales and support, customers were also suitably impressed. My first sale was six seats of VeriBest PCB with 20 seats of Design Capture to Fujitsu Australia, who had previously used Cadence. Both Cadence and Mentor presented their flagship products (Allegro and Board Station, respectively), but the VeriBest router was so impressive that the competition did not rate mentioning. Ron Oates, CAD manager of Fujitsu Australia at that time, stated in a press release, “VeriBest is light years ahead of the competitors.” And it is still arguably the best routing technology available today. Mentor went on to acquire VeriBest in 1999, as the lack of routing technology formed a fairly large hole in their PCB offerings. Needless to say, Mentor’s stock rose 9% after the acquisition was announced.

I won’t bore you with a full list of functionality or standard EDA tool features, but rather I will take you through, in detail, what I see as the outstanding features of PADS Professional.

PADS Professional utilizes xDX Designer as the front-end design entry tool. This schematic capture package was originally a ViewLogic Systems tools called ViewDraw, which became the unified front-end tool for all Mentor PCB products some years ago following an acquisition. Originally developed for creating hardware description language (HDL) function blocks for digital and mixed-signal systems, such as FPGAs and ASICs, it has a multitude of interfaces and is adaptable to many environments. In the PADS environment, it interfaces to the PCB (of course) but also allows FPGA I/O optimization, the integration of library tools, DxDatabook, and downstream digital and analog (EZWave) simulation tools.

But as far as I am concerned, the ability to launch HyperLynx LineSim at the schematic level is its best attribute. After selecting a net, the LineSim link loads the data from xDX Designer and exports it to HyperLynx to create a pre-layout free-form schematic view of the nets topology as in Figure 2. You can then simulate a sample of nets for, say, data, address, clocks and strobes to define the layout design rules. These rules are embedded in the schematic via the constraints manager, and they will then flow through to the layout database with forward annotation. Constraints are maintained through a common database that is consistent and in an easy-to-use spreadsheet interface. There is no need to learn an obscure program language to create complex constraints as in other tools.

To read this entire article, which appeared in the September 2015 issue of The PCB Design Magazine, click here.


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