Electronic Design

Latest EDA Tools Reveal Analog Design's Changing World

There is indeed a shortage of analog designers. But it's less a shortage of circuit wizards like Bob Pease than a dearth of well-seasoned engineers who could create user-friendly mixed-signal designs on a piece of silicon.

The underlying need is for increased industry-university outreach to engineering undergrads. In the meantime, the EDA community is hard at work making mixed-signal chip design easier. For example, Cadence Design Systems recently updated its Virtuoso custom design platform, adding an advanced "XL" level to its basic "L" level.

The new tool addresses a range of process nodes and design styles, from 180-nm analog and up to 45-nm digital and down, including system-in-a-package (SiP) or mixed signal at 130 nm, mixed signal at 90 nm, and RF system-on-a-chip (SoC) at 65 nm.

This keeps Virtuoso contemporary with current process technologies. But it's noteworthy that Cadence also put a lot of effort into making the tool easier to learn and use. For instance, the new version of the Virtuoso schematic editor adds assistants to simplify searching, property editing, viewing, and traversing the design hierarchy. Other new capabilities include tabs and configurable workspaces.

At the GUI level, new menu structures mirror common features in Web browsers. Now, commands can be executed using user-programmable bind keys and object-sensitive pop-up menus that display relevant operations for objects under the cursor, anticipate user requirements, and present only pertinent choices.

Cadence also combines specification entry and design management into a single unified cockpit. A "specification" consists of multiple tests, which are formed by combining test harnesses with specific measurements. Once created, the tests and the complete specifications can be shared and managed across multiple design groups.

Meanwhile, a "project level" provides access to all the tests, sweeps, corners, scripts, and documentation. At any time in the design and verification process, any circuit can be monitored against its objective specifications with pass/fail feedback. Another thoughtful feature is that all sweeps, corners, Monte Carlo statistics, and measurements are managed and stored in one location.

Beyond the L version's basic polygon layout editing features, XL's custom-block authoring physical-layout tool supports constraint-driven and schematic-driven physical implementation of designs at the device, cell, and block levels.

"Constraint-driven" means designers can incorporate constraints in a schematic to ensure their design intent is captured and considered downstream, while manufacturing constraints also can be incorporated upstream in the design phase. Other new features provide advanced connectivity and constraint-driven and design-rule-driven functionality.

What Cadence has done at the analog chip design level parallels what analog chip makers have done at the circuit level, but much of the opportunity for artistry still remains. Analog design is still far from becoming a mere turn-the-crank process.

"Custom design is all about mixing technical know-how with artisan craftsmanship to achieve your final goal. Custom design does not come out of a book. It comes out of an innate intuitiveness that separates the great engineer from a good one," said Steven Lewis, Virtuoso's product marketing director.

"Much like the trades of years past, analog design is one of the master engineer teaching the apprentice how to be a journeyman, and that journeyman becoming a master in his own right by doing actual designs and seeing how they work, how they don't work, and most importantly, how to finesse them back into working again," he continued.

"This is a business where you not only don't check your brain at the door, you better be bringing both halves if you want to be able to call yourself an analog designer."

Cadence Design Systems

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TAGS: Components
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