Mentor Offers Platform for AMS, Cell Developers

Mentor Graphics has augmented the IC Station tool suite with the release of Pyxis, a custom router, cockpit, and data-interchange tool for analog, mixed-signal, and digital cell designs. The platform, optimized for AMS and cell designers, gathers data management, design entry, simulation control, visualization, and layout editing tools.

At its heart, Pyxis includes the custom router for which the platform is named: the highly regarded hierarchical custom router Mentor acquired with its purchase of Pyxis Technology. Mentor claims for the new router digital-router speed, and the ability to propagate constraints through the design from transistor to cell, block, and full-chip levels.

The ability to move between levels can be vital, according to Tom Daspit, Mentor product line manager. In designs such as an integrated camera SOC, where there are digital cells, analog circuits, and a large sensor array that blocks routing, the ability to move quickly between levels of hierarchy can be vital, Daspit explained.

Further, Daspit pointed to Pyxis' facility with designs that require large numbers of power domains. Taken together, Mentor said, these capabilities allow fast iterative layout and analysis of AMS designs and digital cells, allowing a degree of exploration within a DRC-clean envelope that was hitherto impractical.

Another platform feature aimed at productivity is concurrent access, including concurrent access by multiple engineers to the same cell. Pyxis allows multiple designers to define non-overlapping fences, and to work concurrently, each designer within his or her own fence. In this mode, designers have the ability to mark up a shared view of the design on a virtual whiteboard, and to message within the environment. This feature should allow large AMS designs or cell-library efforts to be partitioned across a global design team, reducing schedules and turn-around on ECOs.

That is, it should work if access/revision control and human management are up to the task. This is an interesting reservation because dependency analysis, fundamental to revision control, is a non-trivial exercise in large AMS designs. Often analog links such as capacitive coupling are visible only at more detailed levels of abstraction, and so designers working at higher levels may be unaware that they have made changes that will influence areas outside their fence. "Some analog design teams will put these links in explicitly in the schematics, and that can make recognizing dependencies simpler," Daspit said. "That is not something that digital designers typically do today."

Of equal interest is the close integration between Pyxis and Mentor's other heavyweight tools, the Eldo and Questa simulators and the Calibre physical-design system. In particular, Pyxis can invoke a Calibre Realtime run to provide dynamic, as-you-go DRC on an evolving layout. There is also a link to the Calibre 2.5D extraction tool. And while Mentor continues to use its own proprietary design database, Pyxis can exchange data with an OpenAccess database through import/export utilities.

Mentor Graphics