Magma to try to take on Virtuoso
Magma Design Automation has decided to try to take on the hegemony of Cadence Design Systems in mixed-signal design. Cadence currently holds a commanding share of the market for analogue and custom layout through its Virtuoso tool. But, in recent years, a growing number of design-tool vendors have decided to try to chip away at that lead.
Magma has chosen to concentrate on users who are using a mixture of standard-cell digital, custom-digital and analogue circuitry on leading-edge processes rather than customers who devote a large part of their chip designs to analogue or radio-frequency blocks. “Analogue design on the advanced process nodes is similar to what we see being done on the digital side,” said Ashutosh Mauskar, vice president of product and business development manager at Magma.
Some parts of the Titan portfolio that Magma has put together already exist: principally the FineSim analogue-circuit simulator. Alongside that, the company has launched its own layout editor, which Mauskar said is able to deal with large chip designs better than Virtuoso and will read and write to an OpenAccess database: the same format as that used by the latest major release of Virtuoso. But Mauskar conceded that Cadence continues to have an effective lock-in with the way Virtuoso handles automatically generated macros or P-cells. These are written in Cadence’s proprietary Skill language.
Magma has decided to embrace the format put forward by the Interoperable P-cell Library (IPL) group, which defines macros that can be generated by standard languages such as Python or Tcl. Magma’s layout editor will import Pycells written in Python although its native scripting language is Tcl as that allows control over the graphical user interface as well. In terms of support for Cadence P-cells, Mauskar said the main option today is to use a third-party interpreter such as the one written by Ciranova. But he pointed out: “Migration of P-cells used to be intractable. Now it is possible.”
The technique that Magma hopes will convince Virtuoso users to cross over to Titan is constraint-driven design. The idea is that engineers define circuit parameters as mathematical expressions and then use tools to generate layouts from those representations that fit a range of different processes. Potentially, it will also allow designers to explore a wider range of architectures when trying to fit an analogue function to a process, Mauskar claimed. “Because they are doing the design largely by hand today, they don’t have the time to explore different architecture,” he said. “For any single given constraint, a human can do a better job. But humans can only produce one implementation in the time that a machine can generate multiple candidates from a set of constraints.”
Mauskar said this form of automation will become more important as system-on-chip (SoC) designers migrate analogue circuits to each advanced process as it appears. Although there are no standards for constraints languages at the moment, Mauskar said Magma would follow the IPL if it decides to pick one. He said Magma may offer its own language as a candidate. “We are working very closely with the consortium,” he added. “We are open to donating our language: that is not an issue.”
As well as the layout editor, the company has developed a shape-based ‘finishing’ router intended to tie together standard-cell and custom-layout blocks.
Image: Magma is introducing its own layout editor as part of a plan to tempt Cadence users over to its mixed-signal design toolsuite