Guest Blog by Imec: De-risking Technology Choice
Thank you to Dr Paul Zuber for this contribution to Sondrel's Blog. Paul is a System Architect, and manages imec IC-Links IP and design partner program.
In our team at imec IC-Link we have developed a web-based instrument that allows our partners and customers to compare technology options prior to design. We call it “de-risking technology choice” because you will not get a chance to revise a wrong technology choice later in the product development process. Or if you do, it will be expensive. In addition, startups and even R&D departments of larger companies are drowning in a flood of new technology options.
Typical customer questions include
- ‘what is the difference between a high performance option and a mobile option in 28nm?’
- ‘what about that option plus recently added?’
Whilst these questions are typical for newer nodes with multiple options and PVT points, it is also true for older nodes. The foundries still actively develop these by means of new process options, tweaks or updates.
- ‘Is 65 or 55 the right node for my circuit?’
- ‘What performance difference does the CMOS imaging option make in 180?’
The last two examples relate to our most popular choices, which is in line with many independent observers in the field. In addition, generic questions such as
- ‘Should we use more gate-length offset or higher VT’ or
- ‘Is there a temperature inversion at lower VDD for my technology option?’ are occurring every day.
Addressing these questions is crucial but can be cumbersome when done the traditional way, such as flipping through excessive amounts of pdf files or setting up and running lengthy synthesis runs for a few test designs and technologies.
- Rigorously tested technology access routines, accumulated over 35 years joint experience in the field
- Solid JAVA API backend implementation
- Uses original foundry data
- Multiple security features
- Free access by partners and customers
The core of this computer code is based upon 35 years of joint experience in the field, and tested against thousands of libraries and dozens of designs. Although the APIs are accessible through any kind of scripting framework or standalone application, we decided to develop a web-based front-end for easier adoption by engineers and business developers. As a result, the three most common applications are now accessible through our web tool.
Thanks to a public format of the industry standard Liberty, it was possible to create an API to access timing, power and other properties of any standard cell in any technology library, through a simple function call. This turns out to be very practical, as one can generate multiple values for multiple cells within the same library or for corresponding cells from different libraries within one session, in order to understand their differences. The three web applications all make use of our Liberty Access Toolbox, replacing the need for coding by a web-based graphical front end.
Imagine an interactive data book, with no more pdf file searching, manual number interpolation or unit conversion. Imagine a simple as-you-type search with instant suggestion for library choices and cell choices matching the features you entered. Select an entry, and a second or a third, and you see an ordered overview of the cells’ PPA values. To ensure comparability, we apply well-defined input and output conditions of every cell automatically.
Similar in usage and concept, this tool scatter-plots entire libraries in a chart, each cell becoming a dot, with a different colour for each library. This is great to compare overall library trends. It is possible to assign different metrics to the axes and to filter by cells names to see only a few important cells.
The use of this application adds the design as a parameter, and thus exceeds the possibilities of technology data books, which perhaps consider ring oscillators as the most complex input. It enables PPA predictions of a (or several) given critical path(s) as a function of the library. The operation is based on a re-mapping of the cells, and a re-evaluation of its timing. Since all effects of non-linear delay models and timing rules are respected, the timing path results are within 1% of digital design tools. Remapping to a different PVT point or technology flavor within the same node does not change this accuracy. When going across 1 or more technology nodes, the accuracy decreases, but is still sufficient to get a first estimate with very little effort.
For more involved analyses, the Liberty Access Toolbox is also deployed in custom projects. We used it to co-explore design and technology choices, express technology merits in custom metrics, automate option analysis, shipped it as custom tools, did variability analysis, and more. We also used it in conjunction with our Spice and GDS Toolboxes for even more custom analysis.
In summary, in imec IC-link’s technology selection program, we help partners de-risk technology selection. A growing number of customers and partners are now making use of the three complementary web tools to manage the flood of new technology choices and sketch first solution paths for their next generation design:
- Cell Analysis – interactive data book
- Library Analysis – high-level library comparison
- Design Analysis – update critical path timing under new library
We are driven by saving time for technology evaluation by providing useful and correct results and ease of deployment. No installation is required, and the webtools are freely accessible by partners and customers.
Imec IC-link is the semiconductor manufacturing division of imec. They help innovators, entrepreneurs and universities realise their ideas in silicon by providing low-cost prototyping, volume production and system integration of electronic assemblies.
This webtool has been developed to assist customers and partners of imec. For more information you can contact Paul Zuber, firstname.lastname@example.org
Sondrel is an international design partner of Imec IC-link. Imec IC-link has formed local and international partnerships with leading design houses and IP providers. These long-term, trusted relationships allow our customers to have access to wider range of services and products.
Contact Sondrel to explore the design support options that we can provide for your SoC Projects.