Layout Database File Control: The Missing Link


By Dr Philippe Morey-Chaisemartin & Frederic Brault XYALIS, France. As the exchange of layout descriptions between teams involved in modern integrated circuit (IC) development and production increase in terms of rate, value and size, the need for control and reliability …

Is it time to switch to OASIS.MASK ?


By Dr Philippe Morey-Chaisemartin & Frederic Brault XYALIS, France. A summary of OASIS ® standard advantages and weaknesses is presented, based on six years of experience with customer databases. A new standard, OASIS.MASK, is being introduced to address the requirements specific to …

Highlights of XYALIS tools in Kalray design flow


Context Kalray, a French startup has developed an advanced array processor including 256 cores. This chip has been designed using TSMC 28nm process. Combining huge designs with complex process rules as lead to a bottleneck regarding layout finishing. Typically, dummies …



It’s a banality to say that nowadays, databases for digital chips are more than huge. The physical description of an SOC, encoded in the classical GDSII format, now often goes over 20Gbytes. Files of up to 200Gbytes have been reported by mask houses.

Even if storage systems and data transfer links can handle such sizes, it is obvious that so big files are difficult to manipulate.

GDSII was introduced by Calma in 1978 as a successor of GDS format created in 1971. Since almost 30 years, no major change have been made to this de-facto standard while chips complexity was multiplied by 105 to 106.
In addition to file size issue, numerical values needed to describe geometries of nanoscale structures on 300mm wafers will soon reach the 32 bits limits of GDSII format.

With concerns to such problems, OASIS format was developed and its first official specification was released in 2004 [1].

This article, shortly describes how size and precision limitation issues are managed in OASIS format. It also point out some critical points of this format and finally gives some tricks to really get full benefits from OASIS.
This article is based on the extensive experience of Xyalis on GDSII manipulation software and will show how to use its new OASIS capabilities to circumvent potential pitfall and problem using this new standard.