El SkyWater 130nm PDK is an open CMOS process design kit that has revolutionized access to integrated circuit manufacturing. Thanks to the collaboration between Google and SkyWater, designers can now explore and manufacture their own chips without the need for expensive licenses. In this article, we explain Everything you need to know about SkyWater PDK, from installation to supported tools and best practices.
Being a open source projectSkyWater PDK offers the design community the ability to experiment and improve their designs with accessible software and hardware tools. Although not yet ready for mass production, this kit represents a unique opportunity for the development and validation of new integrated circuit designs.
What is SkyWater PDK?
SkyWater PDK is a process design kit (PDK) based on SkyWater Technology Foundry's 130nm technology. It was launched as an open source project with the aim of democratising access to integrated circuit design.
While this PDK is not currently geared towards mass production, it is ideal for Design validation and the creation of test chips. Google and SkyWater continue with internal testing and in-silicon validation of the released data.
Tools compatible with SkyWater PDK
One of the most interesting aspects of SkyWater PDK is the support for multiple design and simulation tools. Some of the most prominent are:
- Magic: An integrated circuit design software that allows the creation of layouts, although its use can be laborious due to its manual interface.
- OpenLane: An automated design flow based on open source tools that facilitates the placement and routing of standard cells.
- Qflow: An automatic design toolset that enables integration of SkyWater 130nm, although its compatibility is partial.
- ngspice and Cadence Spectre: Two widely used simulators for the circuit verification.
While some tools like OpenLane facilitate the design process, integration with SkyWater PDK may require additional work and custom adjustments.
SkyWater PDK Architecture and Blocks
SkyWater PDK includes different design blocks that facilitate the creation of custom circuits:
- I/O cells: A collection of cells and primitives that allow input and output rings to be built.
- Input and output buffers: With different consumption capacities and configuration modes.
- Reference generator: Used to provide reference voltages to some PDK blocks.
Challenges and considerations in using the SkyWater PDK
Although SkyWater PDK is a powerful tool, it has certain Limitations and challenges to consider:
- Learning curve: Some tools require advanced knowledge in circuit design.
- Limitations in production: Currently it is not oriented towards mass manufacturing, but towards validation and testing.
- Availability of documentation:Despite being an open initiative, some technical aspects may lack detailed documentation.
However, the open source community has implemented several improvements and generated additional resources to facilitate the use of the PDK. The SkyWater PDK has become a key reference for experimentation and development of new integrated circuit designs. Despite its challenges, it offers a unique opportunity for designers and researchers to work with advanced tools without intellectual property restrictions.