Known Issues¶
This section of the documentation provides a list of currently known issues in the currently released files.
See also the SkyWater PDK GitHub issue list to see the latest reported issues.
Warning
Google and SkyWater are currently treating the current content as an experimental preview / alpha release.
While the SKY130 process node and the PDK from which this open source release was derived have been used to create many designs that have been successfully manufactured commercially in significant quantities, the open source PDK is not intended to be used for production settings at this current time. It should be usable for doing test chips and initial design verification (but this is not guaranteed).
Google, SkyWater and our partners are currently doing internal validation and test designs, including silicon validation or the released data and plan to publish these results.
The PDK will be tagged with a production version when ready to do production design, see the “Versioning Information” section for a full description of the version numbering scheme.
To get notified about future new releases of the PDK, and other important news, please sign up on the skywater-pdk-announce mailing list [join link].
Documentation¶
A number of sections in the documentation still have pending TODO items. These will be fixed over the coming months.
The current cell datasheets only include basic information about the cell. These datasheets will be continuously updated with new information as the generator is improved.
PDK Contents Issues¶
Tooling Compatibility¶
Cadence Virtuoso Support¶
The first publication of this is missing files required for optimal Cadence Virtuoso usage. These files will be released publicly at a future date after further work (see Issue #1).
These files are;
OpenAccess versions of the cells
Cadence PCells, including
Parameterized primitives including FETs, Capacitors, Resistors, Inductors, etc
Seal Ring
Cadence SKILL scripts that support Virtuoso functions such as netlisting
Before these files are released access to the manually created previous version of these files is available through SkyWater directly under NDA.
Mentor Calibre Support¶
The first publication of this PDK is missing files required to do design verification with Mentor Calibre. Scripts for generating these files from the published documentation will be released at a future date (see Issue #2).
This includes;
Physical checking of design rules
Logic vs schematic checks
Latchup and soft design rules
Fill structure generator
Before the scripts are released which generated the needed files for Mentor Calibre from the release documentation, manually created files which provide similar functionality are available from SkyWater directly under NDA.
Specific Libraries¶
sky130_fd_pr_base¶
See Cadence Virtuoso Support section.
sky130_fd_pr_rf¶
The sky130_fd_pr_rf library is provided for references purposes only, all new designs should be based on the sky130_fd_pr_rf2 library.
See Cadence Virtuoso Support section.
sky130_fd_pr_rf2¶
See Cadence Virtuoso Support section.
sky130_osu_sc - SKY130 Oklahoma State University provided standard cell library¶
The SKY130 Oklahoma State University provided standard cells library is currently empty, only a placeholder is currently provided.
The SKY130 Oklahoma State University provided standard cells library will be integrated at a future date (see Issue #10).
sky130_fd_sp_flash - SKY130 Flash Build Space¶
The flash build space is currently empty, only a placeholder is currently provided.
The components of the SRAM build space compatible with OpenRAM will be released at a future date (see Issue #4).
sky130_fd_sp_sram - SKY130 SRAM Build Space¶
The flash build space is currently empty, only a placeholder is currently provided.
The components of SRAM build space will be released at a future date (see Issue #3).
Design Rule Checking¶
Using Mentor Calibre¶
See Mentor Calibre Support section.
At the moment, if you are required to use Calibre as part of your design flow, it is recommended that you also use the open source tool Magic to check for errors and fix any issues reported.
Using Magic¶
Currently Magic does not have DRC checking rules for checking the specialized exceptions for SRAM cells in the sky130_fd_sp_sram SKY130 SRAM Build Space. These will be released at around the same time as the SKY130 SRAM Build Space.
Scripts and PDK Tooling¶
A number of scripts are used to generate various files in the PDK including many of the liberty, spice files, schematic images, and much more.
These scripts will be published inside the PDK at a future date (see Issue list).