The KLayout that comes with OpenLane-2 Nix/Docker does not have Qt5 support, which is required for the Sky130 technology files and the 2.5D viewing. You will need to install KLayout from the KLayout website. It is pre-built for nearly all platforms (Windows, MacOS, Linux) and is easy to install.
- Windows 64-bit: klayout-0.29.4-win64-install.exe
- Ubuntu 20.04: klayout-0.29.4-1_amd64.deb
- MacOS: Depends on your OS Version. Check the KLayout website for the latest version.
We have tested with version 0.29.4. While this is not the newest, it is the same as the version used in OpenLane-2, so it should be compatible.
WARNING: If you install another version, you must UNINSTALL KLayout before using OpenLane-2 in subsequent parts of the class. Or, at least, remove it from your PATH. The OL2 developers use locally installed executables instead of the ones in the Docker container when they exist. You may run into problems during KLayout steps in OL2 if you do not do this!
Clone this repository to your local machine:
git clone https://github.com/VLSIDA/chip-tutorials.git
cd chip-tutorials/klayoutThe subdirectory tech contains the Sky130 technology files for
KLayout in one convenient place. You can start KLayout and have it use these by
running the following command:
KLAYOUT_PATH=<chip-tutorials dir>/klayout klayout -ewhere "" refers to the chip-tutorials repos location. If you don't specify the KLAYOUT_PATH variable, it will use the tech directory in your home directory which likely does not exist.
Alternatively to avoid having to set KLAYOUT_PATH every time, you can set it
at the bottom of your ~/.bashrc file (or ~/.zshrc for MacOS and zsh users) with:
export KLAYOUT_PATH=<chip-tutorials dir>/klayoutYou must specify the "-e" argument to enable edit mode. Otherwise, KLayout is just started in read-only (viewer) mode.
You will then be greeted with the main KLayout window:
You may get the following error if you try to run KLayout from the docker.
Authorization required, but no authorization protocol specified
Could not load the Qt platform plugin "xcb" in "" even though it was found. You can resolve this by running:
xhost +local:This will give the docker container permission to access your display server (X11).
You can open a GDS file by selecting File -> Open and selecting the GDS file you want to open. Select
the GDS file in the klayout subdirectory called 'sky130_fd_sc_hd__inv_1.gds' and you will see the following:
On the right, you should see the "Layers" palette. However, this includes a lot of layers that are not used and are grayed out. To only show the layers that are used in the cell click, right click any layer and select "Hide Empty Layers". You should now see:
If you double click on any layer, it will make it invisible. If you double click again, it will make it visible. You can also select multiple layers by holding down the shift key and selecting a range, or holding down the control key and selecting individual layers.
If the Sky130 technology files are properly loaded, you should see a menu called "Efabless sky130" with the following contents:
The 2.5D viewer lets you look at and interact with a "3D" view of the layout:
This is useful for seeing how the the cell will look with the z-dimension information. Note that commercial tools do not have this feature and it is only really used for educational purposes.
The Running DRC tutorial discusses how to run Design Rule Checks (DRC) in KLayout with Sky130. The Edit tutorial has some useful instructions for editing shapes in the layout which can be used to fix DRC errors.
The Running LVS tutorial discusses how to run LVS as well as some common errors and how to fix them.
For some reason, on my Ubuntu machine, KLayout crashes when I close it. I get this window and must select "Cancel" to fully exit out:
Copyright 2024 VLSI-DA (see LICENSE for use)