Setup

This repository converts the SkyWater 130 nm PDK into the format required by mflowgen for running a digital flow. mflowgen requires the following files in view_standard directory (for now, we will perform the setup for only regular VT cells, in typical corner). Once complete, your folder should have the following:

adk.tcl
calibre-drc-block.rule
calibre.layerprops
calibre-lvs.rule
magicrc
netgen_setup.tcl
primitives.v
rtk-stream-out.map
rtk-tech.lef
rtk-tech.tf
rtk-typical.captable
stdcells.cdl
stdcells.db
stdcells.gds
stdcells.lef
stdcells.lib
stdcells.mwlib/ # Directory
stdcells.spi
stdcells.v

All of the steps below are automated by scripts in their respective folders. The python and/or shell script can be modified to automate hotfixes as the sky130A pdk is updated.

Running make all will build the entire adk.

Steps

1. Edit the environment variables in setenv.csh to point to the top folder of your PDK repository and open_pdks (or volare) generated sky130A files.
2. make rtk_lef copies the technology lef file into rtk-tech.lef. LEF generation in Innovus requires an OVERLAP layer, and a cut layer is required between the non-routing layers (nwell/pwell/poly) and local interconnect. generate_rtk_lef/generate_rtk_lef.sh performs the hotfixes documented here: google/skywater-pdk-libs-sky130_fd_sc_hd#5.
3. make captable creates rtk-typical.captable. This takes several hours!
4. make lib copies the typical lib file from open_pdks. Note that the copied lib file does not work out-of-box with the commercial tools. Hotfixes are documented in the generate_lib folder's README.md.
5. make sc_lef generates stdcells.lef by copying the open_pdks version.
6. make spi generates stdcells.spi by copying the open_pdks version.
7. make cdl generates stdcells.cdl by copying the open_pdks version.
8. make verilog generates stdcells.v by copying the open_pdks stdcells and primitives verilog files.
9. make db generates stdcells.db using Library Compiler's lc_shell.
10. make milkyway generates stdcells.mwlib and rtk-tech.tf following the steps in generate_milkyway/README.md.
11. make gds generates stdcells.gds by copying the open_pdks version.
12. rtk-stream-out.map in the view-standard directory is copied from https://foss-eda-tools.googlesource.com/skywater-pdk/libs/sky130_osu_sc/+/refs/heads/master/flow/pnr/streamOut.map.
13. adk.tcl is handwritten looking at the lef and lib files.
14. The final files relate to Calibre and Magic to Check DRC and LVS:
    • The final three calibre files are not available yet. We need to create some scripts that generate these files from the technology information in the PDK.
    • As an alternative, we are using magic to check DRCs, and extract a SPICE netlist from the layout and netgen for LVS. Magic needs a .magicrc file to be in the folder from which magic is invoked. Netgen also needs a setup file. These files are obtained by running make magic, which executes the two shell commands below:

cp ${SKYWATER130_HOME}/libs.tech/magic/sky130A.magicrc view-standard/magicrc
cp ${SKYWATER130_HOME}/libs.tech/netgen/sky130A_setup.tcl view-standard/netgen_setup.tcl