Overview

This repository runs the following pipecleaner designs through a digital physical design flow using Design Compiler and Innovus with the SkyWater open source 130nm PDK.

• GcdUnit - computes the greatest common divisor function, consists of 100-200 gates
• SramUnit - uses an OpenRAM generated SRAM, plus a simple counter that supplies addresses to it

Setup

To run this flow, please install the following dependencies first in this order:

1. skywater-pdk

Get SkyWater PDK:

git clone https://github.com/google/skywater-pdk.git
cd skywater-pdk

The cell libraries are in submodules that need to be checked out independently:

git submodule update --init libraries/sky130_fd_sc_hd/latest
git submodule update --init libraries/sky130_fd_pr/latest
git submodule update --init libraries/sky130_fd_io/latest

To create the .lib timing files:

make timing
cd ..

2. open_pdks

git clone https://github.com/RTimothyEdwards/open_pdks.git
cd open_pdks
./configure --enable-sky130-pdk=`realpath ../skywater-pdk/libraries` --with-sky130-local-path=`realpath ../PDKS`
make
make install
cd .. 

3. mflowgen - This is a tool to create ASIC design flows in a modular fashion. Follow the setup steps at https://mflowgen.readthedocs.io/en/latest/quick-start.html.

4. skywater-130nm-adk - This repo has some scripts that convert the SkyWater PDK into the format that mflowgen expects. Follow the setup steps at https://code.stanford.edu/ee272/skywater-130nm-adk. The files that are in skywater-130nm-adk/view-standard are the ones that mflowgen will use. (This is configured in the design/construct.py file for each pipecleaner.)

Using the Pipecleaners

First, make sure you update various install paths in the setup.bashrc file. Then source it.

bash
source setup.bashrc

Next, enter into the build directory of the pipecleaner you want to run, and run the following:

cd GcdUnit/build
mflowgen run --design ../design/

Now, if you do make status you will see the status of all the steps in the flow. Use the following make targets to run and debug each step. For example to run step number N do:

make N

Helpful make Targets

• make list - list all the nodes in the graphs and their corresponding step number
• make status - list the build status of all the steps
• make graph - generates a PDF of the graph
• make N - runs step N
• make debug-N - pulls up GUI for the appropriate tool for debugging (at the output of step N)
• make clean-N - removes the folder for step N, and sets the status of steps [N,) to build
• make clean-all - removes folders for all the steps
• make runtimes - lists the runtime for each step