MPW Precheck

Overview

MPW_precheck is a script used to verify a user's design before submission to Tapeout.  It runs a sequence of checks and aborts with the appropriate error message(s) if any of them fails.

The checks are as follows:

• License:
  • The root directory of the project, submodules and third party libraries contain at least one approved license and does not contain any prohibitted license.
  • All source files contain an approved SPDX License and Copyright Headers.
• Makefile:
  • Makefile targets contain at least compression and uncompression for the user_project_wrapper.gds file.
• Defaults:
  • Contents of the project are different from the default content in caravel_user_project for digital projects and caravel_user_project_analog.
  • The user_project_wrapper.gds must be different from the default one found in caravel_user_project for digital projects and caravel_user_project_analog for analog projects.
• Documentation:
  • Documentation file README.md exists and does not use any non-inclusive language.
• Consistency:
  • Runs a series of checks on the user netlist (user_project_wrapper/user_analog_project_wrapper), and the top netlist (caravel/caravan) to make sure that both conform to the constraints put by the golden wrapper.
    • Both Netlists share the following checks:
      • Modeling check: check netlist is structural and doesn't contain behavioral constructs.
      • Complexity check: check netlist isn't empty and contains at least eight instances.
    • Remaining Top Netlist checks:
      • Sub-module hooks: check the user wrapper submodule port connections match the golden wrapper ports.
      • Power check: check all submodules in the netlist are connected to power.
    • Remaining User Netlist checks:
      • Ports check: check netlist port names match the golden wrapper ports.
      • Layout check: check netlist matches the provided user wrapper layout in terms of the number of instances, and the instance names.
• GPIO Defines:
  • A verilog directives check that validates the project's 'verilog/rtl/user_defines.v' netlist.
• XOR:
  • No modification in the user_project_wrapper (versus default user_project_wrapper.gds in caravel_user_project for digital projects. and caravel_user_project_analog for analog projects) outside the user defined area lower left corner (0,0) and upper right corner (2920, 3520).
• Magic DRC:
  • The user_project_wrapper.gds does not have any DRC violations(using magic vlsi tool).
• KLayout BEOL DRC:
  • The user_project_wrapper.gds does not have any DRC violations(using klayout) in the Back End Of Line layers.
• KLayout FEOL DRC:
  • The user_project_wrapper.gds does not have any DRC violations(using klayout) in the Front End Of Line layers.
• KLayout Off Grid:
  • The user_project_wrapper.gds does not contain any shapes that have offgrid violations(rules x.1b, x.3a, x.2, x.2c).
• KLayout Metal Minimum Clear Area Density:
  • The user_project_wrapper.gds has metal density (for each of the 5 metal layers) that is the lower than the maximum metal density specified by the li1.pd.ld, m1.pd.ld, m2.pd.ld, m3.pd.ld, m4.pd.ld, m5.pd.ld rules.
• LVS:
  • Runs hierarchy check, soft check, lvs check, ERC check on the user project. For more information click here.
  • If running precheck from user project Makefile, LVS can be disabled by using DISABLE_LVS environment variable. The user must understand this is risky to the operation of the final chip and should only be done in a very reasoned manner under very specific conditions.
• OEB:
  • Runs oeb check, to make sure that user connected all needed oeb signals. For more information click here.

###Current Assumptions

• The user module name is user_project_wrapper (or user_analog_project_wrapper for caravel_user_project_analog)
• The mpw precheck is executed from inside its docker container where a golden copy of caravel exists and is specified by an environment variable called GOLDEN_CARAVEL.

LVS Configuration

In order for LVS and OEB checks to run successfully, the user must provide an lvs configuration file that describes the hierarchy of the design and give necessary information for running the checks. For extra information on how to write the configuration file click here.

Download

MPW Precheck can be found on GitHub here.

Installation

Prerequisites

• Docker

Setup

Docker

You can either build the docker locally or fetch it from dockerhub.

• Build Docker Locally

  To build the necessary docker locally, run:

  cd dependencies
  sh build-docker.sh
  

• Pull Docker from Dockerhub    To pull the necessary docker from dockerhub, run:

  docker pull efabless/mpw_precheck:latest
  

Install the PDK

If you don't have the pdk installed, please refer to the Caravel Makefile.

Before Using

Before you run the precheck tool, make sure you go through https://opensource.google/docs/releasing/preparing/ and cover the requirements.

Overwrite verilog/gl/user_project_wrapper.v with your synthesized netlist make sure the netlist includes power information. Keep on reading for this point to make more sense.

Make sure you have the top level GDS-II under a directory called gds/; thus containing gds/user_project_wrapper.gds, this directory should be compressed and the script will use your Makefile to uncompress it.

Please create a file ./third_party/used_external_repos.csv and add to it all repository name, commit hash for any external github repository that you are using to build this project.

Please include any useful statistics about your design, i.e. cell count, core utilization, etc. in a .csv file under ./signoff/<macro-name>/final_summary_report.csv. If you're using OpenLANE then, this file should be created automatically in <run path>/reports/final_summary_report.csv.

How To Run

Mount the docker file:

export PDK_PATH=<Absolute path to the desired PDK 'variant specific'.>

export INPUT_DIRECTORY=<Absolute path to the user project path>

sh docker-mount.sh

Run the following command:

usage: mpw_precheck.py [-h] --input_directory $INPUT_DIRECTORY --pdk_path $PDK_PATH [--output_directory OUTPUT_DIRECTORY] [--private] [check [check ...]]

Runs the precheck tool by calling the various checks in order.

positional arguments:

  check                 Checks to be ran by the precheck (default: None)

optional arguments:

  -h, --help               show this help message and exit

  -i, --input_directory    $INPUT_DIRECTORY
                           INPUT_DIRECTORY, absolute Path to the project. (default: None)

  -p, --pdk_path           $PDK_PATH
                           PDK_PATH, points to the installation path of the pdk 'variant specific' (default: None)

  -o, --output_directory   OUTPUT_DIRECTORY
                           OUTPUT_DIRECTORY, default=<input_directory>/precheck_results. (default:None)

  --private                If provided, precheck skips [License, Defaults, Documentation]
                           checks used to qualify the project to as an Open Source Project (default: False)

How to Troubleshoot Issues with Precheck

See the following document for guidance on troubleshooting issues with precheck.