Skip to content
BranchesTags

Repository files navigation

UWASIC Design Template

A template for mixed-signal ASIC design using open-source tools, featuring automated workflows for digital, analog, and integration for TinyTapeout chip projects.

Overview

The UWASIC template provides a structured approach to ASIC design with three distinct workflows:

  • Digital flow: RTL-to-GDS using OpenLane2
  • Analog flow: Schematic-driven layout using Xschem/Magic
  • Mixed-signal flow: Combined analog and digital designs
  • TinyTapeout integration: Tapeout-ready chip submission to Efabless

Table of Contents

Quick Start [Do this first after Environment Setup]

Navigate to the flows/ directory and choose your project type:

cd flows/

# Digital-only project
make CreateProject PROJECT_NAME=my_counter PROJECT_TYPE=digital

# Analog-only project
make CreateProject PROJECT_NAME=my_opamp PROJECT_TYPE=analog

# Mixed-signal project (digital + analog)
make CreateProject PROJECT_NAME=my_processor PROJECT_TYPE=mixed

View Available Commands

make help                    # Show all available commands
make status                  # Show current project modules and their parents
make DeleteAll              # Clean up all projects

Environment Setup

Installing Nix Package Manager

The template uses Nix to ensure consistent tool versions across all platforms.

Linux Installation
# Install Nix (single-user)
sh <(curl -L https://nixos.org/nix/install) --no-daemon

# Enable flakes
mkdir -p ~/.config/nix
echo "experimental-features = nix-command flakes" >> ~/.config/nix/nix.conf

# Restart shell
exec $SHELL
macOS Installation
# Due to finicky mac support,
# all mac users must run a docker wrapper around nix-shell
# Which makes it slower, but usable!
chmod +x mac_shell.sh
./mac_shell.sh
Windows Installation (via WSL2)
# In PowerShell as Admin
wsl --install

# Restart, then in WSL2 Ubuntu:
sh <(curl -L https://nixos.org/nix/install) --no-daemon

# Enable modern Nix features
mkdir -p ~/.config/nix
echo "experimental-features = nix-command flakes" >> ~/.config/nix/nix.conf

# Restart your shell
exec $SHELL
Entering the Nix Environment

From the project root:

# For WSL and Linux users
nix-shell

# For macos
./mac_shell.sh # This will always be your entry instead of nix-shell

# NOTE: Whenever you get python installation errors of UWASIC-ALG or gmid, then you need to,
rm -rf .venv
# Then re-run the shell

This provides all necessary tools:

  • Digital: OpenLane2, Yosys, Icarus Verilog, cocotb, slang
  • Analog: Xschem, Magic, ngspice, netgen, KLayout
  • Verification: CACHE, OpenSTA

Project Management

Project States

The template tracks project state automatically:

  • none: No projects created
  • digital: Digital-only project
  • analog: Analog-only project
  • mixed: Combined digital + analog project

Project Structure

After creating projects, your directory structure will be:


uwasic-template/
├── .github/ # Automated workflows
├── shell.nix # Nix environment configuration
├── flows/ # Project management system
│ ├── Makefile # Main project commands
│ └── templates/ # Project templates
├── digital/ # Digital design projects
│ └── project_name/
│ ├── build/ # Build system (synthesis, verification)
│ ├── src/ # RTL source files
│ └── test/ # Testbenches and verification
├── analog/ # Analog design projects
│ ├── library/ # Shared analog IP library
│ ├── build/ # Build system (layout, validation)
│ ├── layout/ # Magic layout files
│ ├── schematics/ # Xschem schematic files
│ └── symbols/ # Xschem symbol files
└── caravel/ # TinyTapeout submission package
├── src/ # Verilog wrapper and sources
├── analog/ # Copied analog project files
├── docs/ # Documentation
└── info.yaml # TinyTapeout project configuration

Design Rules

  1. Digital Projects:

    • Can have child analog modules with PARENT parameter
    • Use src/ directory for internal submodules

  2. Analog Projects:

    • Child modules automatically symlink .gds files to parent's layout/dep/ directory

  3. Mixed-Signal Projects:

    • Combine both analog and digital components
    • Digital components must implement TinyTapeout interface

Digital Workflow

Overview

The digital flow uses OpenLane2 for automated RTL-to-GDS conversion with comprehensive verification. However, the final conversion will be done with github workflows after caravel/ is formed and it is pushed.

Directory Structure


digital/
└── <project_name>/
├── build/ # Build system
│ ├── config.mk # Project configuration
│ ├── des_tb/ # RTL simulation
│ ├── lint/ # Static analysis
│ ├── synthesis/# Physical synthesis
│ └── verification/ # Formal verification
├── src/ # RTL source files (.v, .sv)
└── test/ # Testbenches and cocotb tests

Workflows

If you haven't created it refer to the Quick-Start
1. RTL Simulation
cd digital/your_project/build/des_tb
make test-rtl
2. Linting
cd digital/your_project/build/lint
make lint
3. Local Synthesis and Implementation [Delete its output before pushing]
cd digital/your_project/build/synthesis
make synthesis    # Synthesis only
make harden      # Full flow to GDS
4. Verification
cd digital/your_project/build/verification
make verification

Analog Workflow

Overview

The analog flow uses Xschem for schematic capture and Magic for layout, with comprehensive DRC/LVS verification.

Directory Structure

analog/
├── library/          # Shared analog IP library
├── build/
│   ├── config.mk     # Project configuration
│   ├── layout/       # Layout tools
│   ├── schematic/    # Schematic tools
│   └── validation/   # DRC/LVS verification
├── layout/           # Magic layout files (.mag)
├── schematics/       # Xschem schematics (.sch)
│   └── testbenches/  # Testbench schematics
└── symbols/          # Xschem symbols (.sym)

Workflows

If you haven't created it refer to the Quick-Start
1. Schematic Capture
cd analog/build/schematic
make setup        # Organize files
make schematic    # Open Xschem
2. Layout Design
cd analog/build/layout
make layout       # Open Magic
3. SPICE Simulation
cd analog/build/schematic
make spice        # Run simulations
4. Physical Verification
cd analog/build/validation
make magic_test          # Magic DRC/LVS
make klayout_test        # KLayout verification
make full_verification   # Complete suite

Mixed-Signal Workflow

Mixed-signal projects combine digital and analog designs into a single tapeout-ready submission.

Creating Mixed-Signal Projects

# Create mixed-signal project with both components
make CreateProject PROJECT_NAME=mixed_adc PROJECT_TYPE=mixed

# Add additional modules as needed
make AddModule MODULE_NAME=adc_core MODULE_TYPE=analog PARENT=mixed_adc
make AddModule MODULE_NAME=digital_filter MODULE_TYPE=digital PARENT=mixed_adc

# Create TinyTapeout integration
make CreateCaravel PROJECT_NAME=tt_mixed_adc

Project State Tracking

The template automatically tracks project states and allows:

  • Multiple analog modules with parent-child relationships
  • Digital modules that implement TinyTapeout interface
  • Automatic integration of both domains in Caravel generation

TinyTapeout Integration

TinyTapeout integration creates submission-ready packages for the Efabless shuttle program. The template automatically generates proper pin assignments, power connections, GitHub Actions workflows, and project configuration files.

TinyTapeout's info.yaml

Digital Projects

  • Interface: Standard TinyTapeout digital interface (8 inputs, 8 outputs, 8 bidirectional)
  • Tile Configuration: 1x1 tiles for digital projects
  • Testing: Includes gate-level testing workflows

Analog Projects

  • Pin Assignment: Uses ua[5:0] analog pins (configure count in info.yaml)
  • Power Connections: Includes VGND, VDPWR, and VAPWR connections
  • Tile Configuration: Defaults to 1x2 tiles for analog projects
  • Pin Limits: Up to 6 analog pins
Power Connections

Mixed-Signal Projects

  • Tile Configuration: 2x2 tiles for mixed projects
  • Analog Interface: Proper ua[] pin assignments
  • Digital Integration: Complete TinyTapeout digital interface
  • Power Distribution: Separate analog and digital power domains

Workflows and CI/CD

The template automatically generates GitHub Actions workflows based on project type for automated verification and tapeout preparation.

Automated Workflow Generation

When you create a TinyTapeout project, appropriate workflows are automatically generated but are only run on the caravel/ directory, so you need to create one:

make CreateCaravel PROJECT_NAME=my_chip

Generated Workflows

Universal Workflows (All Project Types)

  • gds.yaml: GDS generation and precheck using TinyTapeout actions
  • docs.yaml: Documentation generation workflow

Digital/Mixed-Signal Workflows

  • test.yaml: RTL simulation using Icarus Verilog + cocotb
  • fpga.yaml: FPGA implementation for ICE40UP5K platform

Workflow Features

  • Automated Testing: RTL and gate-level simulation
  • FPGA Prototyping: Automatic bitstream generation
  • Analog Characterization: Automated circuit parameter extraction
  • Documentation: Automatic generation of project documentation
  • Tapeout Preparation: GDS generation with precheck validation

Debug Commands

Check current project state:

make status

View all available commands:

make help

Clean up and restart:

make DeleteAll

Examples

Complete Digital Project Example

# Create digital project
make CreateProject PROJECT_NAME=counter_demo PROJECT_TYPE=digital

# Implement your counter in digital/counter_demo/src/counter_demo.v
# Create tests in digital/counter_demo/test/

# Create TinyTapeout integration
make CreateCaravel PROJECT_NAME=tt_counter_demo

# Check status
make status

Complete Analog Project Example

# Create analog project
make CreateProject PROJECT_NAME=amplifier PROJECT_TYPE=analog

# Create TinyTapeout integration
make CreateCaravel PROJECT_NAME=tt_amplifier

# Check status
make status

Complete Mixed-Signal Project Example

# Create mixed-signal project
make CreateProject PROJECT_NAME=mixed_adc PROJECT_TYPE=mixed

# Add additional modules
make AddModule MODULE_NAME=digital_filter PARENT=mixed_adc

# Create TinyTapeout integration
make CreateCaravel PROJECT_NAME=tt_mixed_adc

# Check status
make status

Resources

About

No description, website, or topics provided.

Resources

Readme
Activity

Stars

0 stars

Watchers

0 watching

Forks

0 forks
Report repository

Releases

Packages

Contributors

Languages

Generated from UW-ASIC/TinyTapeout_Flows