In this episode, we’ll dive into two lesser-known but crucial domains in the VLSI industry: Test Chip and CAD Automation. These domains don’t receive as much attention as others, such as STA (Static Timing Analysis), Physical Design (PD), or Verification. However, they are indispensable for the seamless functioning and progress of VLSI technology.
Let’s explore why these domains are essential and how they contribute to the IC design process.
Why These Domains Are Unique :
Test Chip and CAD Automation domains differ from more popular ones as they:
- Require a mix of technical, inter-domain knowledge, and management skills.
- Don’t follow a narrowly focused approach but instead interact with multiple stages of the design process.
- Play behind-the-scenes roles that are critical for validating and optimizing IC designs.
So, let’s begin our exploration!
Test Chip Domain :
The Test Chip domain is fundamental for validating and bench marking the performance of designs, IPs, or innovative technologies.
What Are Test Chips?
Test chips, also called prototype chips, are created to ensure the design fulfills its specifications both in simulations (software) and physical silicon (hardware). These chips can include digital, analog, or mixed-signal designs, and even IPs, to evaluate their functionality against key performance metrics.
Where Test Chip Units Operate in VLSI :
1. ASIC Design Flow:
- In the RTL to GDS2 flow, SoCs (System on Chips) are designed with multimillion gates.
- Test chips here are smaller K-chip designs reused across technology nodes and fabrication processes.
2. Analog Design Flow:
- Test chips in analog design are smaller, focusing on innovations to improve power, timing, and functionality.
- These chips validate improvements across technology nodes and new fabrication techniques.
3. Whole Chip Verification:
- A rigorous verification process encompassing analog, digital, and mixed-signal components.
- Advanced EDA tools and verification techniques are required.
4. DFT (Design for Testability):
- Engineers troubleshoot testability issues, bridging gaps between software simulations and silicon validations.
5. Post-Silicon Validation:
- Involves hands-on testing of physical chips using advanced lab equipment.
- Practical knowledge of tools like oscilloscopes and specialized instruments from vendors like Agilent is essential.
6. Silicon Reporting:
- The final step, where software-to-silicon results are compared and compiled into detailed reports for customers.
- This is a high-responsibility role, requiring years of experience.
CAD Automation Domain :
Computer-Aided Design (CAD) Automation ensures seamless tool integration and workflow efficiency across the VLSI design process.
What Is CAD Automation?
CAD engineers develop and maintain automation frameworks to support various design stages. These frameworks optimize time and resources, allowing designers to focus on creating innovative chips.
Subdomains in CAD Automation:
1. Frontend CAD:
- Covers RTL to synthesis and schematic design flows.
- Requires understanding of EDA tools and continuous updates to automate bug fixes and enhancements.
2. DFT CAD:
- Focuses on automation for smooth DFT inspections and testing.
3. PNR (Place and Route) CAD:
- Automates layout mechanisms for both digital and analog designs.
- Requires knowledge of TCL scripting and proprietary languages like SKILL.
4. Physical Verification CAD:
- Handles DRC (Design Rule Check), LVS (Layout vs. Schematic), and EMIR (Electromigration and IR drop) checks.
- Requires expertise in tools like ICV, PVS, and Calibre.
5. IP View CAD:
- Maintains consistency across multiple views of IPs, ensuring compatibility with various EDA tools and foundry requirements.
6. Design Environment CAD:
- Develops user-friendly interfaces (GUIs) that streamline design workflows, saving designers significant time.
Core Skills for CAD Engineers :
- Scripting Knowledge: Proficiency in scripting languages such as Python, Perl, TCL, and Bash.
- Version Control: Familiarity with systems like CVS or SVN for managing automation repositories.
- Resource Management: Expertise in tools like Univa Grid Engine (UGE) or IBM Load Sharing Facility (LSF) for computational resource optimization.
- Communication and Troubleshooting: Cross-team collaboration and problem-solving skills are critical in resolving complex design challenges.
Conclusion :
Both Test Chip and CAD Automation are pivotal to the VLSI industry’s progress. While these domains might not always be in the spotlight, they are integral to ensuring design accuracy, efficiency, and innovation.
We hope this episode sheds light on these hidden gems of VLSI and helps you explore potential career paths in these exciting fields.
Watch the Video here:
Courtesy: Image by www.pngegg.com
