Exploring VLSI Domains and Skill Sets: ASIC & FPGA

 

In this, we’ll explore the various domains in VLSI (Very Large Scale Integration) where you can build a career. Additionally, we’ll break down the specific skill sets needed for each domain. This topic stems from a viewer's request to clarify what professionals do in different VLSI domains like design, verification, and physical design. 

Since this is a broad topic, we’re dividing it into multiple posts. This blog is part one, so stay tuned for future installments!

Introduction to VLSI Domains: A Bird's Eye View

The VLSI ecosystem is vast and can be broadly divided into several domains:

1. Digital Design:

Digital design caters to various chip technologies like ASIC (Application-Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), and SoC (System-on-Chip).  The digital design flow typically starts with RTL (Register Transfer Level) coding and ends with a GDSII (Graphic Data System) file for fabrication.

2. Analog Design :

In analog design, engineers work on components like PLLs (Phase-Locked Loops), op-amps, and oscillators. These components are crucial for circuits that process analog signals.

3. Analog Mixed-Signal (AMS) Design

AMS design combines analog and digital techniques, widely used in technologies like USB, SerDes, and IP cores. This domain bridges the gap between digital and analog design.

4. IP Design and Characterization :

IP (Intellectual Property) design involves creating reusable design blocks, such as:

• Digital IP: Logic gates, sequential elements.
• Analog IP: Converters (ADC/DAC), PLLs, memory cells.

5. Test Chip Development :

Test chips are prototypes that test designs on actual silicon. They validate performance by comparing test outcomes with simulation results, providing critical feedback for final production.

6. CAD and Automation :

CAD (Computer-Aided Design) automation tools form the backbone of all VLSI domains. Proficiency in these tools is essential across the board.

Domains Within Digital Design:

Let’s dive deeper into digital design, which spans multiple specialized domains:

1. RTL Design :

•  What It Entails: Writing hardware description languages (HDLs) like Verilog, VHDL, or SystemVerilog to define the chip’s behavior.
• Skills Needed: 
•  Advanced expertise in HDLs.
•  Strong problem-solving skills to design complex circuits.

2. Verification :

• What It Entails: Ensuring the chip design meets its specifications through methodologies like UVM (Universal Verification Methodology) and OVM (Open Verification Methodology).
• Skills Needed: 
• System Verilog assertions.
• Knowledge of LRMs (Language Reference Manuals) to stay updated with industry changes.

3. DFT (Design for Testability) : 

• What It Entails: Designing chips with built-in testing features for post-manufacturing validation.
• Skills Needed: Familiarity with tools like Tetramax and concepts like ATPG (Automatic Test Pattern Generation), BIST (Built-In Self-Test), and JTAG (Joint Test Action Group).

4. Physical Design :

• What It Entails: Translating RTL designs into layouts for fabrication. This stage includes:
• PNR (Place and Route).
• CTS (Clock Tree Synthesis).
• ECO (Engineering Change Order).
• Skills Needed: Tools like Cadence Encounter or Synopsys ICC2.

5. Physical Verification

• What It Entails: Verifying the layout with checks like:
• DRC (Design Rule Check).
• LVS (Layout vs. Schematic).
• ERC (Electrical Rule Check).
• Skills Needed: Tools such as IC Validator and PERC.

6. STA (Static Timing Analysis)

• What It Entails: Analyzing timing paths to ensure designs meet speed and performance goals.
• Skills Needed: Mastery of tools like PrimeTime and ETS

 7. Sign-Off :

• What It Entails: Finalizing the design for tape-out (fabrication). Engineers in this domain require comprehensive knowledge of the RTL-to-GDSII flow.
• Skills Needed: Tools like LEC (Logical Equivalence Check) and IREM.

Final Thoughts:

Each VLSI domain offers unique challenges and opportunities. While large companies often have specialized teams for each domain, startups may require engineers to handle multiple responsibilities. The choice of domain depends on your interest and expertise.

Stay tuned for upcoming blogs where we’ll discuss analog design, AMS design, and other key domains in detail. 

Let’s simplify VLSI, one domain at a time. Until next time, happy learning! 😊

Watch the video here:

Courtesy: Image by www.pngegg.com

Read More

How Difficult Is It to Start an IP Business? A Viewer Question Answered

 

Welcome to today’s blog, inspired by a question from one of our viewers, who asked: “How difficult is it to start an IP business?” We appreciate Andre for bringing up such an insightful topic! While this isn’t a step-by-step guide, we aim to provide an overview of what it takes to venture into the world of Intellectual Property (IP) business. Let’s dive in!

The Three Pillars of Starting a Business:

Starting any business revolves around three key elements: Finance, Contacts, and Expertise. Let’s break these down:  

1. Finance

Finance is the backbone of any business. Whether it’s renting or buying premises, obtaining tool licenses, or hiring a skilled team, everything requires capital. Even with solid expertise and a robust business plan, money is essential to bring your ideas to life.  To kick start your IP business, focus on organizing your finances and drafting a comprehensive business plan. While we aren’t finance experts, we recommend consulting with professionals to ensure your plan is sustainable.  

2. Contacts (Networking)

Networking plays a crucial role in building your business. If you’ve been part of the industry for a while, your professional relationships can become valuable resources. These connections can help at various stages of your business, from securing clients to overcoming challenges.

3. Expertise

Expertise is indispensable. Many successful IP entrepreneurs are seasoned professionals with over a decade of experience in the field. If you don’t have significant expertise, collaborating with or hiring experts is a viable path.  

Understanding IP in VLSI:

When it comes to IP in Very Large-Scale Integration (VLSI), the offerings typically fall into two categories: Soft IP Cores and Hard IP Cores.

1.Soft IP Cores  

These are synthesizable RTL models, developed in hardware description languages like SystemVerilog or VHDL. They can also be offered as generic gate-level netlists, making them adaptable to different process technologies. The flexibility of soft IP cores allows customization during back-end placement and routing.  

2. Hard IP Cores  

These are layout designs provided in formats like GDS, pre-mapped to a specific process technology. Unlike soft IP cores, hard IP cores cannot be customized for different technologies and are ready to integrate directly into the chip’s final layout.  

Building the Right Teams:

To deliver high-quality IPs, you need specialized teams:  

1. Front-End Team  

Focuses on RTL design, verification, synthesis, pre-layout static timing analysis, and DFT (Design for Testability).  

2. Back-End Team  

   Handles placement and routing (P&R), layout, DRC/LVS checks, parasitic extraction, post-layout timing analysis, physical verification, and tape-out processes.  

3. CAD Team  

Manages automation, tool installation, license management, and quality control.  

4. IP Delivery and Support Team  

Ensures smooth delivery and addresses customer issues with application engineers.  

5. Additional Support Teams  

• HR for hiring and employee management.  
• System administrators for IT infrastructure.  
• Admin personnel for day-to-day logistics.  

6. Licensing and Business Models

An essential aspect of running an IP business is addressing licensing and permission-related issues, tailored to your chosen business model. Whether you opt for perpetual licenses, subscription models, or usage-based licenses, clarity in terms and support is critical.  

Wrapping Up  :

The question about the difficulty of starting an IP business doesn’t have a one-size-fits-all answer. As we’ve outlined, the challenges you face will depend on your resources, industry experience, and ability to adapt to the journey’s demands.  

We hope this overview provides valuable insights and helps you make informed decisions. Thanks for engaging with us, and we’ll see you in the next episode of our Q&A series. Until then, stay tuned and stay focused!

Watch the video here:

Courtesy: Image by www.pngegg.com

Read More

Navigating Job and Internship Applications in the VLSI Industry: Tips and Insights

Hello, and welcome to today’s blog! If you’ve been facing challenges in landing a job or internship in the VLSI industry, you’re not alone. One of our readers, raised an important question:  

"I’m applying for internships and jobs but haven’t received any callbacks. What should I do?"  

This is a common scenario for many job seekers. In this post, we’ll explore the potential reasons behind this and provide actionable strategies to enhance your application process.  

Understand the Hiring Process: The Virtual Reality Gap  

When applying for roles on job portals or LinkedIn, it’s important to recognize that these platforms operate in a virtual realm. Unlike direct, face-to-face communication, there are multiple non-human layers between you and the recruiter, which can delay responses.  

Here’s what often happens behind the scenes:  

1. Recruiters Post Across Multiple Platforms:  

Recruiters share job openings on various sites, including LinkedIn and job portals. They then need to manually log in to each platform, collect applications, and process them—a time-consuming task.  

2. Indirect Communication:  

The delay isn’t personal. It’s a systemic issue caused by managing data across platforms. Understanding this can help you remain patient and proactive without feeling disheartened.  

What Can You Do? Proactive Steps to Take :

To bridge the communication gap, here are some practical strategies:  

1. Directly Connect with Recruiters  

• Use platforms like LinkedIn to reach out to recruiters who posted the job. Send a polite connection request and a personalized message mentioning your application.  
• If you have their email, draft a formal inquiry to ask about the application status. 

2. Follow Up Regularly  

• If you don’t receive a response, follow up every 15 days. Keep your tone professional and inquisitive rather than demanding.  

     Example: “Dear [Recruiter’s Name], I hope this message   finds you well. I wanted to follow up on my application for     [Position]. Could you kindly provide an update?”  

Managing Expectations: Convergence vs. Divergence  

Recruiters and applicants often align—or diverge—based on timelines and expectations. Let’s examine three scenarios:  

1. Aligned Timelines (Convergence):  

If both you and the recruiter have similar expectations and timelines, the hiring process is likely to progress smoothly.  

2. Flexible Timelines (Potential Convergence):  

If your availability aligns with the recruiter’s timeline, even if it’s not exact, there’s still a high chance of success.  

3. Conflicting Timelines (Divergence):  

When timelines are misaligned, such as the recruiter needing someone immediately while your availability is months away, the process may not move forward.  

Broadening Your Perspective : 

Many job postings are tied to long-term projects with fluctuating timelines. Here are some insights to keep in mind:  

• Project Timelines:  

   Sometimes, hiring for a role is delayed due to shifts in project schedules. For example, a position posted in January might not be filled until months later due to internal changes.  

• Urgent Hiring:  

  If the project start date is approaching, the hiring process might accelerate, leaving little room for delays between interview rounds.  

To navigate these uncertainties, focus on starting conversations with recruiters and seeking clarity about the status of your application.  

Diversify Your Applications :

• Apply to multiple positions across various companies and platforms.  
• Join Telegram or WhatsApp groups where recruiters frequently post job openings.  
• Leverage professional networks to discover opportunities.  

Final Tips for Professional Communication : 

When following up or reaching out, keep these points in mind:  

•  Be formal and polite in your tone.  
• Show enthusiasm for the role without appearing pushy.  
•  Maintain a balance between persistence and patience.  

Conclusion : 

The key to navigating job applications lies in managing both your mindset and your approach. By understanding the virtual hiring process, staying proactive, and maintaining professionalism, you can significantly improve your chances of success. If you found this blog helpful, share it with your network.  Good luck with your applications, and see you in the next post! 🚀  

Watch the video lecture here:

Courtesy: Image by www.pngegg.com

Read More

How to Secure an Internship Without Personal Connections: A Practical Guide

Internships are a crucial part of an undergraduate’s journey, especially for students in fields like Electrical and Electronics and Communication (EC). 

However, many students often wonder: "How do I get an internship if no company visits my campus?" 

This blog addresses this common concern and offers a step-by-step guide to finding internships independently, focusing on using LinkedIn as a powerful tool.  

Debunking the Myth: 

Campus Placements Are Not the Only Way. A prevalent misconception among students is that companies must come to their campuses to offer internships. While campus placements can be helpful, they are not the only avenue. In reality, there are several ways to find internships, even without any personal connections.

Using LinkedIn to Search for Internships:

LinkedIn is an invaluable resource for students and professionals seeking internships or job opportunities. Here’s how to leverage it effectively:  

1. Log In to LinkedIn : 

 After logging into your account, navigate to the "Jobs" section   from the homepage.  

2. Use the Search Bar : 

Enter relevant keywords in the search bar, such as "Analog Design," "Digital Design," or "Memory Design." Ensure that the keywords align with your domain and interest area.  

3. Apply Filters  : 

On the left-hand side, you’ll find various filters. To focus on internships, check the "Internship" box under the job type filter.  

4. Explore Opportunities  :

After applying the filters, LinkedIn will display a list of available internships. You’ll see openings from multiple companies, making it easier to compare and select positions that interest you.  

5. Submit Your Application  

• Easy Apply Option: Some companies allow you to apply directly through LinkedIn using the "Easy Apply" button. Simply upload your resume, and you’re done.  
• Redirect to Company Website: If the "Easy Apply" option isn’t available, clicking "Apply" will redirect you to the company’s official website. There, you may need to create an account and submit your application.  

Tips for Optimized Internship Searches

1. Choose the Right Keywords  

Your search terms should be specific to your field and interests. For instance, if you’re interested in "Digital Design," use it as a keyword. Changing the keywords can yield a variety of results.  

2. Prepare Your Resume  

Before you start applying, ensure that your resume or bio-data is updated and tailored to the internships you’re targeting.  

3. Be Realistic About Responses  

Not every application will result in a callback. Generally, you can expect a 5% success rate. This means that if you apply to 100 positions, around five may lead to interviews or offers.  

Staying Motivated: A Balanced Approach :

It’s natural to feel disheartened if you don’t get immediate responses. However, it’s essential to maintain a realistic mindset. Avoid extremes of optimism ("I’ll get selected for every position") or pessimism ("I’ll never get selected"). Instead, focus on consistent effort and continuous improvement.

Key Takeaways :

• Use platforms like LinkedIn to search for internships beyond your campus.  
• Apply targeted filters to narrow your search.  
• Update your resume and apply to as many relevant positions as possible.  
• Be patient and persistent. Not every application will yield results, but each one brings you closer to your goal.  

Conclusion :

Finding an internship without personal connections may seem challenging, but with the right tools and strategies, it’s entirely achievable. Follow the steps outlined above, and you’ll increase your chances of landing an internship that aligns with your career aspirations. If you found this guide helpful, don’t forget to share it with your friends and peers. Good luck, and happy interning!  

Watch the video lecture here:

Courtesy: Image by www.pngegg.com

Read More

How to Start Your Journey in VLSI as an Undergraduate?

Hello everyone! Welcome to another blog post where we address your questions and explore the world of technology. Today, we’re diving into an excellent query from one of our young readers, who asked:  

"I'm an undergraduate student. What should I learn to pursue a career in VLSI?"  

This is a great question, and while it seems simple, the answer is quite detailed. In this blog, we'll break it down step by step to give you a comprehensive guide. So, stick around till the end!  

Importance of Academic Foundation :

Before anything else, focus on excelling in your coursework. A solid academic record not only builds foundational knowledge but also makes a strong impression during interviews. Prioritize your studies and aim for good grades - this is non-negotiable.  

VLSI: Broad Categories of Design:

The VLSI (Very-Large-Scale Integration) field is vast, and to navigate it, you must understand its three primary domains:  

1. Digital Electronics  

2. Analog Electronics  

3. Analog Mixed Signal (AMS) Electronics  

Each domain has unique challenges and learning paths. Let’s explore them one by one.  

1. Digital Electronics:  

If you enjoy working with logic gates and digital circuits, this might be your calling. In the digital domain, you can specialize in:  

Front-End Design: Focus on coding and programming languages like Verilog, VHDL, and SystemVerilog. Learn about verification methodologies such as UVM (Universal Verification Methodology) and OVM (Open Verification Methodology). Knowledge of scripting languages like Python and Ruby is also beneficial.  

Back-End Design : Dive into physical design, which involves creating stick diagrams, layouts, static timing analysis (STA), and physical verification. This path is ideal if you’re inclined towards understanding the physical processes of chip design.  

2. Analog Electronics :  

If circuits like op-amps, oscillators, and PLLs fascinate you, consider analog design. Key skills include:  

- Mastering circuit theory and concepts like Kirchhoff’s Current and Voltage Laws.  

- Learning simulation tools such as LTspice for schematic design and analysis.  

- Understanding SPICE language for circuit modeling and verification.  

3. Analog Mixed Signal (AMS) Electronics :  

This domain bridges digital and analog electronics. It’s particularly relevant as the industry progresses toward advanced technology nodes like 5nm. A career in AMS requires expertise in both digital and analog skills for designing and verifying systems.  

Continuous Learning and Staying Updated :

VLSI is a dynamic field with constant innovations. Stay updated by subscribing to semiconductor news forums and participating in technical communities.  

Final Advice:

Choose a path that aligns with your interests, whether it's front-end, back-end, analog, or AMS. Once you identify your natural inclination, dive deep into learning and practice. Remember, this is a long-term journey, and persistence is key.  

We hope this post has clarified how to begin your VLSI career as an undergraduate. See you in the next post! 😊  

Watch the video lecture here:

Courtesy: Image by www.pngegg.com

Read More

Power Domains & Power Modes : UPF Episode - 5

In this enlightening episode, we delve into a series of intriguing topics that shed light on the fascinating realm of power domains and power modes in VLSI (Very Large Scale Integration). Inspired by a question posed by Sandeep Vasireddy during the inaugural episode of the UPF (Unified Power Format) in VLSI Series, we embark on a comprehensive exploration of power modes. Through a meticulous analysis, we unravel the concept of power modes, including their definition and significance in VLSI design. We also delve into the realm of popular power modes, exploring various examples and their applications within the industry. Furthermore, we delve into the intricacies of power domains, examining their fundamental nature and the criticality of power-up and power-down sequencing in VLSI systems. By the end of this episode, viewers will have gained a solid understanding of power modes and power domains, enabling them to apply this knowledge effectively in their own VLSI designs.

What is Power Mode ?

Power management is a feature that resides in modern electronic circuits residing inside copiers, laptop, Smart Phones, CPUs, GPUs, monitor , printer, that turns off the power partially or as a whole when inactive. Sleep mode is a low power mode for electronic devices. These modes save significantly on electrical consumption compared to leaving a device fully on.  Sleep mode also known by various names, including Stand By, Suspend and Suspend to RAM. Power mode names may vary from one IC/IP to another IC/IP. For any Specific IC , please consult the Data-Sheet to understand its power modes & its corresponding operations. To know the power-modes of any IP, you must contact the IP-Vendor for the respective Application Note on the available Power-Modes.

Popular Power Modes:

1. Idle Mode:

   -Stopped: CPU, Flash memory

   -Running: Comparator, ADC , Watchdog-Module

   -Wakeup:  External and internal interrupts

2. Power-Down Mode:

   -Stopped: All major & minor powered blocks

   -Running: External interrupts, Watchdog-Module

   -Wakeup: Watchdog-Module, External Interrupt

3. Standby Mode:

    -Running: External Crystal Clock Oscillator

   -Wakeup: Watchdog-module, external interrupt , up time is       higher than power-down mode

What is Power Domain ?

1. Power-Up & Power-Down Sequence : 

The power up sequence is the sequence in which the power is tuned on for the entire chip. The power down sequence is the sequence in which the power is shut down of the entire chip. This includes specifications of the time intervals between several steps in the mentioned sequence(s). A power sequence is used when there are Semiconductor Devices with different power supply voltages (a.k.a Power Domains) mixed together on one board/chip. The time interval specifications differ depending on the device, which can cause problems when applying power to on-board devices with different power supplies. In a general power sequence, power to the main block is applied first, followed by the peripheral blocks. The reverse occurs for power shutdown.

Summary:

Power-Modes Manages the power supply of various Power-Domains. According to a Specific Power-Mode , the Power Management Block Distributes Power to the Various Power Domains. Power Mode - is a Specification of POWERING/DE-POWRING Operation. Power Domain - is a Circuit Block with Specific Power Need.

Watch the video lecture here:

Also can watch all the episodes together:

Courtesy: Image by www.pngegg.com

Read More

Digital-Buffer vs Logic Level Shifter: UPF Episode - 6

This episode of the UPF in VLSI Series aims to answer the question posed by one of our viewer in the third episode. The episode covers a range of topics, beginning with an introduction to digital buffers and the different types available. The concept of a level shifter, also known as a translator, is then explored, including the various types available. Viewers are then provided with a comparison of buffers and level shifters, including an example to help illustrate the differences between the two. The episode concludes with a summary of the key differences between the two components, with a focus on the SN74LV1T34 logic level shifter.

What is a Digital Buffer ?

A digital buffer a.k.a. voltage buffer, provides either "no voltage" or "a output voltage that is same as the input voltage". It draws very little current and will not disturb the original circuitry. To do this, a voltage buffer is constituted with a very high input impedance. As a consequence , the power source will not be affected. It is also called a unity gain buffer because it provides a gain of 1 hence serving no amplification factor. A Digital Buffer is widely used for Registers. A typical Digital Buffer that is used to control multiple data inputs written onto a bus is a Tri-State Digital Buffer, which controls the data flow by "tri- state" pins. 

Types of Digital Buffers:

Inverting Buffer : This kind of buffer produces the state opposite to the input. If the input is high, the output is low and vice versa. Graphically, it is often represented as a triangle with a small circle attaching to the tip.

Non-Inverting Buffer : This kind of buffer performs no inversion or decision-making possibilities. A single input digital buffer is different from an inverter. It does not invert or alter its input signal in any way. In other words, Output will be high if and only if Input is HIGH. 

Tri-State Digital Buffer : Tri-state digital buffer has two inputs: a data input and a control input. A control works like a valve which controls the data flow. When the control input is active, the output value is the input value.

Active High Tri-State Digital Buffer : An active high tri-state digital buffer is a buffer with control input high as an active state.ONLY when the control input is 1, data transmission occurs.

What is a Level Shifter (a.k.a Translator) ?

A level shifter (a.k.a voltage level translator or logic-level shifter ), in digital electronics, is a circuit used to translate signals from one logic level or voltage domain (VDD/VSS) to another. It allows compatibility between different sub-chip blocks of ICs with different voltage requirements, such as TTL and CMOS. Modern systems use level shifters to bridge domains between processors, logic, sensors, and other circuits. In VLSI most common logic levels have been 1.8V, 3.3V, and 5V. However levels above and below these voltages are also used.

Types of Level Shifters:

Uni-Directional – All input pins are dedicated to one voltage domain, all output pins are dedicated to the other. Bi-Directional with Dedicated Ports – Each voltage domain has both input and output pins, but the data direction of a pin does not change. Bi-Directional with External Direction Indicator – When an external signal is changed, inputs become outputs and vice versa. Bi-Directional with Auto-Sensing – A pair of I/O spanning voltage domains can act as either inputs or outputs depending on external stimulus without the need for a dedicated direction control pin.

Buffer Vs Level Shifter : Comparison

The job of a buffer is to replicate a digital signal and also increase its drive strength to being degraded by other circuitry. As an example , a buffer take the signal from the microcontroller and reproduce it. Unlike the microcontroller, the buffer has a higher tolerance for being loaded down. At he same time the buffer will provide more steady output the with correct voltage for even with fast transition times. A level shifter is similar to a buffer in that it replicates signals and is drive strength is tolerant to being loaded down. However, it contains an additional feature to convert logic levels to to correct voltage value among different Voltage Domains.

Buffer Vs Level Shifter : Example

A micro-controller will use 0v and 3.3v for logic 0 & 1 levels, whereas something you want to connect which will use 0v and 5v instead. What happens when you connect the two? The micro-controller will try to communicate with the external circuit. It will send a 0 at 0v, and the external circuit will recognize the 0v as logic 0. Everything is fine so far. However, when the micro-controller sends a logic 1 at 3.3v, the external circuit may not recognize that as logic 1 since it expects logic 1 to be 5v. A level shifter comes into the picture in this situation. Now we replace the buffer with a level shifter. When the micro-controller outputs logic 0 at 0v, the level shifter will output 0v. When the micro-controller outputs logic 1 at 3.3v, the level shifter will convert 3.3v signal to  5v signal instead. The external circuit sees 0v and 5v and everything works out.

SN74LV1T34 : Logic Level Shifter

Single-Supply Voltage Translator at 5V, 3.3V, 2.5V, 1.8V VCC

Operating Range : 1.65V to 5.5V

Up Translation :

1.2V to 1.8V at 1.8V VCC

1.5V to 2.5V at 2.5V VCC

1.8V to 3.3V at 3.3V VCC

3.3V to 5.0V at 5.0V VCC

Down Translation

3.3V to 1.8V at 1.8V VCC

3.3V to 2.5V at 2.5V VCC

5V to 3.3V at 3.3V VCC

Output Drive

8mA Output Drive at 5.0V

7mA Output Drive at 3.3V

3mA Output Drive at 1.8V

Buffer Vs Level Shifter : Summary

In a nutshell a buffer tries to recreate the input signal as exactly as possible whereas a level shifter looks to alter the signal acting like a language interpreter. A buffer is just an amplifier. It takes a signal and puts out a low- impedance version of the signal. There may or may not be any actual voltage amplification. A a level shifter will translate between different standards of logic 1 & 0 of separate voltage domains.

Watch the video lecture here:

Also can watch all the episodes together:

Courtesy: image by www.pngegg.com

Read More

Exploring the Importance of Makefile in VLSI Design: A Comprehensive Guide

In this informative article, we delved into various important topics related to VLSI design. The primary focus was on unraveling the concept of makefile/makeflow and its significance within the VLSI domain. This article and video is created in response to a request made by one of our viewers, Deepak Singh Yadav, who specifically asked for a tutorial on how to create makefile or makeflow in VLSI, which emerged from a comment he left on our BASH/AWK video. The episode further provided a simplified explanation of HDL (Hardware Description Language) and explored the three key stages in HDL Simulation & Verification : compilation, elaboration, and simulation. Additionally, the video highlighted the essential role of makefile automation in streamlining and optimizing the VLSI design process.

Lets Understand HDL : Simple Way

1. What is HDL :  

Hardware Description Languages (HDLs) like Verilog, VHDL, or SystemVerilog are text-based files that describe hardware behavior and structure. They may resemble software code, but they’re fundamentally designed for hardware operations.

2. C Code vs. HDL Code: While C programming defines software operations, HDL defines hardware operations.

3.Top-Level Design Approach: Digital designs often follow a hierarchical top-down approach. The top module, typically named top.v or top.vhdl, serves as the entry point for simulation and synthesis.

3. Verification and Testbenches:

Before converting a design into hardware, it must be verified. A testbench applies input vectors to the Design Under Test (DUT) and checks its output. This ensures functionality at a basic level.

In VLSI the HDL code must go through three consecutive stages compilation, elaboration and simulation.

Compilation:

RTL and testbench files are text files that must be analyzed before simulation. A parser tool reads every HDL file and checks for correct syntax. Each language has a language reference manual (LRM) that defines valid syntax. Different versions of HDL languages may have different LRM requirements. The compiler checks for syntax errors and reports warnings and errors. Before elaboration, all files, including RTL and behavioural, must be syntactically correct. Industrial designs often integrate legacy HDL code, which may follow older LRM standards. Only syntax-correct files progress to the next stage. Any errors must be resolved before moving forward.

Elaboration:

All HDL source files are checked for syntax errors, but a design is a group of files that connect in a specific way. If module M and module N have different widths for an array of bits that connect, the elaboration tool will report an error. It doesn't make sense to connect an array of 8 bits to an array of 6 bits. The tool could connect them and leave an extra or unconnected bit, but that's an arbitrary choice and would not make sense in the design. A design is correct only if the connections are correct in width and direction. Elaboration checks if the design and test bench are consistent and connected correctly. Elaboration consists of 

Module Flattening: Large designs often include multiple interconnected modules. During elaboration, these connections are "flattened" into a unified structure.

Error Detection: Issues such as mismatched bus widths or direction mismatches are flagged at this stage. For example, connecting an 8-bit array to a 6-bit array would generate an error.

Linking Libraries: This stage links object files to libraries, creating an executable program for the next step.

Successful elaboration produces an executable binary, ready for simulation.

Simulation:

The executable binary created in elaboration stage is run at this stage. This binary in turn invokes the simulator and the waveform viewer. A simulator process the testbench code that applies stimulus to the RTL design and produces the result through a waveform viewer. A waveform viewer shows the signals in the design and testbench over time. For example, an adder that adds two integers together can have its input and output visualized in a waveform viewer. 

Makefile Automation: The Game-Changer

Now that we’ve covered the three steps, let’s see how Makefiles simplify the process.

What is a Makefile?

A Makefile is a text file that automates repetitive tasks in the HDL workflow. It coordinates compilation, elaboration, and simulation with minimal manual intervention.

Key Benefits of Makefiles:

1. Streamlined Setup:

Makefiles manage environment variables, tool paths, and license dependencies. This eliminates the need for manual configuration.

2.Selective Compilation:

In large designs with thousands of files, Makefiles identify and recompile only the modified files. This saves time and prevents unnecessary rework.

3. Output Management:

Makefiles specify where simulation results, waveforms, and log files are saved, maintaining an organized workflow.

4. Error Minimization:

By automating the process, Makefiles reduce the chances of human error during design and verification.

Why Makefiles Matter? 

In frontend VLSI, managing hundreds or thousands of HDL files can be overwhelming. 

Makefiles bring order to this chaos by -

1. automating the three-stage process of compilation, elaboration, and simulation.

2. tracking changes and optimizing resource usage.

3. ensuring consistency and reliability across complex workflows.

By leveraging Makefiles, engineers can focus on design and innovation rather than manual setup and troubleshooting.

Conclusion:

The Makefile is more than a tool—it’s a cornerstone of efficient VLSI design workflows. It ensures accuracy, saves time, and simplifies the entire process from compilation to simulation. Whether you're an RTL designer or a verification engineer, mastering Makefile automation is key to staying ahead in the field.

If you found this blog helpful, don’t forget to share it with your peers. Happy designing!

Watch the video lecture here:

Courtesy: Image by www.pngegg.com

Read More

Choosing the Right Laptop or Desktop for Semiconductor Aspirants: A Comprehensive Guide

 

This article covers an array of essential topics related to VLSI design, catering specifically to beginners. It starts with a detailed discussion on the ideal laptop or desktop configuration for someone who is just starting in VLSI design. The article then proceeds with an introduction to the field and its significance in modern technology, followed by an exploration of LINUX and Virtual Box, which are popular tools . Additionally, the article examines the various scripting languages that are commonly used in VLSI design, such as Verilog and SPICE, and their applications. Finally, the importance of Timing Tool in VLSI design is also covered in detail.

Are you a semiconductor aspirant or a fresher wondering about the ideal desktop or laptop configuration? If yes, you're in the right place! For anyone planning a career in the semiconductor industry, having the right tools is essential. This blog will walk you through everything you need to know about system requirements, so you can confidently set up your learning environment.

Why Do You Need the Right Setup?

Before stepping into the semiconductor field, you must master certain key topics such as:
- Linux
- Scripting languages (Perl, TCL, Python)
- Hardware description languages (Verilog, VHDL)
- SPICE simulation tools
- Timing analysis tools These skills require hands-on practice, which means your computer must support various tools and software efficiently. Let’s break it down step by step. Essential Skills and the Tools You'll Use 1. Linux :
Linux is the backbone of the semiconductor world. Most laptops and desktops come with Windows pre-installed, but you’ll need Linux for practical learning. The easiest way to start is by installing Linux on a virtual machine (VM) using VirtualBox.

VirtualBox Compatibility:
- Runs on Intel and AMD processors.
- Supports multiple OS environments like Windows, Linux, macOS, and more. System Requirements for VirtualBox:
- Processor: A multi-core processor with virtualization technology (4 cores minimum; 8 cores recommended).
- RAM: 4GB minimum (8GB recommended for one VM; 16GB for multiple VMs).
- Storage: 20GB per VM minimum (50GB recommended).
- SSD: For faster OS and software performance, opt for an SSD from the start. 2. Scripting Languages :
Proficiency in scripting languages like Perl, TCL, Python, and Shell is crucial for VLSI professionals. These languages form the communication layer between you and the tools you'll use. System Requirements:
These languages are light on resources and run smoothly on basic configurations. You can install interpreters like Python on any OS, including Windows and Linux. 3. Verilog and VHDL:
Learning hardware description languages (HDLs) like Verilog and VHDL is essential, whether you're heading toward front-end or back-end design. Recommended Tools:
- Vivado (by Xilinx): A robust tool, though resource-intensive.
- Icarus Verilog: A lightweight simulator for Verilog. System Recommendations for Vivado:
- 8GB RAM minimum.
- SSD for smoother performance. 4. SPICE Simulators:
Simulation tools like PSpice and LTSpice are invaluable for circuit design. These tools are not resource-heavy, so the configuration suitable for VirtualBox will suffice. 5. Timing Analysis Tools :
For timing analysis, OpenTimer is a great free tool. Like SPICE simulators, it is not demanding on system resources, so the VirtualBox configuration will handle it well. General System Configuration Recommendations If you’re purchasing or upgrading a system, consider the following specs to future-proof your setup:
1.CPU: Latest generation Intel or AMD processor with virtualization support.
2. RAM: At least 8GB (16GB recommended for heavy multitasking).
3. Storage: 500GB SSD (minimum).
4. GPU: An entry-level graphics card is optional but recommended for upcoming VLSI tools that utilize GPU cores alongside CPU cores. 6. Free Tools to Get Started :
There are plenty of free tools available to kick-start your journey in VLSI design. We’ve created detailed video tutorials on these tools, including their installation and usage. Check the links in the video description to learn more. 7. Final Thoughts :
Setting up the right system is an investment in your career as a semiconductor professional. With the recommended configurations, you’ll have a system that supports your learning and preparation for the VLSI domain. If you have questions or need further guidance, drop your comments below. Don’t forget to explore our other videos for detailed insights into front-end vs. back-end design, tool tutorials, and more.

Watch the video lecture here:

Courtesy: Image by www.pngegg.com

Read More