Category: DHD

Digital Hardware Design

Basic Verilog Questions for Beginners (Part – 1) : Build Your Foundations

June 24, 2025December 13, 2025 vlsifacts No Comments

1. What is Verilog and why is it used in VLSI design? Verilog is a Hardware Description Language (HDL) widely used to design and model digital electronic systems. It helps in writing structured, reusable code to describe how a circuit should function. Verilog is crucial in VLSI design because it supports simulation, verification, and hardware…

Interview, Question Bank, Verilog

Is an “initial” Block Synthesizable in Verilog?

June 20, 2025December 13, 2025 vlsifacts No Comments

When working with Verilog for digital design, one common question that arises is whether the initial block is synthesizable. The short answer is generally no. initial blocks are primarily meant for simulation and testbench purposes, not for actual hardware synthesis. What is an initial Block? The initial block in Verilog is used to set initial values for signals or variables at the very…

Verilog

Logic Levels in Digital Circuits

March 20, 2023June 19, 2025 vlsifacts No Comments

In digital systems, any signal value is represented in binary form (either logic ‘0’ state or logic ‘1’ state). To represent these two logic states, two different levels of voltage or two different levels of current are considered. Here, we will consider voltage for understanding. You can also consider current in the same way. If…

Digital Electronics

Hamming Codes

March 20, 2023June 19, 2025 vlsifacts No Comments

Hamming Code is yet another error detection and correction code. In this code, the parity bits are added to increase the Hamming distance between the valid code words. Here, the parity bits are arranged in a way that different error bits produce different error results. This enables the Hamming Code to both detect and localize…

What are Code Words in case of Error Detection and Correction

March 20, 2023June 19, 2025 vlsifacts No Comments

A system that uses error-detecting code generates, transmits, and stores data in the form of code words. So, the correct data must be a valid code word. It is expected that the presence of an error in a data bit stream would make it a non code word, and thereby it would be easy to…

Digital Electronics

Hamming Distance

March 19, 2023June 19, 2025 vlsifacts No Comments

Hamming distance between two bit-strings of equal length is the number of bit positions at which they are different. In other words, Hamming distance is the number of mismatches at the same bit position between two same-length words. For example: Consider two 3-bit code words, 000 and 001. Here, the Hamming distance is 1, as…

Parity Code for Error Detection

March 18, 2023June 19, 2025 vlsifacts No Comments

One of the most common ways to achieve error detection is by means of parity code. A parity code is generated by adding an extra parity bit (information redundancy) to the string of data bits. There are two types of parity, such as even parity and odd parity. A given system operates with either even…

Digital Electronics

Error Detection and Correction Codes

March 18, 2023June 19, 2025 vlsifacts No Comments

Data errors in a digital system can happen due to faults in the transceiver system or noise during the transmission. Such errors need to be detected and corrected, as digital systems are sensitive to such errors. The presence of data errors beyond a threshold can lead to catastrophic situations if not taken care of immediately….

Digital Electronics

Applications of Gray Code

March 18, 2023June 19, 2025 vlsifacts No Comments

Gray code is considered beneficial for multiple electromechanical applications due to its error resilience property. This is achieved due to the single-bit change from one code word to the adjacent next code word. This article lists down a few more applications of Gray code. Reference: Maini, Anil K. Digital electronics: principles, devices and applications. John…

Read More “Applications of Gray Code” »

Digital Electronics

Binary to Gray Code Conversion and Vice Versa

March 18, 2023June 19, 2025 vlsifacts No Comments

In this article, we will learn about the conversion of binary to Gray code and vice versa. You can refer to the gray code table, where we have already shown the gray codes of 3-bit numbers, that is, the decimal numbers from 0 to 7. In this article, we will learn the conversion techniques so…

Digital Electronics