Cyclic Redundancy Check Part-1

Duration: 8 min

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Module outline

  1. General Intelligence & Reasoning: Analogy, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Logical Sequence Of Words, Syllogisms, Venn Diagram, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Data Sufficiency, Puzzle Solving (Puzzles), Data Arrangement, Cubes & Dices, Calendar, Clock, Arithmetic, Number System, HCF LCM, Verbal Analogy (Word Based Analogy), Visual Recognition and Figure Completion, Paper Folding and Cutting, Transformation of Shapes, Clocks and Calendars, Direction Sense, Cubes and Dice, Patterns in Two-Dimensional Figures, Seating Arrangements, Analogy and Classification, Logical Deduction and Induction, Alphabet and Word Tests, Mathematical Operations, Series Completion, Simplification and Approximation, Coding and Decoding, Numerical Reasoning, Assembling and Grouping of Shapes, Three-Dimensional Patterns and Visualization, Vocabulary, Number System, Averages, Mixtures and Alligation, Simple and Compound Interest, Percentages, Algebra, Speed, Time and Distance, Seating and Arrangement Puzzles, Traverse Surveying, Order, Ranking and Sequence, Constraint Puzzles, Syllogisms and Venn Diagrams, Reading Comprehension, Critical Reasoning, Permutations and Combinations, Narrative Sequencing, Project Monitoring, Resources and Safety, Profit, Loss and Discount, Ratio and Proportion, Time and Work, Mensuration, Data Interpretation, Powers, Surds and Logarithms, Sequences and Series, Articles and Determiners, Sentence Completion, Data Sufficiency, Blood Relations, Simple Interest and Compound Interest, Mixture and Alligation, Sequence and Series (Series), Speed Time and Distance, Algebra, Profit and Loss, Powers and Exponents (Surds and Indices), Permutation and Combination
  2. General Awareness: Physics, Chemistry, Biology, History, Geography, Polity, Indian Economy, Environment, Static General Knowledge, GK- Current Affairs, Artificial Intelligence, MS Office Applications, Terms & Abbreviations, Keyboard Shortcuts, Evolution of Indian Banking (Banking & Financial Awareness), Emerging Tech Trends
  3. Engineering Mathematics: Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic, Linear Algebra, Calculus, Probability, Statistics, Signal Space and Optimum Detection, Probability, Statistics
  4. Digital Logic: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Floating Point Rep, Number Systems and Codes, Registers and Counters, Boolean Algebra and Logic Gates, Microprocessors and Microcontrollers, Logic Families and CMOS Logic, Microprocessors, Logic Gates and Boolean Algebra, Minimization of Boolean Functions, Timing, Hazards and Testing, Logic Families, Combinational Logic Design, Arithmetic Circuits, Waveform Generators and Timer Circuits, Semiconductor Memories and Programmable Logic Devices, Combinational Logic Circuits, Latches and Flip-Flops, Finite State Machines, Sequential Circuits and State Machines, Minimization of Boolean Functions, Arithmetic Circuits, Latches and Flip-Flops, Number Systems and Codes, Registers and Counters
  5. Computer Organisation & Architecture: Basics of COA, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Programming the Basic Computer, Register Transfer and Microoperations, Semiconductor Memories and Programmable Logic, Processor Organization and Instructions, Memory Hierarchy and Input/Output, Registers and Counters
  6. Programming & Data Structures: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, HTML Basics, OOPS with C++, Java, Object Oriented Technology
  7. Databases: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, Database Security & Authorization
  8. Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos
  9. Theory of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Complexity Theory
  10. Compiler Design: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization, Run Time Environment
  11. Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Security, Windows OS, Distributed Systems, Unix OS, Linux OS
  12. Computer Networks: Introduction to CN, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware Basics, Data Communication, Website, Browser & Services, Web Design & Development, Network Security, Cyber Threats and Malware Attacks, Cyber Safety and Security
  13. Full Length Mock Tests:
  14. Sectional Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This lecture introduces Cyclic Redundancy Check (CRC) as a method for error detection in data transmission, rooted in the properties of cyclic codes. The instructor begins by defining cyclic codes as a special class of linear block codes where any cyclic shift of a valid codeword results in another valid codeword. An illustrative example is provided: shifting the binary sequence 1011000 to the left yields 0110001, which remains a valid codeword. The lecture then transitions to the mechanics of CRC, explaining that a k-bit dataword is augmented by appending n-k zeros to its right-hand side. This augmented word serves as the dividend for a modulo-2 division operation using a predefined generator polynomial of size n-k+1. The remainder from this division becomes the CRC checksum, which is appended to the original dataword before transmission. The instructor demonstrates this process through detailed binary long division on a whiteboard, showing step-by-step subtraction and bit manipulation to derive the final remainder.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The session opens with a slide titled "CYCLIC CODES" defining them as linear block codes where cyclic shifts produce valid codewords. The instructor underlines the phrase "is another codeword" to emphasize this property and writes the number 10 on the display. The presentation then introduces Cyclic Redundancy Check, explaining that a k-bit dataword is augmented by appending n-k zeros. An example with k=4 and n=7 requires adding 3 zeros to create an n-bit result. Diagrams at the bottom visualize the sender's encoder and generator blocks alongside the receiver's checker components.

  2. 2:00 – 5:00 02:00-05:00

    The instructor moves to a whiteboard setup for binary long division with divisor 1011 and dividend 1001000. He explains the process while gesturing towards the numbers, writing intermediate binary values such as 011 beneath the dividend to demonstrate subtraction steps. The instructor performs a binary division operation for CRC, writing down the dividend and divisor, then subtracting binary values step-by-step. The process involves bringing down subsequent bits from the dividend to continue the division until a remainder is found, with on-screen text showing "1011" and "10010000".

  3. 5:00 – 8:09 05:00-08:09

    The instructor demonstrates CRC calculation using binary division, showing two separate examples on the whiteboard. He illustrates how to append zeros to a message and divide by a generator polynomial, highlighting specific bits during division steps. The instructor crosses out zeros and carries down subsequent bits to find the remainder, with on-screen text displaying "1011", "1010", "100110", and "106116". The demonstration emphasizes XOR operations and remainder generation, highlighting the final CRC checksum.

The lecture systematically builds understanding of Cyclic Redundancy Check by first establishing the theoretical foundation of cyclic codes and then applying it to practical error detection. The core concept is that cyclic codes maintain validity under rotation, which allows for efficient implementation using polynomial division. The instructor emphasizes the augmentation process where n-k zeros are appended to a k-bit dataword, transforming it into an (n)-bit dividend. This augmented word is divided by a generator polynomial of degree n-k using modulo-2 arithmetic, which behaves like XOR operations without carries. The remainder from this division constitutes the CRC checksum. Through whiteboard demonstrations, the instructor shows how to perform binary long division step-by-step, crossing out leading zeros and bringing down bits. The visual progression from definition to calculation helps students grasp how CRC detects errors by verifying that the received message is divisible by the generator polynomial without remainder.

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