Cache Hit, Cache Miss & Mapping Type
Duration: 5 min
This video lesson is available to enrolled students.
Inside: a video lesson and guided study material.
Module outline
- Section A | English: Vocabulary, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Preposition, Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Articles, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Verbal Analogy (Word Based Analogy)
- Section A | Quant Aptitude: Ratio and Proportion (Ratios), Mixture and Alligation, Permutation and Combination, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Arithmetic, Algebra, Powers and Exponents (Surds and Indices), Average, Age Problems, Percentage, Profit and Loss, Partnership, Time and Work, Simple Interest and Compound Interest, Mensuration and Geometry, Probability, Pipe and Cistern
- Section A | Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Calendar, Clock, Blood Relations, Directions (Direction Test), Seating Arrangements, Ranking, Order and Sequence, Puzzle Solving (Puzzles)
- Section B | C Programming: C Programming by Yash Sir, Coding Questions by Yash Sir
- Section B | Data Structures: Algorithm Analysis, Greedy Algorithms, Time Complexity Analysis, Sorting Algorithms, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs
- Section B | OOP (C++): Object Oriented Programming (OOPS), Programming in C++
- Section B | OS: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS
- Section B | Networking: Introduction to CN, Data Communication, 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
- Section B | AI & Big Data Basics: AI & ML by Arun Sir, Big Data Systems
- Section C | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Analog-Digital Conversion
- Section A, C | Comp. Fundamentals, COA: Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations, Multiprocessors, Programming the Basic Computer
- MOCK TEST:
AI summary & chapters
AI Summary
An AI-generated summary of this video lecture.
The lecture introduces cache memory performance metrics, defining cache hits, misses, and their associated latencies. It visualizes the memory hierarchy from CPU to secondary storage and explains the mapping process where main memory blocks transform into cache lines. The session concludes by listing three mapping techniques and a table of decimal versus binary memory prefixes.
Chapters
0:00 – 2:00 00:00-02:00
The instructor defines 'Cache Hit' as the scenario where the CPU finds the requested word in the cache memory, noting that performance is frequently measured by the 'hit ratio.' He introduces 'Hit Latency' as the time required to match data into cache memory. Visually, a diagram illustrates the flow from CPU to Cache Memory, then to Main Memory (labeled Physical/Primary Memory/RAM), and finally to Secondary Memory (labeled Logical/Virtual/Auxiliary Memory). The instructor annotates the diagram with 'CoA' (Control Address) and 'OS' (Operating System) to indicate control signals and software interactions between these memory levels. He underlines key phrases like 'frequently measured in terms of a quantity called hit ratio' and 'finds the word in cache' to emphasize definitions.
2:00 – 5:00 02:00-05:00
The lecture transitions to 'Cache Miss,' defined as the event where the word is not found in cache but resides in main memory. 'Miss Latency' is explained as the time needed to retrieve data from main memory to cache. The instructor emphasizes that a high hit ratio keeps average access time close to the fast cache memory speed. He then introduces the concept of 'mapping,' the transformation of data from main memory to cache. He visually represents memory units as 'Lines' (Cache), 'Blocks' (Main Memory), and 'Pages' (Secondary Memory). Finally, he lists the three types of mapping procedures: Direct mapping, Associative mapping, and Set-associative mapping, marking them with red checkmarks to signify the core classification methods.
5:00 – 5:17 05:00-05:17
The instructor displays a table comparing decimal prefixes (10^3, 10^6, 10^9, 10^12, 10^15) with their binary counterparts (2^10, 2^20, 2^30, 2^40, 2^50). The table lists terms like '1 Thousand,' '1 kilo,' '1 Million,' '1 Mega,' '1 Billion,' '1 Giga,' '1 Trillion,' '1 Tera,' and '1 Peta.' This section appears to be setting up a discussion on memory size calculations or addressing schemes, likely to follow the mapping discussion, providing the necessary numerical context for memory capacity.
The video provides a foundational overview of cache memory systems. It begins by establishing performance metrics like hit ratio and latency, distinguishing between successful data retrieval (hit) and the penalty of fetching from slower memory (miss). The instructor uses a hierarchical diagram to visualize the relationship between CPU, cache, main, and secondary memory. The lesson progresses to the structural organization of data, defining how main memory blocks map to cache lines. It concludes by introducing the three standard mapping techniques and a reference table for memory prefixes, preparing the viewer for calculations involving memory capacity and addressing.