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Computer Organisation and Architecture - Vol 3
Explore and master the fundamentals of Computer Organisation and Architecture - Vol 3
You've not yet enrolled in this course. Please enroll for free to listen to audio lessons, classroom podcasts and take practice test.Chapter 1
Memory System
The chapter covers the fundamentals of memory systems, detailing classifications, performance parameters, and types of memory including volatile and non-volatile options. It explains the hierarchical organization of memory, which includes registers, cache, and primary storage. Key concepts like access time, unit of transfer, and various memory technologies are also introduced, alongside characteristics that influence the choice of memory types for different applications.
Chapter 2
Basics of Memory and Cache Part 2
Memory technologies vary significantly in access times and costs. The hierarchy of memory, from registers to magnetic disks, balances speed and cost, optimizing performance while managing budget constraints. Understanding locality of reference is key to designing effective memory hierarchies, allowing for efficient data retrieval and storage.
Chapter 3
Direct Mapped Cache Organization
The chapter covers the organization and operation of direct-mapped caches, including cache lines, tag fields, cache hits, and misses. It provides practical examples illustrating how memory addresses map to cache lines and how data is retrieved from memory. The significance of utilizing fast cache memory to reduce execution time by exploiting local reference patterns is emphasized.
Chapter 4
Direct-mapped Caches: Misses, Writes and Performance
This chapter discusses memory hierarchy and the role of cache memory in optimizing performance in computer systems. It highlights the differences between various memory types, emphasizing the speed, cost, and access times associated with SRAM, DRAM, and magnetic disks. Additionally, it describes the principle of locality of reference and how it helps in organizing memory efficiently, culminating in an explanation of cache memory's design and operation.
Chapter 5
Direct Mapped Cache Organization
The chapter focuses on the organization and function of direct mapped cache in computer memory systems. It discusses how memory addresses are structured, cache hits and misses, and how data is retrieved from cache versus main memory. Various examples illustrate how data is managed within a direct mapped cache, providing insight into both theoretical and practical aspects of cache operation.
Chapter 6
Associative and Multi-level Caches
The chapter discusses cache memory and how its organization affects performance, particularly focusing on associative and multi-level caches. It highlights the differences between direct-mapped, fully associative, and set-associative caching strategies, explaining their respective strengths and weaknesses in terms of cache miss rates. Furthermore, the chapter describes the importance of a block replacement policy for effective cache management.
Chapter 7
Multi-level Caches
The chapter discusses multi-level cache architectures, focusing on the role of primary and secondary caches in enhancing CPU performance. It explains the concepts of cache hits, misses, and penalties, along with the effective cycles per instruction (CPI). Furthermore, it presents examples showcasing the calculations involved in cache operations and design considerations, emphasizing the impact of cache organization on performance.
Chapter 8
Lecture – 28
This chapter focuses on the architecture and organization of computer memory systems, including the importance of various memory types such as SRAM, DRAM, and magnetic disks. It discusses the trade-offs between speed, cost, and size of memory, emphasizing the necessity of hierarchical memory structures to optimize performance and access times. The chapter also delves into cache memory, its mapping techniques, and the use of multi-level caches to enhance overall system efficiency.
Chapter 9
Basics of Virtual Memory and Address Translation
Virtual memory is a technique that allows multiple processes to concurrently reside in main memory, providing the illusion of a large addressable space even with limited physical memory. It enables efficient management by mapping virtual addresses to physical addresses, enforcing protection between programs and the kernel. This translation process supports operations like page sharing and eliminates the need for contiguous memory allocation, thus simplifying the memory management processes.
Chapter 10
Page Faults in Virtual Memory
This chapter delves into the functioning of virtual memory, specifically focusing on page faults and their management. It discusses the importance of page size in optimizing access time to memory and how page tables facilitate the mapping of virtual addresses to physical addresses. Additionally, the chapter covers various memory management techniques, including associative mapping and page replacement algorithms, to enhance the efficiency of memory access.
Chapter 11
Lecture – 28: Paging and Segmentation
The chapter discusses the mechanisms of virtual memory management, specifically focusing on paging and segmentation. It explains how virtual addresses are converted to physical addresses through page tables, detailing the structure and size of these tables in modern computing systems. Additionally, it explores the use of page table length registers and the dual-segment model to efficiently manage virtual memory for processes that grow dynamically over time.
Chapter 12
Hierarchical Page Tables
Hierarchical page tables are introduced as an optimal solution for page table management, helping to efficiently allocate memory for processes. The transition from single to multi-level page tables is essential for efficiently managing large addresses, particularly in 64-bit systems. Further techniques like hashed and inverted page tables are examined as advanced methods to minimize memory usage and enhance performance.
Chapter 13
TLBs and Page Fault Handling
The chapter explores the challenges of managing page tables in computer systems, particularly regarding address translation speed and memory access efficiency. It discusses the implementation of page tables in hardware and the use of Translation Lookaside Buffers (TLBs) as a solution to minimize costly memory accesses. Furthermore, the chapter details the caching mechanism of TLBs, the handling of page faults, and the performance implications of these strategies on system operations.
Chapter 14
Page Faults
This chapter examines the intricacies of page faults and the functioning of memory hierarchies in computer architecture. It explores the mechanisms behind page fault handling, including the processes involved in mapping virtual addresses to physical memory. Additionally, it discusses the roles of translation lookaside buffers (TLBs) and cache systems in enhancing memory access speeds while managing physical and virtual memory interactions.
Chapter 15
Cache Indexing and Tagging Variations, Demand Paging
The chapter discusses various cache indexing and tagging variations, primarily focusing on demand paging and virtual memory management techniques. It outlines the operational differences between physically indexed and virtually indexed caches and highlights the challenges associated with each method, such as TLB misses and synonym problems. Various strategies, including page coloring, are introduced to mitigate issues such as data inconsistency and cache flushing during context switches.
Chapter 16
Performance Factor of Paging and Caching
The chapter focuses on CPU performance factors, particularly in relation to paging and memory access times. Key concepts include calculating CPU time, miss rates, and the implications of page faults in context to memory access. It introduces page replacement algorithms and discusses their importance in maintaining low page fault rates to optimize overall system performance.
Chapter 17
FIFO Page Replacement
The chapter covers various page replacement algorithms used in operating systems, emphasizing the mechanics and effectiveness of FIFO, Optimal, and LRU strategies. It addresses the challenges and solutions surrounding these algorithms, particularly in tracking page usage to minimize page faults. It also discusses approximation techniques for LRU and introduces the modified clock replacement algorithm, highlighting their practical applications and limitations.
Chapter 18
Page Replacement Algorithms
The chapter extensively explores the design and management of cache memory, focusing on virtually indexed and physically tagged cache mechanisms, along with various page replacement strategies. It highlights the trade-offs involved in cache indexing methods, such as issues with cold misses during context switches and the synonym problem in set-associative caches. The chapter also delves into efficient page replacement algorithms, using examples like FIFO and LRU while addressing practical challenges in their implementation.
Chapter 19
Approximate LRU Implementation
This chapter delves into various page replacement algorithms used in memory management, highlighting the limitations of exact LRU and introducing approximate LRU methods such as reference bits and sampled LRU. It discusses the clock algorithm and second chance strategies while also addressing Belady's anomaly, which challenges conventional expectations regarding page fault occurrences with increased memory frames. The chapter emphasizes the importance of efficiently managing memory references to optimize system performance.
Chapter 20
Belady's Anomaly
The discussion centers around page replacement strategies in memory management, particularly exploring Belady’s anomaly, which occurs when an increased number of page frames leads to more page faults. Key algorithms such as LRU (Least Recently Used) and optimal algorithms are presented, highlighting their inability to exhibit Belady’s anomaly as they adaptively manage recently accessed pages. The chapter further delves into memory allocation strategies for processes and addresses concepts like page buffering and thrashing.
Chapter 21
Page Frame Allocation and Thrashing
The chapter focuses on paging, specifically discussing frame allocation strategies and the problems associated with thrashing. It elaborates on different allocation schemes such as fixed and proportional allocation, and how priority-based allocation can impact performance. Additionally, it introduces the concept of thrashing, its causes, and the working set model to manage memory effectively.
Chapter 22
Summary of Memory Sub-system Organization
The chapter discusses virtual memory as a crucial component of the memory hierarchy, managing the interface between the main memory and disk. It emphasizes the mechanisms of address translation, the importance of page tables, and methods to optimize memory access while preventing thrashing. Techniques such as using large page sizes, efficient page replacement algorithms, and minimizing page faults through TLB caching are highlighted.
Chapter 23
Input-Output Primitives
This chapter addresses the architecture of Input-Output (I/O) modules, emphasizing their crucial role in enabling communication between peripheral devices and the CPU. It reviews the structure, functions, and design methodologies of various I/O operation modes, including programmed I/O, interrupt-driven I/O, and direct memory access (DMA). The chapter also discusses addressing schemes for I/O devices and the necessity of device controllers to manage these devices effectively.
Chapter 24
External Devices and Their Types
The chapter discusses various input/output (I/O) devices and modules, explaining their roles in computer systems, including human-readable and machine-readable devices. It further elaborates on the memory hierarchy, the function of the I/O module, and different methods of data transfer such as programmed I/O, interrupt-driven I/O, and direct memory access (DMA). Additionally, it highlights the importance of error detection and synchronization in device communication.
Chapter 25
Programmed I/O Overview
The chapter discusses the intricacies of Input/Output (I/O) operations, focusing on programmed I/O techniques and the necessity of I/O modules. It outlines the requirements for I/O commands, addressing schemes, and the distinction between memory-mapped I/O and isolated I/O. The significance of I/O modules is emphasized due to their need for managing diverse devices without directly connecting them to the CPU.
Chapter 26
Lecture – 34
This chapter elaborates on the concept of interrupt-driven I/O in computer organization, detailing its necessity over programmed I/O. It explains the sequence of events that occur during interrupt processing, emphasizing the importance of context switching, interrupt service routines, and the handling of processor states during interruptions. The chapter concludes with a focus on the advantages of interrupt-driven systems in enhancing CPU efficiency and reducing idle time.
Chapter 27
Interrupts and Processor Management
The chapter discusses the concepts of interrupts in CPU processes, focusing on how devices can signal the processor to gain attention through interrupt requests. It details the mechanisms for enabling and disabling interrupts, the implications of interrupt servicing, and the design considerations for handling multiple interrupts and prioritizing tasks.
Chapter 28
Lecture – 35
DMA (Direct Memory Access) transfer allows hardware devices to transfer data directly to and from memory without involving the CPU, thereby freeing up the processor for other tasks. This chapter discusses the need for DMA, its operational principles, and how it alleviates processor workload compared to programmed and interrupt-driven I/O. Additionally, it covers design considerations for effective DMA controller implementation.
Chapter 29
Overview of DMA and Interrupt Driven I/O
The chapter addresses the concepts and mechanisms of Direct Memory Access (DMA) and its differences from traditional interrupt-driven I/O. It discusses how DMA allows for data transfer directly between peripherals and memory, reducing CPU involvement and improving efficiency. Various transfer modes such as burst transfer and cycle stealing are explained, showcasing the flexibility and challenges of DMA operations.
Chapter 30
Storage Devices
The chapter discusses the various types of storage devices essential for secondary memory in computer architecture, emphasizing the functionality and design issues associated with hard disks. It explains the importance of hard disk controllers and outlines the memory hierarchy, highlighting the differences in speed, capacity, and cost among primary and secondary memory types. Moreover, it provides insights into data organization and the read/write mechanisms of magnetic disks.
Chapter 31
Disk Characteristics
The chapter discusses the characteristics and mechanisms of disks, including the differences between fixed and removable disks, as well as single and multiple platter setups. It explains key concepts such as angular velocity, seek time, rotational delay, and access time, relevant to understanding how data is stored and retrieved from disk drives. The chapter emphasizes the importance of addressing formats and transfer rates in optimizing disk performance.
Chapter 32
Working Principle of Hard Disk
The chapter covers the fundamental aspects of input/output systems, focusing on the operation and organization of hard disks as both input and output devices. Key elements include the function of device drivers, the principles of data transfer, organization of data on disks, and performance measurement criteria. Additionally, it outlines the different modes of I/O transfer and the need for I/O modules in connecting peripheral devices to processors.