CS 151: Memory System - Lecture 3a
46 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the correct term for a group of bits sized at 8, 16, 32, or 64 bits?

  • Byte
  • Block
  • Word (correct)
  • Nibble

    • In a little-endian system, the most significant byte is stored first in lower memory addresses.

    False (B)

    How many bits are required to address a memory space of 64 KB?

    16 bits

    In __________ byte ordering, the least significant byte is stored first.

    <p>little-endian</p> Signup and view all the answers

    Match the following terms with their descriptions:

    <p>Little Endian = Stores least significant byte first Big Endian = Stores most significant byte first Byte-addressable = Individual byte locations are addressed Word-addressable = Multi-byte words are indicated</p> Signup and view all the answers

    How many address inputs are needed to access 4KB of memory?

    <p>12 bits (C)</p> Signup and view all the answers

    The processor stores data in memory in the same sequence as it is inputted.

    <p>False (B)</p> Signup and view all the answers

    What is the hexadecimal representation of the binary value 0000 0101 0011 1001?

    <p>0529H</p> Signup and view all the answers

    Which of the following best describes the primary purpose of Random Access Memory (RAM)?

    <p>Store data and applications currently in use (A)</p> Signup and view all the answers

    Static RAM (SRAM) is faster than Dynamic RAM (DRAM).

    <p>True (A)</p> Signup and view all the answers

    What happens to the data stored in RAM when power is removed?

    <p>The data is lost.</p> Signup and view all the answers

    Auxiliary or external memory is also known as __________ memory.

    <p>secondary</p> Signup and view all the answers

    What type of memory allows for easy reading and writing by the microprocessor?

    <p>Random Access Memory (RAM) (D)</p> Signup and view all the answers

    Match the following memory types to their characteristics:

    <p>RAM = Volatile memory that can be read from and written to ROM = Non-volatile memory typically used for firmware SRAM = Faster speed and higher cost DRAM = Slower speed and lower cost than SRAM</p> Signup and view all the answers

    Main memory communicates directly with the CPU.

    <p>True (A)</p> Signup and view all the answers

    Name one example of auxiliary memory.

    <p>Hard disk, Magnetic tape, or Compact disk.</p> Signup and view all the answers

    What is the primary function of BIOS?

    <p>To tell the processor how to access resources (C)</p> Signup and view all the answers

    ROM is a type of volatile memory.

    <p>False (B)</p> Signup and view all the answers

    Explain why ROM is not suitable for regular data storage.

    <p>Programs and data in ROM cannot be changed or erased by regular program instructions.</p> Signup and view all the answers

    The type of ROM that can be erased using ultraviolet light is called _____ .

    <p>EPROM</p> Signup and view all the answers

    Match the following types of ROM with their descriptions:

    <p>Masked ROM = Manufactured with predefined data PROM = Can be programmed once EPROM = Erased by ultraviolet light EEPROM = Electrically erasable but slower to write</p> Signup and view all the answers

    Which type of memory is directly accessible by the CPU?

    <p>Internal memory (B)</p> Signup and view all the answers

    Data in RAM can be permanently stored without power.

    <p>False (B)</p> Signup and view all the answers

    What do static RAMs primarily use to store data?

    <p>D-latches (C)</p> Signup and view all the answers

    Dynamic RAMs are less expensive than static RAMs due to their simpler and smaller cells.

    <p>True (A)</p> Signup and view all the answers

    What are the main characteristics used to categorize memory systems?

    <p>Location, capacity, unit of transfer, access method, performance, physical type, and organization.</p> Signup and view all the answers

    What is the primary use of Read Only Memory (ROM) in a computer system?

    <p>To store the computer's BIOS</p> Signup and view all the answers

    A bit in a DRAM is stored using a device called a ______.

    <p>capacitor</p> Signup and view all the answers

    Which of the following statements is true about DRAM?

    <p>It requires periodic refreshing to maintain data. (D)</p> Signup and view all the answers

    Static RAM stores more data compared to Dynamic RAM.

    <p>False (B)</p> Signup and view all the answers

    How many latches would a memory with an address space of 256 K and 8 bits per address contain?

    <p>2,097,152 latches</p> Signup and view all the answers

    What occurs when requested data is found in the upper level of the memory hierarchy?

    <p>Hit (B)</p> Signup and view all the answers

    The hit rate is defined as the percentage of memory accesses that result in a miss.

    <p>False (B)</p> Signup and view all the answers

    What is the term used for the fraction of memory accesses not found in the upper level?

    <p>miss rate</p> Signup and view all the answers

    If the data requested by the processor is not located in the upper level, this is called a __________.

    <p>miss</p> Signup and view all the answers

    What is the minimum unit of information in a two-level memory hierarchy?

    <p>Block (D)</p> Signup and view all the answers

    The miss rate can also refer to misses per memory reference.

    <p>True (A)</p> Signup and view all the answers

    How is the hit ratio often used?

    <p>As a measure of memory hierarchy performance</p> Signup and view all the answers

    What does a memory capacity of 4K x 8 indicate?

    <p>A memory device with a word size of 8 bits and 4096 words (A)</p> Signup and view all the answers

    Direct access memory allows for random access without a unique address for individual blocks.

    <p>False (B)</p> Signup and view all the answers

    What characterizes volatile memory?

    <p>It loses data when power is turned off.</p> Signup and view all the answers

    The maximum number of bits that can be read or written into memory at a time is called the ______.

    <p>unit of transfer</p> Signup and view all the answers

    Match the access methods with their descriptions:

    <p>Sequential = Start at the beginning and read through in order Direct = Access by unique block addresses Random = Access by exact address identification Associative = Location by content comparison</p> Signup and view all the answers

    Which of the following is considered nonvolatile memory?

    <p>Disk (D)</p> Signup and view all the answers

    Memory cycle time only includes the time required for access, excluding recovery time.

    <p>False (B)</p> Signup and view all the answers

    Name any two types of memory classified under physical types.

    <p>Semiconductor memory, Magnetic memory</p> Signup and view all the answers

    Flashcards

    Memory Unit

    Data stored and retrieved in memory based on addresses.

    Addressable Word

    The largest item (e.g., 8, 16, 32, 64 bits) of data which can be accessed in memory using an address.

    Byte-addressable system

    A memory system where addresses correspond to individual bytes.

    Little-Endian

    Data stored in memory with the least significant byte first at the lower address.

    Signup and view all the flashcards

    Big-Endian

    Data stored in memory with the most significant byte first at the lower address.

    Signup and view all the flashcards

    Word (Memory)

    Fixed-size group of bits (e.g., 8, 16, 32, 64) used for data storage.

    Signup and view all the flashcards

    Address Input

    Number of bits needed to specify a location in memory.

    Signup and view all the flashcards

    Byte Ordering

    The sequence in which bytes of a multi-byte data element are stored in memory(Little-Endian vs Big-Endian).

    Signup and view all the flashcards

    Von Neumann Architecture

    A computer architecture where data and instructions are stored in the same memory.

    Signup and view all the flashcards

    Main Memory (Primary Memory)

    Memory that communicates directly with the CPU, used for storing currently active programs and data.

    Signup and view all the flashcards

    Auxiliary/Secondary Memory

    Memory providing backup storage for programs and data, not directly accessed by the CPU.

    Signup and view all the flashcards

    RAM (Random Access Memory)

    Read-write memory that's quickly accessed by the CPU for currently used data and programs.

    Signup and view all the flashcards

    Static RAM (SRAM)

    RAM type using latches to store data, typically faster and more expensive than DRAM.

    Signup and view all the flashcards

    Dynamic RAM (DRAM)

    RAM type that stores data as electrical charges, typically slower and less expensive than SRAM.

    Signup and view all the flashcards

    ROM (Read-Only Memory)

    Stable memory in a computer system that resists power loss and is used to store BIOS and other essential programs, but is not directly writable by the processor.

    Signup and view all the flashcards

    Memory Address

    A location in memory that stores data and is identified by a unique number for referencing.

    Signup and view all the flashcards

    Memory Latches

    Electronic switches that store data in a memory device.

    Signup and view all the flashcards

    Address Space

    The total number of addresses available in a memory system.

    Signup and view all the flashcards

    Data Retention

    Ability of memory to hold data without power.

    Signup and view all the flashcards

    BIOS

    Basic Input/Output System, a set of instructions stored in ROM that the computer uses to initialize when it starts.

    Signup and view all the flashcards

    What is ROM?

    Read-Only-Memory (ROM) is a type of memory that stores data permanently and cannot be easily changed. Information in ROM is preserved even when the power is off.

    Signup and view all the flashcards

    What is BIOS?

    The Basic Input Output System (BIOS) is a special program stored in ROM that helps a computer start up. It tells the processor how to access its resources.

    Signup and view all the flashcards

    What does nonvolatile mean?

    Nonvolatile memory refers to data being retained even without power. ROM is a nonvolatile memory type.

    Signup and view all the flashcards

    How to change information in ROM?

    Information in ROM can only be altered by physically changing the circuitry, not through regular programs.

    Signup and view all the flashcards

    What is ROM used for?

    ROM is commonly used to store essential boot programs, firmware, and data that rarely changes.

    Signup and view all the flashcards

    What is a masked ROM?

    Masked ROM is a type of ROM where data is programmed directly during the manufacturing process.

    Signup and view all the flashcards

    What is PROM?

    Programmable Read-Only Memory (PROM) can be programmed once by the user.

    Signup and view all the flashcards

    What is EPROM?

    Erasable Programmable ROM (EPROM) can be erased using ultraviolet light and then reprogrammed.

    Signup and view all the flashcards

    Memory Capacity

    The total amount of data a memory device can store, determined by the number of words and the word size (number of bits per word).

    Signup and view all the flashcards

    Word Size

    The number of bits that constitute a single unit of data that can be accessed in memory. Common sizes are 8, 16, 32, and 64 bits.

    Signup and view all the flashcards

    Unit of Transfer

    The maximum number of bits that can be read or written to memory at one time. It's typically governed by the width of the data bus and word size.

    Signup and view all the flashcards

    Sequential Access

    A method of accessing data by starting at the beginning and reading through in order. Access time depends on the data's location and previous access point.

    Signup and view all the flashcards

    Direct Access

    A method of accessing data by jumping to the vicinity of the desired location and then sequentially searching. Access time depends on location but is faster than sequential.

    Signup and view all the flashcards

    Random Access

    A method where each data location is identified by a unique address. Any location can be accessed directly and quickly.

    Signup and view all the flashcards

    Associative Access

    A method where data is located by comparing the requested data with contents of a portion of the store.

    Signup and view all the flashcards

    Access Time

    The time it takes for a memory device to retrieve data after receiving the address of the desired data location.

    Signup and view all the flashcards

    Memory Hierarchy

    A system of multiple levels of memory with different speeds and costs, where data is copied between adjacent levels.

    Signup and view all the flashcards

    Block (Memory)

    The smallest unit of information that can be moved between levels in a memory hierarchy.

    Signup and view all the flashcards

    Hit Rate

    The fraction of memory accesses that are found in the upper level of the hierarchy.

    Signup and view all the flashcards

    Miss Rate

    The fraction of memory accesses that are not found in the upper level of the hierarchy.

    Signup and view all the flashcards

    Performance of Memory Hierarchy

    Measured by how often hits occur (hit rate) and how quickly data can be retrieved.

    Signup and view all the flashcards

    Study Notes

    CS 151: Computer Organization and Architecture I - Lecture 3a - The Memory System

    • The memory system is the central part of a computer that stores programs and data. It is organized using memory locations and addresses that determine how the computer manages information.
    • Information stored includes programs, data, and results of computations. Memory allows programs and data to be stored and executed.
    • Memory is byte-addressable. This means each memory location is assigned a unique identifier, "memory address." A word is typically grouped into 8 bits (a byte). Addressing bit count (k) and bit per location (n) are used in determining address space (total accessible memory).
    • Memory unit calculations example is shown for 32-bit computer addressing 232 = 4GB of physical memory.
    • Data is written to and retrieved from memory using addresses.
    • Memory technologies include RAM (Random Access Memory) and ROM (Read-Only Memory).
    • RAM is a read-write memory (easily accessed). Data is lost when power is removed (volatile).
    • ROM is a read-only memory used for permanent storage. Data is not lost when power is removed (non-volatile).
    • Memory is organized in a hierarchy (different types and levels of memory).
    • The locality principle is fundamental in computer architecture. Several questions about memory hierarchies help students understand the memory hierarchy tradeoffs.
    • The four questions for Memory levels are: Where can a block be placed in the upper level? How a block is found if it's available in the upper level? Which block should be replaced on a miss? What happens on a write?
    • CPU registers (fast memory) are used to temporarily store data, used for operations during data transfer between CPU and memory.
    • Types of CPU registers explained.
    • Main memory (primary memory) is a random access memory used to store information while a computer is running.
    • Secondary memory (e.g., hard disk, CDs) stores large quantities of data permanently.
    • Main memory works as middle level and can transfer data to other levels, such as secondary memory.
    • Two types of RAM, SRAM and DRAM, have different characteristics (cost and speed) that make them suited for different applications within memory hierarchies.
    • Byte ordering in memory (explained with example) includes little and big endian.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    CS 151: Computer Organization and Architecture I Lecture Notes PDF

    Description

    Explore the fundamental concepts of the memory system in computer organization. This quiz covers memory locations, addressing, types of memory like RAM and ROM, and how data is managed in a computer. Test your understanding of how memory supports program execution and information storage.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser