Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Understanding Computer Architecture: CPU, ALU, Registers, and Memory, Slides of Computer Science

Explore the fundamental concepts of computer architecture, including the CPU, ALU, registers, and memory. Learn about their functions, subsystems, and interconnections. Understand the role of each component in processing data and instructions.

Typology: Slides

2020/2021

Uploaded on 01/27/2021

Suraba
Suraba 🇮🇳

4 documents

1 / 14

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
COMPUTER ARCHITECTURE
1
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe

Partial preview of the text

Download Understanding Computer Architecture: CPU, ALU, Registers, and Memory and more Slides Computer Science in PDF only on Docsity!

COMPUTER ARCHITECTURE

1

  • Computer Architecture:
    • The science of selecting and interconnecting hardware components that create computers
    • It will meet functional, performance and cost goals
    • It can also be described as the logical structure of the computer system
    • It forms the backbone for building successful computer system
  • CPU:
    • The brain of a computer system
    • It is a VLSI chip inside the system, plugged onto the motherboard
    • It controls all internal and external devices
    • It operates only on binary data i.e 0 and 1
  • Functions of CPU:
    • Carrying out arithmetic and logic functions
    • Controlling the use of main storage to store data and instructions
    • Controlling the sequence of operations
    • Controlling all the parts of the computer system 2
  • Logical Unit (LU):
    • The logical unit enables the CPU to make logical operations based on the instructions provided
    • These operations are the logical comparison between the data items
    • This unit can compare numbers, letters or special characters
    • They can take action based on the result of the comparison
    • The logical operations of a logic unit test three conditions:
      • Equal to
      • Less than condition
      • Greater than condition
  • Registers:
    • These are special-purpose, high-speed temporary memory units
    • These are temporary storage areas for holding various types of information such as data, instructions, addresses and the intermediate results of calculations
    • It works under the direction of the control unit to accept, hold and transfer instructions or data and perform arithmetic or logical comparisons at high speed. 4
  • Registers:
  • Various types of registers present inside a CPU:
  • Program Counter (PC)
    • It keeps track of the next instruction to be executed
  • Instruction Register (IR)
    • It holds the instruction to be decoded by the control unit
  • Memory Address Register (MAR)
    • It holds the address of the next location in memory to be accessed
  • Memory Buffer Register (MBR)
    • It is used for storing data either coming to the CPU or data being transferred by the CPU
  • Accumulator (ACC)
    • It is a general purpose register used for storing temporary results and results produced by ALU
  • Control Unit:
    • It is the heart of the CPU
    • It controls the I/O devices and transfer of data to and from the primary storage
    • It itself is controlled by the individual instructions in programs located in the primary storage 5
  • Main memory unit
    • CPU accesses the main memory in a random manner
    • The CPU can access any location of this memory to either read information from it or store information in it
    • The primary memory is of two types:
    • Random access memory (RAM)
    • Read only memory(ROM)
  • Random access memory (RAM):
    • It directly provides the required information to the processor
    • It is a block of sequential memory locations, each of which has a unique address determining the location and those locations contain a data element
    • It stores programs and data that are in active use
    • RAM can be further classified into two categories: DRAM and SRAM
  • Dynamic Random Access Memory (DRAM):
    • It holds the data in dynamic manner with help of a refresh circuitry
    • Each second or even less than that the content of each memory cell is read
    • This read action refreshes the contents of the memory
    • Due to refreshing action, the memory is called dynamic RAM
    • DRAMs are made from transistors and capacitors
    • The capacitor holds the electrical charge if the bit contains 1 and no charge if 7 the
  • Static Random Access Memory (SRAM):
    • SRAM along with DRAM is essential for a system to run optimally, because it is very fast as compared to DRAM
    • It is effective because most of the programs access the same data repeatedly and keeping all these information in the first SRAM
    • Data are first written to SRAM assuming that they will be used soon
    • SRAM is generally included in a computer system by the name of cache
  • Read-only Memory:
    • It can only be read, not written
    • It stores the initial start-up instructions and routines in the BIOS which can be read by the CPU, each time it is switched on
    • The instructions in the ROM are built into the electronic circuits of the chip, which is called firmware
    • The ROM is also random access in nature, which means the CPU can randomly access any location within the ROM
  • Various types of ROM:
    • Programmable read-only memory (PROM)
    • Erasable programmable read-only memory (EPROM)
    • Electrically erasable programmable read-only memory (EEPROM) 8
  • Memory Hierarchy
  • There are three fundamental types of memory in a computer

system:

  • Internal Processor Memory:
    • This memory is placed within the CPU or is attached to a special fast bus
    • Internal memory usually includes cache memory and special registers, both of which can be directly accessed by the processor
    • This memory is used for temporary storage of data and instructions on which the CPU is currently working
    • Processor memory is the fastest among all the memories but is most expensive also
  • Primary Memory:
    • Random access memory (RAM) and Read-only memory (ROM) fall under the category of the primary memory which is also known as main memory
    • Every computer comes with a small amount ROM, which contains the boot firmware (called BIOS)
    • It is volatile in nature i.e. when the power is switched off, the data in this memory is lost 10
  • Memory Hierarchy
  • Secondary Memory:
    • This is also known as auxiliary memory
    • The secondary memory provides backup storage for instructions and data
    • The most commonly used secondary storage devices are magnetic disks and magnetic tapes
    • These are the least expensive as well as have larger storage capacity than primary memory
    • The instructions and data stored on secondary storage devices are permanent in nature
  • The secondary memory can also be used as overflow memory when

the capacity of main memory is surpassed

  • Registers, Cache memory Internal Processor Memory
  • RAM, ROM Primary Memory
  • Hard Disk, magnetic Disk Secondary memory 11

COST

Access Speed

Storage Capacity

  • These lines are broadly categorized into three functional groups:
    • Data lines
    • Address lines
    • Control lines
  • Data Lines:
    • A path for moving data between the system modules
    • These are collectively known as data bus
    • Normally, a data bus consists of 8 , 16 or 32 separate lines
    • The number of lines present in a data bus is called the width of data bus
    • The width of data helps in determining the overall performance of a computer system
  • Address Lines:
    • This lines are used to designate the source of data for data bus
    • For reading or writing any information on to the memory, the CPU needs to specify the address of a particular location
    • This address is supplied by the address bus
    • Thus the width of the address bus specifies the maximum possible memory supported by a system 13
  • Control lines:
    • They are used to control the access to data and address bus
    • The control lines are collectively called control bus
    • These lines are used for the transmission of commands and timing signals (which validate data and address) between the system modules
    • Timing signals indicate whether data and address information is valid 14