Computer Architecture: Components, Functions, and How They Work
Computer Components
Computing is the automatic processing of information. The information must be in digital format. Numbers are represented in base 2. Images must be encoded as ordered pixels. Sound waves should also be coded for processing. A computer is an electronic device capable of receiving and processing digital data, and returning the result.
The early evolution of computing machines worked with fixed programs. A calculator had a fixed program. You could do basic math, but not use it as a word processor or to run games. To change a program on a machine like this, you had to reconnect, restructure, or even redesign it. That is, the first computers were not “programmed” but “engineered.”
Computer Architecture
Computer Architecture is the conceptual design and fundamental operational structure of a computer system, with special emphasis on how the central processing unit (CPU) works internally and accesses addresses in memory. When you create a new PC, you look especially at features, performance, and cost.
The Layers of Abstraction:
- Hardware
- Firmware
- Assembler
- OS Kernel
- Application
Hardware:
All tangible and physical parts of a computer. Components can be electric, electronic, electromechanical, and mechanical; including boxes, etc.
Firmware:
This is the permanent software embedded in the hardware. It’s a block of program instructions for specific purposes, stored in ROM. It contains instructions and tells the computer how to work with different devices.
Assembler Language (Firmware):
Assembly language is a low-level programming language. It is a symbolic representation of the binary code necessary to program a specific processor architecture. It uses mnemonics (short codes) that are easier to remember than binary. An assembler is a computer program that translates assembly language into machine language.
The Kernel:
The kernel is the fundamental part of an operating system. This software is responsible for providing various programs secure access to computer hardware. It governs which applications have priority, choosing the processes that are running on your computer.
Multiplexing: The kernel manages how different programs share access to hardware resources, like the CPU and memory.
The operating system software is responsible for managing resources in a terminal. It is the host of applications that the computer is processing.
Hardware
There are two groups of hardware: central and peripheral. The central components are all that is inside the computer case, and the peripherals are the parts that are outside the case. Peripherals include input devices, which are used to enter information into the computer, and output devices, which display information from the computer.
Input – Output, Process, Transport, and Storage
Central Elements of the Hardware:
Motherboard:
Also known as the mainboard, it is a printed circuit board on which you connect other devices. It houses the CPU, RAM, BIOS, and expansion slots for connecting peripherals.
CPU:
This is the central processing unit, the main microprocessor that is mounted on the motherboard. Other printed circuit boards are called cards (network cards, graphics cards, etc.)
Introduction to Von Neumann Architecture
John von Neumann proposed the concept of the stored program, which was the basis for the construction of modern electronic computers. The concept of a program stored in memory completely changed the design of computers. It allows us to permanently connect the different units of the computer, coordinated by a central unit. On the other hand, it allows for the possibility that programs modify themselves during execution. The difference between having a printed circuit board and having the order among the circuits is that we can rearrange them and be changed.
Von Neumann Bottleneck:
The separation between the CPU and memory causes a problem known as the Von Neumann bottleneck. This means that processor performance is limited by the speed of transferring data between the CPU and RAM.
CPUs
CPU:
The CPU is the brain of the computer, in charge of controlling and processing data and executing program instructions. It is made up of functional units:
- ALU – Arithmetic-Logical Unit
- CU – Control Unit
- Memory Device / Bus data
Records:
Registers are small, high-speed storage locations within the CPU that hold data and instructions being processed.
Performing Calculations:
- Arithmetic: addition, subtraction (and perhaps multiplication and division)
- Boolean logic: AND, OR, XOR, NOT
- Bit shifting
- Comparisons
Components:
- Accumulator: A register that stores the results of arithmetic and logical operations.
- Operational circuit: Performs arithmetic and logical operations.
- Registers: Store data and instructions.
- Flags: Bits that indicate the status of the CPU and the results of operations (e.g., zero flag, carry flag).
Major Components:
- Instruction decoder (DI): Extracts and analyzes the opcode of the instruction. Retrieves information from RAM.
- Clock: Generates a series of electrical impulses separated by determined intervals. It sets the execution times of each instruction and the pace of operation of the DI.
- Sequencer: Generates orders synchronized with the clock, ensuring that instructions are executed in the correct order.
Organization of a Program:
- Fetch the next instruction from memory at the address indicated by the program counter.
- Increase the program counter to point to the next instruction.
- Decode the instruction by the control unit.
- Fetch the operands (data) required by the instruction.
- Execute the instruction.
- Go back to step 1.
Central Processing Unit (CPU)
Registers:
Small, high-speed storage locations within the CPU that hold data and instructions being processed.
L1 Cache:
Internal memory (temporary) that stores frequently used data and instructions. This memory is much faster than main memory but also much more expensive.
Main Memory or RAM (Random Access Memory):
- Stores: Running program instructions, data that the program works with.
- Fields: 8 bits (1 byte)
- Volatile memory: The memory contents are lost when you turn off the power.
- Memory locations: Each location in memory is identified with a unique address.
- Memory address: The control unit accesses different memory locations according to their address.
Input/Output Unit:
Enables the exchange of information between the computer and the outside world, allowing users to connect the processor with other devices.
Bus:
The pathway through which information flows between different units of the computer. Types of buses:
- Data Bus
- Address Bus
- Control Bus
Bus size is indicated by the number of bits it can transfer simultaneously: 16-bit, 32-bit, or 64-bit.
Data Bus:
Allows the exchange of data between the CPU and other units. Composed of several lines. Current CPUs use up to 64 bits.
Address Bus:
Transmits addresses between the CPU and memory, working in conjunction with the data bus. It’s needed to find the addresses of the data. The width of the address bus limits the amount of RAM that can be addressed.
Control Bus:
Used by the CPU to control the other components of the computer.
Motherboard
The motherboard is the largest circuit board in a PC.
Function:
Used to connect all the elements of a computer, including the microprocessor, RAM, BIOS, and expansion cards. It also connects to the power supply.
The Form Factor:
The form factor is the physical size and layout of a motherboard. A motherboard can be square or rectangular. Its physical dimensions are the width and height. The position of the anchors are the coordinates where the screws are located. The areas where components are placed, i.e., the expansion slots, the physical connector… the power supply connector, electrical connections, i.e., cables that connect the motherboard to the power supply.
Standards:
- AT
- Baby AT
- ATX
- BTX
- NLX
- LPX
AT:
The first standard, released in 1984. Their sizes were 12” wide x 11-13” deep. The only integrated component was the keyboard. All I/O ports were wired.
ATX:
Created in 1995 and is the most used today. Its dimensions are 305 mm x 244 mm. It has a better placement of components and allows for better ventilation. The connectors for IDE devices and floppy drives are closer to reduce the length of the cables.
Elements of the Motherboard
Socket:
The connector for the microprocessor (CPU).
Memory Slots:
Where you install the RAM modules. Different types depending on the type of RAM: SIMMs or DIMMs.
Chipset:
A set of chips that control the flow of data between the CPU, memory, and peripherals. The chipset determines the type of processor, RAM, and expansion slots that the motherboard supports.
Chipset Features:
Control data, instructions and control signals between the CPU and memory bus. Manages the transfer of data between the CPU, memory and peripherals. Support expansion socket. quality and characteristics depend Chipset: Get the maximum performance or not the microprocessor. The possibilities of upgrading the computer. The use of certain advanced technologies of memories and peripherals. North Bridge Controls: How many microprocessors support plate number of processors. What type and what speed can beWhat type of RAM, what and how technology can have. The front side bus speed and multiplier factor. The South Bridge controls: The ports and buses features power management systems storage slots of expansion are long and narrow connectors are placed on the expansion cards such as graphics card, network card, etc.. Bus Width: number of lines or bits of data bus. Frequency Bus clock: it can be different from the processor. Transmission: The maximum speed of data transfer. Power connector are connected to the motherboard gives energy to all computer accessories. Connector input / output connectors for external peripherals Son, keyboard, mouse, printer, etc.. Internal Connectors (bus) connectors can be found: floppy drive, hard disk, CD-ROM, USB, serial ports BIOS The BIOS … the basic input / output. Its function is to say how we will communicate how it will communicate with internal devices. Load the operating system controls the main memory or RAM as I start the computer (which looks for the OS, read on) also tells the RAM is the computer. The battery The battery keeps the system configuration used during the sequence of the Power PC: Without it, every time engeguéssim, we introduced the characteristics of hard The date and time integral of important parameters. Over the years gradually lose this ability (like all rechargeable batteries) and comes a moment when we must change it.