CPU Architecture, Memory and Storage Flashcards

CPU architecture, memory, and storage.

What does the CPU do?

The CPU (Central Processing Unit) is the brain of the computer. It retrieves instructions from memory, decodes them, and executes them. This is how computers perform tasks.

What is a microprocessor?

A microprocessor is a small chip that functions as the CPU in computers. It performs arithmetic, controls the computer, and uses registers for memory.

What do users input into a computer?

Users input data like text, numbers, images, and sounds, as well as commands that tell the computer what to do with the data. The CPU then processes this information.

What is the Von Neumann Architecture?

The Von Neumann Architecture is a design for the CPU that includes an arithmetic logic unit, a control unit, memory, and input/output devices. It's the basis for most computers today.

What are the main parts of the Von Neumann architecture?

The main parts include:

1. Control Unit (CU):

   • Manages the operations of the CPU by fetching, decoding, and executing instructions.

2. Arithmetic Logic Unit (ALU):

   • Performs arithmetic and logic operations.

3. Registers:

   • Provide fast access to data that the CPU is currently using.

4. Buses:

   • Wires that allow different parts of the CPU to communicate with each other.

What does the Control Unit (CU) do?

The Control Unit fetches instructions from memory, decodes them, and controls the flow of data within the CPU. It tells the computer what to do.

What is the Arithmetic Logic Unit (ALU)?

The Arithmetic Logic Unit performs all the arithmetic (add, subtract, multiply, divide) and logic (AND, OR, NOT) operations necessary to carry out instructions.

What are Registers?

Registers are small, fast storage locations within the CPU that hold data and instructions that are currently being processed. They speed up program execution.

What are the five main registers in a CPU?

The five main registers are:

1. Program Counter (PC):

   • Holds the address of the next instruction to be executed.

2. Memory Address Register (MAR):

   • Stores the address in memory that is being read from or written to.

3. Memory Data Register (MDR):

   • Holds the data that is being transferred to or from memory.

4. Accumulator (ACC):

   • Stores the results of calculations performed by the ALU.

5. Current Instruction Register (CIR):

   • Holds the current instruction that is being executed.

What is the purpose of the Program Counter (PC)?

The Program Counter holds the memory address of the next instruction to be executed, ensuring the CPU knows where to find the next instruction.

What is the purpose of the Memory Address Register (MAR)?

The Memory Address Register stores the memory address that the CPU will use to read data from or write data to, facilitating access to specific memory locations.

What is the purpose of the Memory Data Register (MDR)?

The Memory Data Register temporarily holds the data that has been read from memory or is about to be written to memory, acting as a buffer during data transfer.

What is the purpose of the Current Instruction Register (CIR)?

The Current Instruction Register holds the instruction that has just been fetched from memory and is about to be executed by the CPU, ensuring the correct operation is performed.

What is the function of the Accumulator (ACC)?

The Accumulator stores the results of arithmetic and logical operations performed by the ALU. It is a temporary storage location for computed values.

What is a Bus in the context of CPU architecture?

A bus is a collection of wires that transmits data, addresses, and control signals between computer components, enabling communication between different parts of the CPU and other devices.

What are the three types of buses in a CPU?

The three types of buses are:

1. Address Bus:

   • Carries memory addresses from the CPU to RAM, specifying where data should be read from or written to.

2. Data Bus:

   • Transports data between the CPU and other components, enabling both reading and writing of data.

3. Control Bus:

   • Sends control signals from the CPU to coordinate and synchronize operations.

What does the Address Bus do?

The Address Bus carries memory addresses from the CPU to RAM, specifying the exact location in memory for reading or writing data. It is unidirectional, meaning data flows only from the CPU.

What does the Data Bus do?

The Data Bus moves data between the CPU and other parts. It is bidirectional, so data can be read from and written to memory.

What is the role of the Control Bus?

The Control Bus carries control signals from the CPU to coordinate operations. These signals include commands like "read", "write", and "interrupt".

What is the Fetch-Decode-Execute (FDE) cycle?

The Fetch-Decode-Execute (FDE) cycle is the fundamental process by which the CPU retrieves an instruction from memory, decodes it to understand what operation needs to be performed, and then executes that instruction. This cycle repeats continuously.

What happens during the Fetch stage of the FDE cycle in relation to the MAR?

During the Fetch stage, the address of the next instruction is copied from the Program Counter (PC) into the Memory Address Register (MAR). This tells the memory system which instruction the CPU requires.

What are the two parts the instruction is split into during the decode stage?

During the decode stage, the instruction is broken down into two main parts:

1. Opcode (Operation Code):

   • Specifies the operation to be performed, e.g., addition, subtraction, data movement.

2. Operand:

   • Specifies the data or memory location that will be used in the operation.

What are the three characteristics that impact CPU performance?

The three key factors that affect CPU performance are:

1. Clock Speed:

   • The rate at which the CPU can execute instructions, measured in Hertz (Hz).

2. Cache Size:

   • The amount of high-speed memory that the CPU has available for quick access to frequently used data.

3. Number of Cores:

   • The number of independent processing units within the CPU, allowing it to perform multiple tasks simultaneously.

What is the purpose of Cache memory?

Cache memory is a small, fast memory that stores frequently used instructions and data, allowing the CPU to access them more quickly than if they were stored in main memory, thus improving performance.

What is an Instruction Set?

The instruction set is the complete set of commands that a CPU can understand and execute. It defines the functionality of the CPU.

What is an Embedded System?

An embedded system is a specialized computer system designed to perform a dedicated function within a larger device, such as a washing machine or a car’s engine control unit.

What are Input Devices?

Input devices allow users to input data and commands into a computer system. Examples include keyboards, mice, touchscreens, and microphones.

What are Output Devices?

Output devices display or present information from a computer to the user. Common examples are monitors, printers, speakers, and projectors.

What are Sensors?

Sensors are input devices that measure physical quantities like light, temperature, pressure, or motion and convert them into electrical signals that a computer can interpret.

Examples of primary storage.

Examples of primary storage include RAM (Random Access Memory), ROM (Read-Only Memory), cache memory, and registers. These provide fast access for the CPU.

What is Secondary Storage?

Secondary storage is used to store data persistently, even when the computer is turned off. Examples include hard drives, SSDs (Solid State Drives), and USB flash drives.

What are the three types of secondary storage?

The three main types of secondary storage are:

1. Optical Storage:

   • Uses lasers to read and write data on media like CDs, DVDs, and Blu-ray discs.

2. Magnetic Storage:

   • Stores data by magnetizing parts of a material, like in hard drives.

3. Solid State Storage:

   • Uses flash memory, which is faster and more durable than hard drives.

What is Virtual Memory?

Virtual memory is a memory management technique that uses a portion of the hard drive as an extension of RAM, allowing the computer to run more applications or handle larger datasets than the physical RAM would otherwise allow.

What is Cloud Storage?

Cloud storage involves saving data on remote servers accessed via the Internet, providing benefits such as scalability, accessibility, and data backup. Example services include Google Drive and Dropbox.

What are the different types of data inputted into a computer?

Different types of data inputted into a computer include text, numbers, images, and audio. Each requires different processing and storage methods.

What are commands in the context of user input?

Commands are instructions given by a user to the computer to perform specific actions, such as opening a file, running a program, or saving a document.

How does the computer process user inputted data and commands?

The CPU fetches instructions, decodes them, and then executes them. Data is often stored in memory for later use or further processing.

What input devices are commonly used to input data and commands?

Common input devices used to enter data and commands include keyboards, mice, touchscreens, and microphones.

Why is user input essential for computers?

User input is essential because it allows users to control computer systems and direct them to perform specific tasks, making computers useful and interactive.

What is an IP Address?

An IP address (Internet Protocol address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication.

What is a MAC Address?

A MAC address (Media Access Control address) is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment.

What is the purpose of a Router?

A router is a device that sends data between networks, directing traffic on the internet.