Sy Fundamentals Flashcards
(43 cards)
What is the Program Counter (PC) in the CPU?
Holds address of the next instruction to fetch.
The Program Counter is a register that keeps track of the address of the next instruction to be executed. It updates after each instruction is fetched or can be loaded with a new address if there is a jump or branch in the program.
What does the Control Unit (CU) do?
Manages instructions and data flow.
The Control Unit decodes and executes instructions by directing the flow of data within the CPU. It ensures that the correct data is retrieved from memory and sent to the appropriate components (e.g., ALU, registers).
What is the role of the Arithmetic Logic Unit (ALU)?
Performs arithmetic and logical operations.
The ALU is responsible for carrying out all basic arithmetic operations (e.g., addition, subtraction) and logical operations (e.g., comparisons, AND/OR operations) in the CPU.
What are Registers in the CPU?
Fast storage for data and instructions.
Registers are small, ultra-fast memory locations within the CPU. They store data and instructions that the processor is currently using, allowing quick access during computations.
What is Cache in the CPU?
Fast memory close to the CPU.
Cache memory stores frequently accessed data and instructions, speeding up the CPU by reducing the time spent retrieving data from slower main memory (RAM).
What are Buses in the CPU?
Pathways for data transfer.
Buses are electrical pathways that transfer data, instructions, and control signals between different components of the computer, such as between the CPU and RAM.
What does the Clock in the CPU do?
Dictates CPU refresh rate (MHz).
The clock is an internal timing mechanism that dictates how many cycles per second the CPU executes operations, typically measured in megahertz (MHz). It sets the pace at which data is processed.
What is the purpose of the Program Counter (PC) register?
Holds the address of the next instruction.
The Program Counter register stores the address of the next instruction that needs to be fetched for execution. After each instruction is executed, the PC is updated to point to the next instruction.
What does the (MAR) do?
Memory Address Register- Holds address of data to be fetched.
The MAR holds the address in memory from where data is to be read or written. It communicates with the memory unit to access the specified location.
What is the (MDR) used for?
Memory Data Register- Holds data fetched from memory.
The MDR temporarily stores data that is read from memory or data that is about to be written to memory, allowing the CPU to process it.
What is the function of the (CIR)?
Current Instruction Register-Holds decoded instruction.
Also know as “IR”
The CIR stores the current instruction that is being decoded and executed by the CPU. It helps ensure that the CPU is working on the correct instruction at all times.
What is the role of the (ACC)?
Accumulator-Stores ALU results.
The Accumulator is used by the ALU to store intermediate results of arithmetic and logical operations. It acts as temporary storage for values being processed.
What is the role of the Kernel in the OS?
Manages hardware and system resources.
The kernel is the central part of the operating system, responsible for interacting directly with hardware, managing system resources (CPU, memory, I/O devices), and ensuring that all processes are executed effectively.
What does Memory Management in the OS do?
Allocates memory to programs.
The memory management component of the OS handles the allocation and deallocation of memory for processes, ensuring that each program gets the necessary memory and avoids conflicts.
What does the Input/Output layer of the OS manage?
Manages communication with peripherals.
The I/O layer enables communication between the OS and external hardware devices such as keyboards, printers, and storage devices, ensuring data is transferred correctly.
What does the File Management System do in the OS?
Handles file storage and permissions.
The file management system is responsible for organizing, storing, and accessing files on storage devices, and ensuring proper access control and file permissions for users and applications.
What is the User Interface layer of the OS?
Provides interaction between user and OS.
The User Interface (UI) layer allows users to interact with the OS through graphical (GUI) or command-line interfaces (CLI), enabling users to perform tasks like file manipulation and program execution.
What is the ‘Ready’ state in the Kernel?
Process waits for CPU time.
In the ‘Ready’ state, a process is waiting to be assigned CPU time. The process is ready to execute but is waiting for the OS to schedule it.
What is the ‘Running’ state in the Kernel?
Process is executed by CPU.
The process is currently being executed by the CPU. It has been assigned a time slice or CPU time by the scheduler.
What is the ‘Waiting’ state in the Kernel?
Process paused, waiting for I/O.
Blocked.
A process is in the ‘Waiting’ state when it cannot proceed because it is waiting for an event, such as input/output completion or resource availability.
What is Round Robin scheduling?
Each process gets equal time slices.
Round Robin scheduling is a fair CPU scheduling method where each process gets a fixed time slice, and the CPU cycles through the processes in a round-robin manner.
What is First Come First Served scheduling?
Processes handled in order of arrival.
In First Come First Served (FCFS) scheduling, processes are executed in the order they arrive in the ready queue, without any prioritization.
What is a TSR ?
(Terminate and Stay Resident)-Software that remains in memory to respond to events.
TSR programs do not fully exit after execution; they stay in memory to handle events like system interruptions or can be activated again without reloading.
What is the role of a device driver?
Allows OS to communicate with hardware devices.
A device driver acts as a translator between the OS and hardware devices, enabling the OS to send and receive data from devices like printers, scanners, and network adapters.
