8 Lecture

1. What is an interrupt? A. A type of exception B. A type of error C. A type of function call D. A type of loop Answer: A Which of the following is not an example of an interrupt? A. Keyboard input B. Mouse input C. Printer output D. Timer overflow Answer: C What is a hardware interrupt? A. An interrupt triggered by the CPU B. An interrupt triggered by an external device C. An interrupt triggered by a software program D. An interrupt triggered by a user input Answer: B What is a software interrupt? A. An interrupt triggered by the CPU B. An interrupt triggered by an external device C. An interrupt triggered by a software program D. An interrupt triggered by a user input Answer: C Which of the following is not a type of interrupt? A. Maskable interrupt B. Non-maskable interrupt C. High-priority interrupt D. Low-priority interrupt Answer: C Which of the following is true about non-maskable interrupts? A. They can be disabled by software. B. They cannot be disabled by software. C. They are triggered by external devices. D. They are triggered by software programs. Answer: B Which of the following is true about maskable interrupts? A. They cannot be disabled by software. B. They are triggered by external devices. C. They are triggered by software programs. D. They cannot be prioritized. Answer: C What is a vectored interrupt? A. An interrupt with a fixed priority level. B. An interrupt with a variable priority level. C. An interrupt that shares the same priority level as other interrupts. D. An interrupt that has a specific address assigned to it. Answer: D Which of the following is an example of a non-maskable interrupt? A. System call B. Timer interrupt C. Power failure D. Interrupt from a mouse click Answer: C Which of the following is true about interrupt handling? A. It must be done in real-time. B. It is not a time-critical operation. C. It is done by the operating system. D. It is not necessary in modern computer systems. Answer: A
   

1. What is an interrupt handler? Answer: An interrupt handler is a function or routine that is executed in response to an interrupt. It is responsible for handling the event that caused the interrupt and returning control to the interrupted program. What is the purpose of an interrupt request (IRQ) line? Answer: The IRQ line is used to signal the CPU that an interrupt has occurred and needs to be processed. The CPU then interrupts the current program and jumps to the corresponding interrupt handler. What is a hardware interrupt? Answer: A hardware interrupt is an interrupt that is triggered by an external device, such as a keyboard, mouse, or timer. It is handled by the operating system or device driver. What is a software interrupt? Answer: A software interrupt is an interrupt that is triggered by a software instruction, such as a system call or software interrupt instruction. It is used to request a service from the operating system or to perform a software task. What is the difference between a maskable and non-maskable interrupt? Answer: A maskable interrupt can be disabled by software, while a non-maskable interrupt cannot. Non-maskable interrupts are typically used for critical events that cannot be ignored, such as power failures or hardware errors. What is interrupt latency? Answer: Interrupt latency is the time it takes for the system to respond to an interrupt request and begin executing the corresponding interrupt handler. It can affect the responsiveness of the system and must be minimized for time-critical operations. What is a vectored interrupt? Answer: A vectored interrupt is an interrupt that has a specific address assigned to it. When the interrupt occurs, the CPU jumps directly to the corresponding interrupt handler, rather than searching for it in a table. What is interrupt masking? Answer: Interrupt masking is the process of disabling or enabling interrupts. This can be done by setting a flag in the CPU's interrupt mask register, which controls whether interrupts can be processed or not. What is a priority interrupt? Answer: A priority interrupt is an interrupt that is assigned a priority level, based on its importance or urgency. When multiple interrupts occur simultaneously, the CPU will handle the highest-priority interrupt first. What is interrupt chaining? Answer: Interrupt chaining is a technique used to handle multiple interrupts of the same type, such as multiple timer interrupts. When an interrupt occurs, the corresponding interrupt handler may chain to another handler to process additional interrupts of the same type.
   

Interrupts are a mechanism used by computer systems to handle events that require immediate attention. Interrupts can be triggered by external devices, such as keyboards or mice, or by software instructions, such as system calls. When an interrupt occurs, the current process is interrupted, and the control is transferred to a specific piece of code called an interrupt handler. The interrupt handler is responsible for performing the necessary actions in response to the interrupt. Interrupts can be classified as either hardware interrupts or software interrupts. Hardware interrupts are triggered by external devices, while software interrupts are triggered by software instructions. Hardware interrupts are typically used for events that require immediate attention, such as input from a keyboard or mouse. Software interrupts, on the other hand, are used for system calls or other software operations. Interrupts can also be classified as either maskable interrupts or non-maskable interrupts. Maskable interrupts can be disabled by software, while non-maskable interrupts cannot be disabled. Non-maskable interrupts are typically used for critical events that cannot be ignored, such as power failures or hardware errors. Interrupt latency is the time it takes for the system to respond to an interrupt request and begin executing the corresponding interrupt handler. Interrupt latency can have a significant impact on system performance and must be minimized for time-critical operations. This can be achieved through the use of interrupt controllers or by using hardware that supports fast interrupt response times. Priority interrupts are used to handle multiple interrupts that occur simultaneously. Each interrupt is assigned a priority level, based on its importance or urgency. When multiple interrupts occur simultaneously, the CPU will handle the highest-priority interrupt first. Interrupt chaining is a technique used to handle multiple interrupts of the same type. When an interrupt occurs, the corresponding interrupt handler may chain to another handler to process additional interrupts of the same type. This can be used to efficiently handle interrupts from devices that generate multiple interrupts, such as timers or network cards. Overall, interrupts are an essential part of computer systems, allowing for efficient and timely handling of events that require immediate attention. Understanding how interrupts work and how to optimize their performance is critical for developing efficient and reliable computer systems.