Types of Interrupts

1. Software Interrupt

A sort of interrupt that is produced by the software is a software interrupt, sometimes referred to as a trap or a system call. It is used to ask the operating system or other system software to perform a certain service or activity. A program normally creates a software interrupt by utilizing a particular instruction, such as INT in x86 assembly language or a system call in a high-level programming language. When the processor comes across this instruction, it will store the program’s current state and transfer control to a specific location in memory where the system software or operating system can handle the request. Allocating memory, reading from or writing to a file, starting or stopping a process, and sending or receiving data from a network are a few services that can be requested using a software interrupt. In order to deliver services to user-space applications, system software like device drivers, libraries, and operating systems also employs software interrupts.

2. Hardware Interrupt

An external device, such as a keyboard or mouse, will signal the CPU with a hardware interrupt when it needs the processor’s attention. An interrupt controller is a piece of specialized hardware that produces these interruptions by receiving signals from the devices and sending them to the processor. When a hardware interrupt occurs, the processor saves the program’s current state and moves control to an area of memory known as an interrupt vector so that the proper interrupt handler can be run there. A short piece of code called an interrupt handler is created to support the particular device that caused the interrupt.Input/output processes such as receiving data from a keyboard, transferring data to a printer, or interacting with a network are all handled via hardware interrupts. They increase the system’s overall efficiency by enabling the processor to carry out other tasks while it waits for input or output operations to finish.

3. Maskable Interrupts

Interrupts that can be temporarily disabled or “masked” by the processor are known as maskable interrupts.

4. Non-maskable Interrupts

These must be handled right away because the processor cannot ignore them or mask them.

5. Inter-processor Interrupts

In a multiprocessor system, interprocessor interruptions are used to facilitate communication between different processors.

6. Inter-System Interrupts

Inter-system interrupts: These are used to alert other systems to an incident that needs their attention.

7. Exception

Similar to interrupts, exceptions are created by the processor when particular criteria are met, such as division by zero, an invalid command, etc.

What is Interrupt Latency?

Interrupt latency is a measure of the time it takes for a computer system to respond to an external event, such as a hardware interrupt or software exception. This metric is important in determining the performance and responsiveness of a system and is a key consideration in the design and optimization of real-time and embedded systems. In this article, we will discuss the concept of interrupt latency, its importance, and some of the factors that can affect interrupt latency.

The article focuses on discussing Interrupt latency in detail. The following topics will be discussed here:

  1. What is Interrupt?
  2. What is Interrupt Latency?
  3. Cause of Interrupt Latency
  4. Arm Cortex-M Interrupt Latency
  5. Measuring Interrupt Latency
  6. Conclusion

Let’s start discussing each of these topics in detail.

Similar Reads

What is Interrupt?

An interrupt is a signal sent to the computer’s processor asking it to stop what it’s doing and start handling the interrupt right away. Devices like the keyboard, mouse and network card communicate with the processor and request services using interrupts. They are crucial to how modern operating systems function and enable the processor to react quickly to outside events. The interrupt can be emitted by hardware or software indicating an event that needs immediate attention....

Types of Interrupts

1. Software Interrupt...

What is Interrupt latency?

Interrupt latency is the time that elapses between the occurrence of an interrupt and the execution of the first instruction of the interrupt service routine (ISR) that handles the interrupt....

Importance of Interrupt Latency

Interrupt latency is an important consideration in the design and optimization of real-time and embedded systems. These systems often have hard real-time constraints, meaning that they must respond to external events within a specified time period....

Factors Affecting Interrupt Latency

There are several factors that can affect interrupt latency, including:...

Interrupt Prioritization

When a processor receives a higher-priority interrupt while it is still addressing a lower-priority interrupt, this is known as interrupt preemption. In this scenario, the processor will instantly halt the handler for the current interrupt and start the handler for the interrupt with a higher priority....

Arm Cortex-M Interrupts Latency

The ARM Cortex-M microcontroller series has a low interrupt latency and is frequently used in embedded systems. The nested vectored interrupt controller (NVIC) on Cortex-M processors enables effective interrupt handling. Between the time the interrupt occurs and the time the processor starts executing the interrupt service routine, there are only a few instructions in the NVIC (ISR)....

Measuring Interrupt Latency

Interrupt latency can be measured using various techniques, such as the use of specialized hardware, software tools, and benchmarks. It’s also possible to use different system performance monitoring tools to measure interrupt latency. It’s important to note that the way of measuring can affect the results as well, some tools or methods might measure only the time from the interrupt request to the ISR start while others may include other events as well such as disabling interrupt or switch process, etc. There are three types of latency that are measured:...

Conclusion

Interrupt latency is a measure of the time it takes for a computer system to respond to an external event. It is an important metric in determining the performance and responsiveness of a system, particularly in real-time and embedded systems. Factors such as hardware, operating system, interrupt priority, and system load can all affect interrupt latency. Measuring interrupt latency can be done using various techniques and tools. It is important for system designers and developers to understand and optimize interrupt latency in order to ensure the reliability and performance of their systems....

Contact Us