Search results
Results from the WOW.Com Content Network
In computer systems programming, an interrupt handler, also known as an interrupt service routine or ISR, is a special block of code associated with a specific interrupt condition. Interrupt handlers are initiated by hardware interrupts, software interrupt instructions, or software exceptions , and are used for implementing device drivers or ...
A hardware interrupt is a condition related to the state of the hardware that may be signaled by an external hardware device, e.g., an interrupt request (IRQ) line on a PC, or detected by devices embedded in processor logic (e.g., the CPU timer in IBM System/370), to communicate that the device needs attention from the operating system (OS) [7] or, if there is no OS, from the bare metal ...
In a computer, an interrupt request (or IRQ) is a hardware signal sent to the processor that temporarily stops a running program and allows a special program, an interrupt handler, to run instead. Hardware interrupts are used to handle events such as receiving data from a modem or network card , key presses, or mouse movements.
It helps prioritize IRQs so that the CPU switches execution to the most appropriate interrupt handler (ISR) after the PIC assesses the IRQs' relative priorities. Common modes of interrupt priority include hard priorities, rotating priorities, and cascading priorities. [citation needed] PICs often allow mapping input to outputs in a configurable ...
The interrupt could arrive before the DMA write was complete, and the processor could read stale data from memory. [5] To prevent this race, interrupt handlers were required to read from the device to ensure that the DMA write had finished. This read had a moderate performance penalty. An MSI write cannot pass a DMA write, so the race is ...
An interrupt vector table (IVT) is a data structure that associates a list of interrupt handlers with a list of interrupt requests in a table of interrupt vectors. Each entry of the interrupt vector table, called an interrupt vector, is the address of an interrupt handler (also known as ISR). While the concept is common across processor ...
When a signal is sent, the operating system interrupts the target process' normal flow of execution to deliver the signal. Execution can be interrupted during any non-atomic instruction. If the process has previously registered a signal handler, that routine is executed. Otherwise, the default signal handler is executed.
A reentrant interrupt handler is an interrupt handler that re-enables interrupts early in the interrupt handler. This may reduce interrupt latency. [6] In general, while programming interrupt service routines, it is recommended to re-enable interrupts as soon as possible in the interrupt handler. This practice helps to avoid losing interrupts. [7]