An Interrupt Service Routine (ISR) is a specialized function in computing that handles hardware or software interrupts by pausing the current execution flow and executing a specific routine to address the interrupt. ISRs are crucial for real-time systems as they ensure that time-sensitive tasks are managed promptly and efficiently, often with minimal latency.

Interrupt Service Routine (ISR)

An Interrupt Service Routine (ISR) is a special block of code associated with a specific interrupt condition, allowing a system to respond immediately to external or internal events, often in real-time. It temporarily halts the main program execution, executes the necessary response, and then resumes the main program, ensuring efficient and prompt handling of critical tasks.

Interrupt Service Routine

specialized function in computing

Hardware interrupts are signals sent to the processor by hardware devices to indicate an event that needs immediate attention, allowing the CPU to prioritize tasks and improve efficiency. They enable real-time processing by temporarily halting the current code execution and executing a predefined interrupt service routine (ISR) to address the event.

Hardware Interrupts

Software interrupts are signals sent to the processor by software to indicate that a specific event requiring attention has occurred. These interrupts allow for asynchronous processing, enabling the CPU to halt its current execution flow and execute an interrupt service routine to handle the event, before resuming normal operations.

software interrupts

current execution flow

specific routine

address the interrupt

Real-time systems are computing systems that must process and respond to inputs within a strict time frame, often in environments where timing is critical for functionality or safety. They are essential in applications such as embedded systems, industrial control, and telecommunications, where delays can lead to system failure or hazards.

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