* Question
Briefly describe the FIQ interrupt
* Answer
The FIQ (Fast Interrupt Request) is a high-priority, low-latency interrupt used in ARM architecture processors and certain microcontrollers. It is designed to handle time-critical or high-frequency events more efficiently than standard interrupts.
Key Characteristics of FIQ:
High Priority:
FIQ has a higher priority than the regular IRQ (Interrupt Request), ensuring it is serviced first when multiple interrupts occur simultaneously.
Faster Context Switching:
The processor allocates dedicated registers (R8–R14) for FIQ mode, reducing the need to save and restore general-purpose registers during interrupt handling, which speeds up execution.
Minimal Latency:
Due to its priority and optimized context handling, FIQ delivers lower latency, making it ideal for real-time tasks.
Use Cases:
Typically used in:
High-speed data acquisition
Real-time signal processing
Time-sensitive I/O operations
In summary, the FIQ interrupt is a specialized, high-performance interrupt mechanism intended for the most time-critical functions in embedded systems. Its priority and hardware efficiency make it ideal for minimizing interrupt response delays.
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