Fast interrupt request (FIQ) is a specialized type of interrupt request, which is a standard technique used in computer CPUs to deal with events that need to be processed as they occur, such as receiving data from a network card, or keyboard or mouse actions.
[1][2] An FIQ takes priority over an IRQ in an ARM system.
A context save is not required for servicing an FIQ since it has its own set of banked registers.
FIQs are often used for data transfers such as direct memory access operations.
FIQs can be disabled by clearing the F bit in the CPSR (Current Program Status Register).