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6174B–ATARM–07-Nov-05
AT91FR40162S Preliminary
rupt to whatever was being executed before, and of loading the CPSR with the SPSR,
masking or unmasking the fast interrupt depending on the state saved in the SPSR.
The F bit in the SPSR is significant. If it is set, it indicates that the ARM core was just about to mask FIQ
interrupts when the mask instruction was interrupted. Hence when the SPSR is restored, the interrupted
instruction is completed (FIQ is masked).