SNIU028D February 2016 – September 2020 UCD3138 , UCD3138064 , UCD3138064A , UCD3138128 , UCD3138A , UCD3138A64
FIQ is similar to IRQ. The following are a few differences that may make FIQ faster:
Note that FIQ holds the last interrupt vector (Table 14-5). So the FIQ service routine can be placed immediately after the interrupt vector table, thus saving a branch instruction execution time.