Analog Devices ADSP-BF53x Blackfin Reference page 620

Instruction Overview
Example
sti r3 ;
Also See
Disable Interrupts
Special Applications
This instruction is often located after an
execute after a wake-up event from the idle state.
16-16 ADSP-BF53x/BF56x Blackfin Processor Programming Reference
instruction so that it will
IDLE