This intrinsic inserts a
DSB or equivalent instruction into the instruction stream generated by the compiler.
DSB instruction ensures the
completion of memory accesses.
__dsb() intrinsic is also an optimization barrier. If the target does
not support the
DSB instruction, the intrinsic behaves as an
void __dsb(unsigned int
is a numeric argument indicating the scope and access type of the barrier. See ARM C Language Extensions for more information.