Describes implementation-defined aspects of the ARM C compiler and C library relating to qualifiers, as required by the ISO C standard.
An object that has a volatile-qualified type is accessed as
a word, halfword, or byte as determined by its size and alignment.
For volatile objects larger than a word, the order of accesses to
the parts of the object is undefined. Updates to volatile bitfields
generally require a read-modify-write. Accesses to aligned word,
halfword and byte types are atomic. Other volatile accesses are
not necessarily atomic.
Otherwise, reads and writes to volatile qualified objects
occur as directly implied by the source code, in the order implied
by the source code.