4.3.10.6 Io_low Attribute
The io_low(address)
attribute is similar the
io(address)
attribute, but additionally it informs the
compiler that the object lies in the lower half of the I/O area, allowing the use of
cbi
, sbi
, sbic
and
sbis
instructions. This attribute also has an
io_low
form, which does not specify an address.