INx Commands

INx commands perform an I/O input from the source and place the result 
into the destination. Width can be byte, word, or doubleword.  The syntax 
is as follows: 

INB( destination, source);
INW( destination, source);
INDW( destination, source);

<destination>  ::= <register>
<source> ::= <constant>  |  <pio variable>