title: Usage of Volatile in case of Memory mapped Devices?
body: <p>Following link  says that "Access to device registers is always uncached"</p>
  
  <p><a href="http://techpubs.sgi.com/library/dynaweb_docs/hdwr/SGI_Developer/books/DevDrvrO2_PG/sgi_html/ch01.html" rel="nofollow">http://techpubs.sgi.com/library/dynaweb_docs/hdwr/SGI_Developer/books/DevDrvrO2_PG/sgi_html/ch01.html</a></p>
  
  <p>My Question is do we ever need volatile when access to device registers which is memory mapped?</p>