Content originally posted in LPCWare by suckfish on Fri Jan 17 17:53:00 MST 2014
Hi,
Those bits are documented as 'Reserved' and value 0. Which means don't use them, always write as zero when you set other bits at the same address.
The actual hardware implementation of a 'reserved' bit might be any of:
* unused;
* for testing only;
* an unsupported function that is present but not working in the hardware;
* intended for a function that is not actually implemented in this particular device;
* a magic supa-dupa thingy that they only want people buying more expensive devices to use;
Incidently, peripherals on ARM processors are often designed by ARM also. You may or may not find further documentation about the peripheral on ARMs website.
