Im trying to:

volatile struct  sDeviceReg
{
  .
  .
  .
};

and I'm getting the error:
error: qualifiers can only be specified for objects and functions

Am I doing this wrong??

Thanks

The error means just what it says, you cab have a volatile variable or
function but not a volatile data type.

struct  sDeviceReg
{
...
};

volatile struct sDeviceReg device_instance ;


or

volatile struct  sDeviceReg
{
...
} device_instance ;


Note that in both cases it is device_instance that is volatile not
sDeviceReg. If you create other instances of this structure, they will
only be volatile if you declare them so individually.

Clifford