DM505 :Difference between XDM505 and DM505

Part Number:DM505

I want to know difference between XDM505 and DM505.

I use XDM505XXBABF and DM505MRBABF chipset.

As I know, the libraries of two chips are the same. 

But, I think that two chips are operated.

If you know anything about this, please let me know.

Thank you.