Field Name            Bits   Default Description
ROP_ENABLE            2      0x0     POSSIBLE VALUES:
                                     00 - Disable ROP. (Forces ROP2 to be 0xC).
                                     01 - Enabled
ROP                   11:8   none    ROP2 code for 3D fragments. This value is replicated
                                     into 2 nibbles to form the equivalent ROP3 code to
                                     control the ROP3 logic. These are the GDI ROP2 codes.