Whether users could write the memory space in the Peripheral Frames which is not occupied by registers?

Dear engineers,

                       Thanks for your time! I note that in 28335, some space in Peripheral Frames are not occupied by registers. For example, in Peripheral Frame 3, the McBSP-B registers occupied the memory from the address 0x5040--0x507F, while ePWM1 registers occupied the memory from the address 0x5800--0x583F.  And no registers are on the address 0x5080--0x57FF. So can we use this section for other purposes?

                 Thanks a lot!

                                                                                                                                                Tony Chopper