Write a md about a cpu having a risc unit and a dsp unit

[mike@csdn.sign.idv.tw]

Hello,
     I am going to write a machine description for a cpu having a risc
     unit and a dsp unit.
     The risc unit and dsp unit have their own register file.
     When using dsp instrcutions, the risc unit has to load the data
     from the main memory to dsp registers (using "load" instruction).
     And when the dsp unit processed the instruction, the risc unit uses
     "store" instruction to store the data back to the main memory.

     Any idea how to describe this in the machine description?

     Thanks.


Mike Wu