Ideas concerning the problems listed in TEST_RHD.sh
1.) While debugging the RHA source code, I noticed a missing reset value in [RHA_TO_ZL_CONVERTER.vhd] in the process FSM_BLOCK PROCESS:
SPIMACHINE_STATE <= SM_IDLE;
This could be the cause of the extra 00000000 in the begining after the Zarlink connection was created.
2.) I changed the [RHA_TO_ZL_CONVERTER.vhd] and [RHA_Array.vhd] in the RHA case from polling to fall - through. Maybe it is a good idea to do this for the RHD too...