Your may have some problems if you try to call your subroutines Read_CReg() and Read_RReg() from the interrupt context becasue this will step on your mainline register set 0. The interrupt thread you have using register set 1. The subroutines named above called from the interrupt context know not to save any registers used in the subroutines. If the mainline context had these in use at the time they get trashed by the interrupt coming along.

Michael Karas