15.2.1.1 FSR DFM Read

DFM is accessed by loading the FSRxH:FSRxL register pair with the address to be read and loading bits [7-4] of the FSRxH register with a value of ‘0111’. When a MOVIW instruction, or any instruction that accesses INDFx, is executed, the value loaded into the FSRx register pair points to the location in program memory to be accessed. If the FSRx register pair points to an unimplemented address location, the read will return ‘0’.