This is a trivial read-only port.
The register EIND is used in controllers with more than 64K words of Program Memory, to access the whole program space.
EIND is used by instructions EICALL (Extended Indirect CALL) and EIJMP (Extended Indirect JuMP). In order to get to the desired program space address, these instructions concatenate EIND with the Z register (EIND:Z).
In controllers with less than 64K words of Program Memory, this register is not used.
The EIND register can be written only through the IOF general read and write port.
No instruction explicitely requests to write this register.
