Uhm why would i have to write such subroutine?

The Micro doesnt care where the data is
saved...

If the micro writes to address 0x1234
and the memory reads its address pins
and read the value 0x4132 it just saves
there, and when the micro reads from
0x1234 the memory device sends the values that was stored in 0x4132.

-i tink-