what is the difference between memory mapped io and io mapped io

Memory mapped I/O is mapped into the same address space as program memory and/or user memory, and is accessed in the same way.

I/O mapped I/O uses a separate, dedicated address space and is accessed via a dedicated set of microprocessor instructions.

The difference between the two schemes occurs within the Micro processor’s / Micro controller’s. Intel has, for the most part, used the I/O mapped scheme for their microprocessors and Motorola has used the memory mapped scheme.

https://techdhaba.com/2018/06/16/memory-mapped-i-o-vs-i-o-mapped-i-o/