Answer : True
I/O mapped I/O or Port I/O or Isolated I/O : I/O devices have a separate address space from general memory, either accomplished by an extra "I/O" pin on the CPU's physical interface, or an entire bus dedicated to I/O. Because the address space for I/O is isolated from that for main memory, this is sometimes referred to as isolated I/O.
One merit of memory-mapped I/O is that, by discarding the extra complexity that port I/O brings, a CPU requires less internal logic and is thus cheaper, faster, easier to build, consumes less power and can be physically smaller. Since any general-purpose register can send or receive data to or from memory and memory-mapped I/O devices, memory-mapped I/O uses fewer instructions and can run faster than port I/O.
Source : Wikipedia: Memory-mapped I/O