GATE CSE 1987 | Question: 2b

Question

State whether the following statements are TRUE or FALSE:

Data transfer between a microprocessor and an I/O device is usually faster in memory-mapped-I/O scheme than in I/O-mapped -I/O scheme.

Comments

this might help

https://www.geeksforgeeks.org/difference-between-memory-mapped-io-and-io-mapped-io-with-reference-to-8085-microprocessor/

memory mapped is fater.

Answer 1

True
it will take extra time in IO mapped IO because of control signal.

Answer 2

Answer is false as I/O mapped-I/O scheme is hardwired to the processor and its faster than mmio scheme.

Comments

Given answer is wrong.Memory mapped is faster than IO mapped.

source -:https://en.wikipedia.org/wiki/Memory-mapped_I/O

Answer 3

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