IO read and IO write are for IO transfer whereas memory read and memory write are for memory transfer.

In other words, there are different read-write instruction for both IO and memory. There are two separate control lines for both memory and IO transfer. IO mapped IO uses two separate address spaces for memory locations and for IO devices. This means I/O devices use the same address bus as memory, meaning that CPU. Load and Store commands are executed for reading from and writing to I/O devices, just like they are used for the memory (port-mapped has special commands for I/O). Hence, it can lessen the addressing capability of memory because some are occupied by the IO. In memory-mapped systems, the I/O device is accessed like it is a part of the memory. Therefore, the instructions used to manipulate memory can be used for IO devices too. As a CPU needs to communicate with the various memory and input-output devices (I/O) as we know data between the processor and these devices flow with the help. The same set of instructions work for both memory and IO operations. There is one set of read and write instruction lines. Possibly main advantage of Memory Mapped IO is performance, which is important to build high frequency electronic trading system. In other words, some addresses are assigned to memory while others are assigned to store the addresses of IO devices. Memory mapped IO uses one address space for memory and input and output devices. I/O devices are treated as I/O and memory as memory.īoth the devices i.e I/O and memory are treated as memory.Ĭentral signals used for I/O are IOR and LOW.Ĭontrol signals used for I/O are MEMR and MEMw.ĭata transfer is possible between accumulator and I/O only.ĭata transfer is possible between any register and I/O. VishvadeepGothi Sir has covered the IO Organization: Introduction, IO-Mapped. Difference between Programmed I/O vs Memory Mapped I/O iniatinklis2022 m. Memory mapped IO Port mapped IO Memory Mapped: address space is shared between Memory and IO I/O devices are mapped into the system memory map along with RAM and ROM. In this live lecture, you will prepare the COA2.0 for GATE CSE/IT 2022 Exam. iniatinklisMemory mapped IO addresses are treated just like any other. Compare Memory And I/O Mapped I/O For Example I/O Mapped I/P There are 2 ways in which IO Devices addressing is done.

Memory mapped io vs io mapped io