operating system - what is the difference between memory mapped io and io mapped io -

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pls explain difference between memory mapped io , io mapped io

on x86 there 2 different address spaces, 1 memory, , 1 i/o ports.

the port address space limited 65536 ports, , accessed using in/out instructions.

as example, video card's vga functionality can accessed using i/o ports, framebuffer memory-mapped.

other cpu architectures have 1 address space. in architectures, devices memory-mapped.


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