What is a physical IO ports?

Question

Iron

Do I understand correctly that IO potrs perform the function of transferring information over the bus to the register of the device and also reading from it? And filling the bus with the necessary bits falls on the processor when we call out dx, Al (for example). Correctly ?

Answer 1

Do I understand correctly

Correctly.

Answer 2

Generally speaking, it depends on the architecture. For example, for ISA and PCI - the answers may differ.
The simplest answer is for ISA:
*86 processor IN/OUT commands - send a request to the bus, similar to a request to memory. Those. an indication is given to the bus that this command is being executed; Well, the address (port number). Further - all devices on the bus (disk controller, network card) hear this request; and the one that is configured to work with this port is responsive. If this is an IN command, then the device issues an appropriate response to the bus; if OUT - then receives data from the processor. And to what parameter it corresponds - the device decides itself.
You misunderstand the meaning of the terms. "IO potrs" are not devices, they cannot "perform a function". And yes, that's about right.