1, IO interface: the interface is the link between the host and the controlled object for information exchange.

2. Port: it is the exit of communication between the equipment and the outside world.

Second, the function is different.

1, IO interface: provides status information of I/O devices to CPU and decodes commands. Buffer the transmitted data to eliminate the "timing" or data processing speed difference between the computer and peripheral devices.

2. Ports refer to some registers in the interface circuit, which are used to store data information, control information and status information respectively.

Third, the characteristics are different.

1, IO interface: Input different commands and parameters through CPU to control related I/O circuits and simple peripherals to do corresponding operations. Timer/counter, interrupt controller, DMA controller, parallel interface and other common interface chips.

2. Port: After the connection with the port is established through system call, the data sent by the transport layer to the port is received by the corresponding process, and the data sent by the corresponding process to the transport layer is output from the port.

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