explain
It is called I/O interface for short. It is a channel for computers to exchange information with the outside world. One end of the interface is the system bus or local bus of the computer, and the other end is connected with various peripheral devices. The interface circuit receives commands and parameters from the host, provides status and interrupts to the host, and executes data input and output transmission between the host and peripheral devices. The host usually reads and writes a set of address registers to complete the command, parameter setting and status recovery of the interface circuit.
To complete data transmission, the interface provides data buffer and data width conversion functions. For low-speed peripheral devices, the host can understand the interface working process by querying the interface status or responding to the interface interruption, and complete the data exchange with the peripheral devices through the data registers in the read/write interface.
For high-speed peripheral devices, the interface circuit uses direct memory access (DMA) to implement the direct data transfer between peripheral devices and memory, and between peripheral devices. During the data transfer, the central processing unit (CPU) is not required to participate, thus improving the transmission efficiency. If the interfaces of different computer systems are connected to different buses, the interface circuits are also different. Different computer systems with the same bus can use the same interface circuit. [1]
