The connection and data exchange between the CPU and external devices and memory need to be realized through the interface device, the former is called the ic port, and the latter is called the memory interface.
The memory usually works under the synchronous control of the CPU, and the interface circuit is relatively simple; There are many varieties of ic ports, and their corresponding interface circuits are also different, so it is customary to say that the interface only refers to the ic port.
The function of the ic port is responsible for the realization of the CPU through the system bus ic circuit and Peripherals are linked together according to the complexity of the circuit and the device.
ic port hardware is mainly divided into two categories:
(1) ic port chip These chips are mostly integrated circuits, input different commands and parameters through the CPU, and control the related ic circuit and simple peripherals for corresponding operations, common interface chips such as timing\/counter, interrupt controller, DMA controller, parallel interface, etc.
(2) ic port control card has a number of integrated circuits according to a certain logic as a component, or directly with the CPU on the motherboard, or a plug-in inserted in the system bus slot.