USB接口被广泛地应用在计算机外设接口地设计中 ,尤其是嵌入式系统和穿戴计算机系统 .为了减小系统的体积 ,提高系统的集成度 ,可以利用 System On Chip技术将 USB主机控制器集成在微处理器中 ,构成片上系统 ,这就需要自行设计 U SB主机控制器的核 (Core) .本文系统地剖析了 U SB主机控制器的原理和结构 ,并针对 OHCI从系统级上给出了一个典型的 U SB主机控制器的具体实现 USB interface is widely used in the design of computer peripheral interface, especially in embedded systems and computer systems.In order to reduce the size of the system and improve the system integration, the system can use the System On Chip technology to integrate the USB host controller In the microprocessor, to form the system-on-chip, which requires the design of the U SB host controller core (Core) This article systematically analyzes the U SB host controller principle and structure, and OHCI from the system level The concrete realization of a typical U SB host controller