【摘要】 USB OHCI根集线器的基本功能是根集线器设计的基础。由根集线器的基本功能需求确定其具体实现中采用的结构并对这种特定的实现方法加以验证是USB主机控制器根集线器设计的关键。根据USB规范和OHCI规范,根集线器在功能上划分为寄存器模块、端口状态机模块、端口接收模块、端口恢复模块以及端口多路复用器模块。下行端口在根集线器中具有核心作用,而下行端口状态机是下行端口设计中的难点,其运行机制通过状态图做了详细介绍。设计分别在虚拟仿真环境和FPGA验证平台上得到了验证,验证结果论证了设计的正确性。更多还原

【Abstract】 The basic functionality of USB OHCI root hub is the foundation of the root hub design.It is critical to determine the architecture applied in detailed implementation through analyzing function requirement of root hub and verify this specific design method.OHCI root hub can be functionally partitioned as register module,port state machine module,port receiver module,port resume module,and port multiplexer module according to USB specification and OHCI specification.Downstream port takes a core role in root hub,while the downstream port state machine is the design difficulty in the whole project.The detailed execution mechanism is illustrated through a state transition diagram.This design is validated in a specific virtual simulation environment and on FPGA verification platform sep-arately.The validation results demonstrate the correctness of the design.更多还原