USB2.0 Hub事务转换器的工作机理

Mechanism of USB2.0 Hub Transaction Translator

USB通用串行总线是新一代标准接口总线。与USB1.0版本不同 ,USB2 .0不仅支持低速(1.5Mbps)和全速 (12Mbps)外部设备 ,还支持高速 (480Mbps)外部设备。为了将全 低速设备对高速设备可用带宽的影响减到最小 ,USB2 .0提供了一种机制 ,该机制支持在Hub连接的是全 低速设备的情况下 。

Universal Serial Bus(USB) is a new generation of the standard peripheral interface bus. Different from USB 1.0, USB2.0 adds a third transfer rate of 480Mbps to the 12Mbps and 1.5Mbps originally defined for USB. USB2.0 provides a mechanism that supports full-/low speed devices connected the hub, while transmitting all device data between the host controller and the hub at high-speed. The mechanism minimizes the impact that full /low speed devices have upon the bandwidth available for high speed devices.