StarTech.com USB6N1DOCKGB, Руководство пользователя

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The USB high
•
-speed signaling bit rate is 480 Mb/s.
The USB full
•
-speed signaling bit rate is 12 Mb/s.
A limited capability low
•
-speed signaling mode is also defined at 1.5 Mb/s.
USB 2.0 host controllers and hubs provide capabilities so that full-speed and
low-speed data can be transmitted at high-speed between the host controller and the hub,
but transmitted between the hub and the device at full-speed or low-speed. This capability
minimizes the impact that full-speed and low-speed devices have upon the bandwidth
available for high-speed devices.
The low-speed mode is defined to support a limited number of low-bandwidth
devices, such as mice, because more general use would degrade bus utilization.
Abbreviations
：
kb/s
Transmission rate expressed in kilobits per second.
kB/s
Transmission rate expressed in kilobytes per second.
Mb/s Transmission rate expressed in megabits per second.
MB/s Transmission rate expressed in megabytes per second.
Low-speed
USB operation at 1.5 Mb/s. See also full-speed and high-speed.
Full-speed
USB operation at 12 Mb/s. See also low-speed and high-speed.
High-speed
USB operation at 480 Mb/s. See also low-speed and full-speed.
Hub
A USB device that provides additional connections to the USB.
Upstream
The direction of data flow towards the host. An upstream port is the port
on a device electrically closest to the host that generates upstream data
traffic from the hub. Upstream ports receive downstream data traffic.
Downstream
The direction of data flow from the host or away from the host. A
downstream port is the port on a hub electrically farthest from the host
that generates downstream data traffic from the hub. Downstream ports
receive upstream data traffic.
Device
A logical or physical entity that performs a function. The actual entity
described depends on the context of the reference. At the lowest level,
device may refer to a single hardware component, as in a memory
device. At a higher level, it may refer to a collection of hardware
components that perform a particular function, such as a USB interface
device. At an even higher level, device may refer to the function
performed by an entity attached to the USB; for example, a data/FAX
modem device. Devices may be physical, electrical, addressable, and
logical.
When used as a non-specific reference, a USB device is either a hub or
a function.
Driver
When referring to hardware, an I/O pad that drives an external load.
When referring to software, a program responsible for interfacing to a
hardware device, that is, a device driver.
Port
Point of access to or from a system or circuit. For the USB, the point
where a USB device is attached.
Host
The host computer system where the USB Host Controller is installed.
This includes the host hardware platform (CPU, bus, etc.) and the
operating system in use.