Philips 107P20/05H Electronic User's Manual

Contents

signaling.A hub consists of two portions: the Hub Controller and Hub Repeater. The repeater is a protocol-controlledswitch between the upstream port and downstream ports. It also has hardware support for reset andsuspend/resume signaling. The controller provides the interface registers to allow communication to/from thehost. Hub specific status and control commands permit the host to configure a hub and to monitor and controlits ports.DeviceA logical or physical entity that performs a function. The actual entity described depends on the context of thereference. At the lowest level, device may refer to a single hardware component, as in a memory device. At ahigher level, it may refer to a collection of hardware components that perform a particular function, such as aUniversal Serial Bus interface device. At an even higher level, device may refer to the function performed byan entity attached to the Universal Serial Bus; for example, a data/FAX modem device. Devices may bephysical, electrical, addressable, and logical.DownstreamThe direction of data flow from the host or away from the host. A downstream port is the port on a hubelectrically farthest from the host that generates downstream data traffic from the hub. Downstream portsreceive upstream data traffic.UpstreamThe direction of data flow towards the host. An upstream port is the port on a device electrically closest to thehost that generates upstream data traffic from the hub. Upstream ports receive downstream data traffic.UPS (Universal Power Supply)The monitor with UPS feature can work in different countries with various mains voltage.RETURN TO TOP OF THE PAGEGlossaryfile:///D|/rita/LF2/LF2/LFa1/multi_manual/english/GLOSSARY/GLOSSARY.HTM (16 of 18) [8/29/2001 2:55:48 PM]