USBcables
Forfull-speed andhigh-speedc onnections,USB 2.0 specifications allow two ty pes of cable
assemblies:
las tandarddetachablecable that is t erminatedon oneend with a Series-A plug, and terminated
onthe opposite end with a Series-B plug
lac aptive cablethat is terminatedon one end with a Series-A plug,and has a vendor-specific
connectionon the oppositeend for the peripheral
las tandarddetachablecable that is t erminatedon oneend with a Series-A plug, and terminated
onthe opposite end with a Series-B plug
lac aptive cablethat is terminatedon one end with a Series-A plug,and has a vendor-specific
connectionon the oppositeend for the peripheral
IM P O R T A N T
Any othercable assemblies are prohibited.
Prohibitedcable assemblies
USB 2.0 specifications prohibits pecific cable assemblies. Prohibitedcable assemblies may work in
somes ituations, but they cannotbe guaranteedto work in all instances.
An exampleof a prohibitedc ableis the “extensionc able.”This ty peof c ableassembly has a Series-A
plugand a Series-A receptacleor a Series-B plugand a Series-B receptacle. This “passive”ext ension
cableallows y out o connectmultiple cable segments, possibly exceeding the maximumpermissible
cablelength.
Anotherexample of a prohibitedcable is one with both ends terminatedin either Series-A plugsor
Series-Breceptacles, allowing two upstream ports ortw o downstreamdevices to be connected
together.
AP P E N DI X A
USB2.0 specification primer
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