USB3280 Datasheet, PDF (18/42 Pages) SMSC Corporation – Hi-Speed USB Device PHY with UTMI Interface

6.2
High-speed Signaling Eye Patterns
Hi-Speed USB Device PHY with UTMI Interface
Datasheet
High-speed USB signals are characterized using eye patterns. For measuring the eye patterns 4
points have been defined (see Figure 6.3). The Universal Serial Bus Specification Rev.2.0 defines the
eye patterns in several ‘templates’. The two templates that are relevant to the PHY are shown below.
TP1 TP2
TP3 TP4
Traces
Transceiver
A
Connector
Hub Circuit Board
USB Cable
Traces
B
Connector
Transceiver
Device Circuit Board
Figure 6.3 Eye Pattern Measurement Planes
Revision 1.2 (10-27-06)
18
DATASHEET
SMSC USB3280