2 high-speed signaling eye patterns, Figure 6.3 eye pattern measurement planes, High-speed signaling eye patterns – SMSC USB3280 User Manual
Page 18
Hi-Speed USB Device PHY with UTMI Interface
Datasheet
Revision 1.5 (11-15-07)
18
SMSC USB3280
DATASHEET
6.2
High-speed Signaling Eye Patterns
High-speed USB signals are characterized using eye patterns. For measuring the eye patterns 4
points have been defined (see
). 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.
Figure 6.3 Eye Pattern Measurement Planes
USB Cable
Transceiver
Device Circuit Board
Transceiver
Hub Circuit Board
Connector
Traces Traces
A
Connector
B
TP1 TP2
TP3
TP4