Datasheet – SMSC USB3280 User Manual
Page 19
Hi-Speed USB Device PHY with UTMI Interface
Datasheet
SMSC USB3280
19
Revision 1.5 (11-15-07)
DATASHEET
The eye pattern in
defines the transmit waveform requirements for a hub (measured at TP2
of
) or a device without a captive cable (measured at TP3 of
). The corresponding
signal levels and timings are given in table below. Time is specified as a percentage of the unit interval
(UI), which represents the nominal bit duration for a 480 Mbit/s transmission rate.
Figure 6.4 Eye Pattern for Transmit Waveform and Eye Pattern Definition
VOLTAGE LEVEL (D+, D-)
TIME (% OF UNIT INTERVAL)
Level 1
525mV in UI following a transition,
475mV in all others
N/A
Level 2
-525mV in UI following a transition,
-475mV in all others
N/A
Point 1
0V
7.5% UI
Point 2
0V
92.5% UI
Point 3
300mV
37.5% UI
Point 4
300mV
62.5% UI
Point 5
-300mV
37.5% UI
Point 6
-300mV
62.5% UI
Differential
-400mV
Differential
400mV
Unit Interval
100%
Level 2
Level 1
Point 1
Point 2
Point 4
Point 3
Point 6
Point 5
0%
0 Volts
Differential