SMSC USB3280 Manual do Utilizador descarregar pdf (Página 19)

Hi-Speed USB Device PHY with UTMI Interface

Datasheet

SMSC USB3280 19 Revision 1.5 (11-15-07)

DATASHEET

The eye pattern in Figure 6.4 defines the transmit waveform requirements for a hub (measured at TP2

of Figure 6.3) or a device without a captive cable (measured at TP3 of Figure 6.3). 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 Volts

Differential

1 2 ... 14 15 16 17 18 19 20 21 22 23 24 ... 43 44

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SMSC USB3280 Manual do Utilizador Página 19