Datasheet

Hi-Speed USB Host, Device or OTG PHY with ULPI Low Pin Interface

Datasheet

SMSC USB3300 47 Revision 1.1 (01-24-13)

DATASHEET

Note 6.1 SMSC does not recommend using the ExternalVbus signal qualified with the internal

VbusVld comparator.

Note 6.2 A peripheral should not use VbusVld to begin operation. The peripheral should use

SessVld because the internal VbusVld threshold can be above the Vbus voltage required

for USB peripheral operation.

A host PHY may use an active high or low fault by setting the IndicatorComplement bit [5] in the

Interface Control register. Also this implementation supports the IndicatorPassThru bit [6] in the

Interface Control register, which allows a choice of having the External Vbus input qualified (and’ed)

with the external vbus comparator output. To use the External Vbus Input the

UseExternalVbusIndicator bit [7] must be set in the OTG control register. The default is not to use this

input.

The EXTVBUS pin has a built in pull down resistor that is controlled by the UseExternalVbusIndicator

bit [7] of the OTG control register. When UseExternalVbusIndicator is set to 0 (default) the pull down

resistor is activated to prevent the pin from floating when it is unused. When UseExternalVbusIndicator

is set to 1 the pull down resistor is disconnected.

Standard Host 1 1 0 External active high power fault signal

1 1 1 External active low power fault signal

Standard

Peripheral

0 X X Internal VbusVld comparator. This should

not be used by the Link. (Note 6.2)

Table 6.10 External Vbus Indicator Logic (continued)

TYPICAL

APPLICATION

USE

EXTERNAL

VBUS

INDICATOR

PASS THRU

INDICATOR

COMPLEMENT

RXCMD VBUS VALID

ENCODING SOURCE