User's Manual

© SENSITECH INC. CONFIDENTIAL – CONTROLLED DOCUMENT Page 46 of 83
A Carrier Corp. Company
PART NUMBER T82002163
REV A
Figure 12-16. Host Port 2 OTG Transceiver
Interface to External OTG Transceiver
In the case where the user does not use the internal OTG transceiver, the UDC contains control,
status, and interrupt registers to provide seamless interfacing to external transceivers. External
transceivers can be used to provide D+, D–, and Vbus driver to the USB. In this mode, the USB D+
and D– signals are output through GPIO pads with UP2OCR[SEOS] used to control multiplexors
to select between UDC and USB host controller D+, D–, and transmit enable signals. In addition,
the USB Port 2 Output Control Register (UP2OCR) provides the external transceiver suspend
(EXSUS) and external transceiver speed (EXSP) control output bits, and the external transceiver
interrupt input to interface to the external transceiver. Figure 12-17 illustrates the OTG connection
to an external transceiver.
Figure 12-17. Connection to External OTG Transceiver