Texas Instruments OMAP5912 Reference Manual page 1556

USB OTG Controller
Table 78. Signaling Between USB Controller and 4-Wire Unidirectional USB
Transceiver Using VP/VM Signaling (Continued)
Logical Sig- OMAP5912
nal Name Pin Direction
SPEED Output
SUSPEND Output
4.6 USB OTG External Connectivity
264 Universal Serial Bus (USB)
Transceiver
Pin Direction
Input
Input
OMAP5912 does not support 4-wire bidirectional signaling using DAT/SE0
signals.
To provide USB OTG connectivity, a dual-role device system that provides a
USB OTG controller must implement certain features. These features include
a USB mini-AB receptacle, VBUS monitoring and control, transient
suppression, ID monitoring, controllable D+ and D- series, pullup and
pulldown resistors, and a D+ and D- driver/receiver. USB OTG transceivers
that implement many of these features are commercially available.
Some USB OTG transceivers implement a 6-wire connection to the OTG
controller, whereas others require only 4 wires or 3 wires. The OMAP5912
device must be properly configured to support the signaling required by the
attached transceiver.
Many OTG transceiver control and status functions are provided using I
registers. This reduces the number of connections between the OTG
transceiver and the OTG controller. OTG transceiver I
variety of functions, including D+ and D- pullups, D+ and D- pulldowns, and
the VBUS output. OTG transceiver I
including status of the VBUS and ID pins and interrupt conditions.
The typical OTG transceiver provides an interrupt output to the processor. This
interrupt informs the processor when VBUS state changes, when ID state
changes, or when any number of other transceiver-dependent conditions
Description
Determines transceiver D+, D- output characteristics.
0 = Low speed
1 = Full speed
2
Transceivers with I C interfaces can implement this
functionality as a control bit rather than a pin.
Controls transceiver power-down modes.
0 = Active mode
1 = Low-power mode
2
Transceivers with I C interfaces can implement this
functionality as a control bit rather than a pin.
2
C registers provide transceiver status
2
C
2
C registers control a
SPRU761A