Table of Contents
Advertisement
USB OTG Controller
occur. When OTG transceiver interrupts occur, system software must query
2
the OTG transceiver status using I
C and update the OTG controller registers
as appropriate.
Some system applications require that the USB Mini_AB receptacle can be
connected to downstream non-OTG USB devices, such as mice, keyboards,
or printers. In such cases, the USB OTG specification allows use of a converter
cable with a mini-A plug on one end and a standard type-A receptacle on the
other end. The USB OTG transceiver, which is capable of supplying the
amount of VBUS current required by the USB OTG specification, might not be
able to meet the VBUS current supply requirement of the USB specification.
In such cases, it is necessary to provide some alternate VBUS source that
meets the USB specification requirements.
Pin Group 0 OTG
The integrated USB transceiver on OMAP5912 USB pin group 0 does not
provide the functionality specific to OTG transceivers. To implement an OTG
dual-role device using OMAP5912 USB pin group 0, an external OTG
transceiver is necessary to provide that additional functionality. In such a
system, the external OTG transceiver provides the VBUS detect and drive, D+
and D- pullup and pulldown, and ID detection features, while the OMAP5912
integrated USB transceiver provides the D+ and D- signal drive and receive
functions (see Figure 59).
SPRU761A
Universal Serial Bus (USB)
265
Advertisement
Chapters
Table of Contents
