Texas Instruments OMAP5912 Reference Manual page 1453

3.17 Device States Attached/Unattached Handler
Figure 24. Attached/Unattached Handler
Attached/unattached
handler
DEVSTAT.ATT
= 0?
Yes
Set IRQ_SRC.DS_CHG
to clear the interrupt.
Inform application
that the device has
been disconnected
from a USB host
or hub.
End of attached/
unattached handler
3.18 Device State Configuration Changed Handler
SPRU761A
Device attached/unattached interrupts occur when the device detects that its
VBUS has changed. System software can disable the USB device controller
clock after IRQ_SRC.DS_CHG is cleared after servicing an unattached
interrupt. Disabling
IRQ_SRC.DS_CHG is cleared can result in improper functionality for future
USB device controller interrupts (see Figure 24).
No
=1
When a configuration changed interrupt occurs, the USB device has received
a set configuration operation. When this occurs, the configuration-changed
handler performs the operations shown in Figure 25.
the USB device
Inform application
that the device has
been connected to
a USB host or hub.
Must be done prior to remove the
LH clock
The device can now be put in
deep sleep (LH clock can be
shutoff).
Universal Serial Bus (USB)
USB Device Controller
controller clock before
Set IRQ_SRC.DS_CHG
=1
to clear the interrupt.
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