Texas Instruments OMAP5912 Reference Manual page 1512

USB OTG Controller
Table 69. OTG Interrupt StatusRegister (OTG_IRQ_SRC) (Continued)
Bit Name
12 A_REQ_TMROUT
11 A_SRP_DETECT
10 B_HNP_FAIL
220 Universal Serial Bus (USB)
Description
A-device request time-out interrupt status. This bit reflects the status of
the A_REQ_TMROUT interrupt. This interrupt occurs when the
OMAP5912 OTG controller state machine acts as a default-A dual-role
device and transitions from state a_wait_bcon to a_wait_vfall because
the state machine did not see an attach. This interrupt can occur if
system software attempts to power up an OTG link when the cable is not
attached at both ends, or if the device at the far end of the cable does
not provide a pullup resistor.
0: A-device request time-out interrupt is inactive.
1: A-device request time-out interrupt is active.
This bit is cleared either by writing a 1 or by soft reset or hardware reset.
This bit has no effect when OTG_SYSCON_2.OTG_EN is 0.
A-device SRP detection interrupt status.This bit reflects the status of
SRP detection when the OMAP5912 OTG controller acts as an OTG
default-A device. When the OTG controller sees a valid and enabled
SRP method, this interrupt is generated. SRP is not detected if
OTG_CTRL.OTG_BUS_DROP is 1 or if OTG_CTRL.A_BUSREQ is
active.
0: SRP detection interrupt is inactive.
1: An SRP has been detected, using the VBUS pulsing and/or data
pulsing detection mechanism.
This bit is cleared either by writing 1 or by soft reset or hardware reset.
This bit has no effect when OTG_SYSCON_2.OTG_EN is 0.
B-device HNP failed interrupt status. This bit reflects interrupts that are
generated when the OMAP5912 OTG controller acts as an OTG
default-B device and an HNP it attempts to issue fails. This interrupt is
generated when the default-A device does not enable its D+ pullup in
response to the HNP request within the allotted time. This interrupt is
also generated if the OMAP5912 OTG controller acting as a default-B
device issues HNP, but the default-A device issues a USB resume. A
third instance where this interrupt can be generated is if OMAP5912
acting as a default-B device issues an HNP request, but VBUS fails
before completion of the HNP.
0: B-device HNP failure interrupt is inactive.
1: B-device HNP failure interrupt is active.
This bit is cleared either by writing 1 or by soft reset or hardware reset.
This bit has no effect when OTG_SYSCON_2.OTG_EN is 0.
SPRU761A