Q: The customer connects its Modem with USB interface (client) to TPS65950 USB (Host). When system is in sleep, and there is an incoming call, the modem needs to wake up TPS65950 + OMAP3430. Could Modem wake up TPS65950 via the USB bus?
A: We have two modes available for SRP :
1.VBUS pulsing : On changes in VBUS, interrupt information can be passed through ULPI interface to OMAP in USB suspend mode.[ULPIDATA3 pin]
TPS65950 can provide interrupt information to OMAP. It will be upto OMAP to process this interrupt and wake up the system.
2. Dp-Dm Pulsing :
DP-DM information can be passed asynchronously to link controller of OMAP when system and USB is in sleep.
So now it depends on link controller in OMAP if it can wakeup TPS65950 through this information.
In both the cases above, it depends on how OMAP takes action to wake up the system. TPS65950 does not wake up due to the pulsing.