Is there any need for the USB_VBUS input pin to be used in an application where the 6446 is acting as the USB host controller? Our application has two physical USB connectors, one for a USB host, one for a USB device connection. The board is configured at power up to be one or the other (i.e. it is not switching dynamically from one connector to the other).
For device operation, VBUS from the connector needs to go to the 6446 so that it can sense when the bus is alive. When the 6446 is acting as a host though, VBUS at the USB connector is a source of +5V power output so is there any need in that situation for the 6446's USB_VBUS input pin to reflect the state of the VBUS that it is controlling?
If the 6446 does not need to know about VBUS when acting as a host, then VBUS from the USB device connector can simply be connected directly to the 6446's USB_VBUS input pin. If for some reason it does need to sense VBUS as an input while operating as a USB host, then one would need to mux the VBUS from the host and device connectors before sending it to the USB_VBUS input on the 6446.
KJ
