Method and apparatus for usb/otg connection providing active hnp requests and saving host power

A device comprising:

• a) a processor coupled to a universal series bus (USB) bus including a Vbus, data lines D+ and D−, and a ground line;
• b) a storage device coupled to the processor and providing software executable by the processor;
• c) a power supply capable of supplying Vbus with at least two different voltage levels;
• d) control circuits coupled to the processor and the USB bus, the control circuits responsive to the processor for controlling the transfer of information to and from the USB device, wherein the processor is configured to:
• (i) send a message via the USB bus notifying a transceiver of a proposed lowered Vbus voltage for saving power, and
• (ii) receiving a response from the transceiver indicating acceptance or non-acceptance of the lowered Vbus voltage.

A device, comprising:

• a) a processor coupled to a universal series bus (USB) bus including a Vbus, data lines D+ and D−, and a ground line;
• b) a storage device coupled to the processor and providing software executable by the processor;
• c) control circuits coupled to the processor and the USB bus, the control circuits responsive to the processor for controlling the transfer of information to and from the USB device, wherein the processor is configured to:
• (i) receive a message from a transceiver via the USB bus notifying the USB device of a proposed lowered Vbus voltage for saving power, and
• (ii) providing a response to the transceiver indicating acceptance or non-acceptance of the proposed lowered Vbus voltage.