Auto-Detect Polling for Correct Handshake to USB Client

摘要

An embodiment of the invention provides a method for providing power to a USB client device and polling for a correct protocol. A USB host device provides power and a first part of a first handshake determined by a first protocol. The host then monitors the client for a second part of the first handshake. When the second part of the first handshake is detected by the host, the client recognizes that power may be applied according to the first protocol. When the second part of the first handshake is not presented by the client device, the host provides a first part of a second handshake according to a second protocol. When the second part of the second handshake is provided by the client, the host the client recognizes that power may be applied according to the second protocol.