Methods and devices for universal serial bus port event extension

摘要

Methods and apparatus for implementing a port management protocol which can be used to manage communication between one or more USB devices and a USB host at a distance greater than that allowed by the USB Specifications are provided. In one aspect, a method for prolonging a bus event of a USB device at least until a notification is received that a corresponding bus event has been completed by the USB host is provided; and subsequently exchanging bus traffic between the USB host and USB device upon completion of the bus event by both devices.

主权项

1. A computing device configurable to provide a downstream facing port (DFP) for allowing a USB device to communicate with a host via an upstream facing port (UFP), wherein the DFP is configured to:
prefetch a speed of the USB device by:
negotiating a speed with the USB device via a USB-compatible protocol; andallowing the USB device to enter a suspend state upon completion of the negotiation; transmit a connected message to the UFP, wherein the connected message includes an indication of the negotiated speed; transmit a signal to the USB device to initiate a reset in response to receiving a reset detected message from the UFP; and extend the reset at least until a reset done message is received from the UFP.