USING USB SIGNALING TO TRIGGER A DEVICE TO ENTER A MODE OF OPERATION

摘要

A method of triggering a desired operating mode in a universal serial bus (USB)-compatible client device is provided. A USB-compatible client device detects that it has been coupled to a USB-compatible host device via a USB bus. The USB-compatible client device attempts to pull a data line of the USB bus high. The USB-compatible client device then ascertains that the data line remains pulled low, thereby indicating that the USB-compatible client device should enter a first mode of operation. The USB-compatible client device operates according to the first mode of operation.

主权项

1. A method of triggering a desired mode of operation in a universal serial bus (USB)-compatible client device, comprising:
detecting that the USB-compatible client device has been coupled to a USB-compatible host device via a USB bus; attempting to drive a data line of the USB bus to a logic high as a result of the detection; determining that the data line is at a logic low during the attempt to drive the data line to a logic high, thereby indicating that the USB-compatible client device is to enter a first mode of operation; and operating the USB-compatible client device according to the first mode of operation as a result of the determination that the data line is at a logic low.