APPARATUS AND METHOD FOR DETECTING HIGH SPEED USB DEVICE

摘要

An apparatus and method for detecting when a high-speed USB device has been connected on a USB data line ( 12 ). The detection is achieved by detecting the occurrence of a full-speed idle condition and single ended zero (SE0) condition and at least two edges of a chirp sequence at 400 mV on the USB data line ( 12 ). Thus, the monitoring and differentiation between mixed said low speed and said full speed USB data is allowed which enables a USB keystroke recording apparatus ( 14 ) to ensure that keystroke data is not missed.