D+ signal failed to return to low level | Cypress Semiconductor
D+ signal failed to return to low level
Hi, in our system, we used 68013A as the USB controller. Occationally the operating system (windows XP) failed to recognize the USB device after the USB cable was connected, that is, in the device manager, no USB device was found. And we found out in this situation, D+ signal remained in high level(about 3.1V) for a much longer time than the normal situation.
Could you please tell me what are the probable cause to this problem? Why D+ signal remained in high level? And how to solve this problem?
Thanks very much.