Post Silicon Debugging Approach for USB2.0: Case Study of Enumeration

USB forms the backbone of communication to external world. When a USB device is attached to a USB host, a sequence of interaction happens for establishing the communication channel, known as enumeration. This paper explains the enumeration process of USB2.0 in detail and discusses the challenges faced during post silicon debug of couple of issues related with enumeration. As a case study we will analyze two issues which were found during enumeration. The first issue is related to repeated enumeration in which process hangs and second is related to timeout failure.