I'm using SM502 device in a processor...SM502 has variety of device like USB, display and others...The thing is that the SM502 has only one interrupt to the host bus...

The problem I am facing is that I cant able to get the interrupt out of SM502 device for USB especially, even though I affected the necessary registers of USB controllers in SM502. I also probed the output line through Scope which results negative.

What is the reason for me to not getting Interrupt ????