How to check USB port health

Hi guys,

How can I check that my USB port on Macbook Pro is working fine. I know I can see details in system report but I want to know whether the USB port disconnect and connect every 20 seconds for example or not.

It does work fine with external storage and iPod, iPhone 4, but it does some weird stop when I'm typing with external keyboard and it does connect and reconnect my iPhone 4S.

Is there any software to find out whether it's fine or not?

Detail: MBPR with Mountain Lion.

Thanks