I thought people would be interested in this:
'Super-secret' debugger discovered in AMD CPUs
http://www.theregister.co.uk/2010/11/15/amd_secret_debugger/
Please let me know if you get it working.
here is the real meat from that article
password: 9C5A203A
http://www.woodmann.com/collaborative/knowledge/index.php/Super-secret_debug_capabilities_of_AMD_processors_!
http://cbid.softnology.biz/html/undocmsrs.html