I had wrote on this subject last year and put the project down until now. I am having a problem when an external device sets its address lines to outputs while connected to the EZ-USB AN2125 chip at Port D. I an2125 goes into an unknown state. I am using the fast read and fast write on the an2125 and the fast write works just fine. When I attempt to do a fast read the the external device swithches to an output is when the an2125 loses control. Any help would be appreciated.