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.
I am a little confused. The AN2125 does not use address lines for fast transfers.
The AN2125 uses the data bus D[7..0] to access an external device during fast transfers.
Since only the D lines (and frw, fwr) are connected between the micro and the external device, why would you expect "an external device sets its address lines to outputs" to affect the micro? From what little you have said, I am infering that the external device has its own separate muliplexed address bus, that is enabled on a fast transfer. This sounds very complicated. Is there another micro or FPGA involved?
The external device is another micro. The other lines that are used are a chip select and a data ready. We are trying to debug on the EZ-USB Devloper board. Is there a conflict between the external SRAMs or could we somehow have the Options for the Target set up wrong while trying to debug using the monitor??
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