RAM writing and reading good, data not getting back to SPI link state machine correctly

INTEGRATED LOGIC ANALYZER CAPTURED RAM OUTPUT

My load transaction stored the ascending integers in the word addresses of the sector, e.g. 0001 for word 1 and 0002 for word 2. The unload transaction read the same sector back and shipped the value back on the SPI link.

While the upstream data appeared to be gibberish, the values coming from the memory interface was indeed the same ascending integers as I had written and they were properly set up in the data in field for the FIFO that would transport that result back to to normal FPGA clock domain for use by my SPI link. 

THE ISSUE IS SOMEWHERE IN THE RETURN OF THE DATA

The data is set up properly in the FIFO that transports results. I will now focus on watching the FIFO operate and judge the correctness of the data returned on the regular clock side of that FIFO. If that is good, I could still have a problem capturing that into the SPI link state machine for the outgoing byte that is sent up to the Arduino. 

I reconfigured the logic analyzers to focus upon that data I need to watch for the response FIFO and my SPI link state machine. This does cross clock domains, which means I can't watch both the data entering the FIFO and the data entering the FIFO in the same logic analyzer core. I can, however, trigger on the FIFO empty flag to at least watch each result being presented in my FPGA logic clock domain. 

QUICK RESCUE OF SOME HARDWARE

I learned of a mainframe and some related hardware that was at risk of being scrapped as a person nearby had to clear out a storage unit. He was no longer interested in restoring the system and rents for the storage space had doubled suddenly. 

Today I had a small moving business I worked with previously meet me at the storage unit and haul those boxes to my workshop before the end of October. It is an IBM Z9 BC mainframe, almost 1,700 pounds which was a beast to get rolling up and down ramps for transport, plus a 3490E tape system and some ancillary parts. The tape unit was no walk in the park either, just easy in comparison to the behemoth. 

IBM Z9 Business Class mainframe

IBM 3490E 36 track tape cartridge drives