PS QSPI max frequency fails in x4 mode
- There is a problem to read the QSPI memories at 90MHz
- The problem only happens in the read in x4 mode
- It was observed downgrading the Frequency to 50MHz the read works well
- I link here the AMD/Xilinx recommendation for QSPI (https://docs.xilinx.com/r/en-US/ug583-ultrascale-pcb-design/QSPI)
- I attach to the post also the python script used for test mtd_test.py
To conclude, apparently it seems to be a routing problem of the PCB. Also we don't get a huge benefit using 2 memories in dual parallel configuration. I suggest to move to a single memory with the same size to simplify the routing. I propose this component, similar to version 2 with double size.