Just an update: I guess the D+ and D- are not swapped, because the communication with PC is happening
(I used a USB sniffer software to record all the packets sent and they seem to be fine). Attached is the log of the same.
usb_sniff_log.txt.zip 1.1 K
Yes, it seems there is no problem in the USB lines as the device is enumerated correctly.
As per the PMODE[2:0] line = Z1Z, you are using I2C booting with USB fallback enabled.
Please refer to the section 3 of Troubleshooting SPI / I2C Programming in FX3 – KBA94604 thread.
To check the I2C connection and whether the I2C flash is compatible with the vendor commands sent, program the RAM with the I2Cregmode example from the SDK, pass the vendor commands and check if it works.
Please let me know if any queries.
As you are using the custom board, please follow AN70707 Application Note for hardware design guidelines and check that the schematic of your board with the checklist given in the application note.