Following the lower half of page 6 of this PDF, I formatted a 2 GB microSD card to FAT32 filesystem using
mkfs.fat on Ubuntu and copied
main.bit from one of my projects. Then I inserted the microSD card onto my Nexys 4 DDR board, made sure the two jumpers are in the correct place (JP2 connected to
SD and JP1 connected to
USB/SD). Then I power-reset the board and saw the "BUSY" LED slowly pulsing, indicating that the board is waiting for a valid media to be inserted, according to the PDF.
Things I've tried:
- Note first: I have tried 2 sets of all hardware involved here, including the Nexys 4 DDR board (and the jumpers on it), the microSD card, the USB flash drive (mentioned below) and the USB cable.
- Formatted the microSD card in Windows 10 instead of Ubuntu
- Verified that the bitstream file is working correctly by downloading to the board via the PROG/UART micro USB port using Vivado 2018.2 software
- Regenerated the bitstream using Vivado
- Pulled another bitstream file from another project
- Renamed the bitstream file (keeping the
- Replaced microSD card with a 4 GB USB drive inserted into the USB Host port on the board (and changed JP2 to USB)
- Powered the board via a 5V phone charger
Here's what the board looks like (click to enlarge):
The microSD card is inserted in the slot on the other side so not visible in the image, as indicated by the arrow on the left. The two squares are JP2 (left) and JP1 (right), as I have correctly (I suppose) configured.
What could be a possible cause of this? How can I tell the board to load bitstream from the microSD card?