Re: DIY FPGA Mining rig for any algorithm with fast ROI

Regarding the question about bitstream compatibility, the answer is no, a bitstream built for VCU1525 will not work on the XUPP3R. The clock & USB UART are on different pins, so I must 'build' two versions of the bitstream, one for each card. Although the change in the code is tiny, it still takes the tools 5+ hours to re-run place & route, with multiple runs needed to get a success.

Can you inplement a double set of interfaces to support both boards by the single firmware?
BUFGMUX_CTRL can be used to select the clock signal, if clocking assignment is different.
It is probably possible to build one firmware for both board.

I get the general idea but I still have a hard time seeing how to do that with the USB-UART pins.

If the alternative serial pins are mutually unused on the other board then:
- you can transmit on both TX pins.
- enable the pull up for RX pins, because in idle state the serial lines are in high state. Then you can make a common RX signal: RX_COMMON=1'b1^RX_A^RX_B.