I am running pynq-z2 with pynq version 2.7. I created a very simple bitstream to blink the LED. After I load the overlay, the board lost the network connection. The button/LED appears to behave as designed in my FPGA.
The following is the block design:
Here is the code for blink.v:
module blink(
input [3:0] btn,
output [3:0] led
);
assign led = btn;
endmodule
I load the overlay with:
from pynq import Overlay
ol = Overlay("/home/xilinx/blink.bit")
I attached the bitstream and hwh file. blink.bit (3.9 MB) blink.hwh (1.6 KB)
Is this really the root cause?
If the MIO connect is not connect, I think Vivado will not even synthesis.
I have tried empty overlay aka only PS clock and MIO before and nothing else and still network is working normally.
Yeah not totally sure what the root cause is – I have seen some similar problems before when an overlay is loaded with a badly configured PS so It would be good to see the hwh file and bit file with the PS added. But I completely agree that it might not be the issue.
@Li_Chen, when you load the overlay do you notice any messages appearing over UART?
I connected the UART. When I load the overlay, the Linux system crashed as the UART is not responding; no messages. The PL part is still working as the LED is responding to buttons.
I figured out the problem. After I added the PS, I forgot the step to add the HDL wrapper. After I added it and regenerated the bitstream, loading overlay no longer crashes Linux.