USB workaround

[Frida]

I have here two pic. The first shows when I power up and missing the USB, and after reset it finds the USB.

The second shows the result after I placed the jumper. Both powered up, and after reset it shows that USB is there.

Both studies started by first putting power on and wait for the login screen, then press the reset.

Look at line 154.

[FHuettig]

Thanks Frida, that's exactly what I see with some boards I have, just swapped from the way you have them (my pre-reset is your post-reset and v.v.).

If you are happy using your board with your mod then that's great, you've only given up the use of that LED for other purposes. If you don't want to give up the LED then you're welcome to apply for an RMA and you'll get a board that at least boots properly on power-up, though perhaps not on reset. Same goes for perles, Sean S and anyone else.

[Sean S]

I tried this fix last night. It did not fix my issue. To be clear - I have never seen USB working on my board.

I would be keen to hear if this has worked for anyone else.

Thanks,
Sean

[perles]

I'm traveling tomorrow once I'm back I'll try this fix in my board. I'll post here my results.

[Frida]

[theover]

I'm glad people are working on the USB problem, Mine is a gamble at startup, a long usb cable helps the odds the interface gets recognized during startup, and a reset brings it on, but that may corrupt the card data.

I've never looked at it, but I suppose the starting up of the bigger chips and filling the various decoupling caps (up to a number of 100 uFs) costs the stepdown chips quite some startup surge, and there is no real power sequencing (except that could be done by one of the connectors), so it may be related to that , too.

T.

[FHuettig]

@SeanS & @perles and anyone else who wants to try this, please be aware that for this to work you have to have a board with a flash image that turns on CR10 at boot time. If you only have one green LED when the board boots then this will not work, USB will be held in reset forever as will the Ethernet. The kickstarter boards did NOT have this feature, the 7010-based boards do have it as well as some recent boards and all boards going forward.

@Frida, I'll take a closer look and for a long time now I've wanted to snoop the ULPI with a logic analyzer so I'll try to do that too. Xilinx does intend this interface to be used the way we are using it, for example the Zedboard, plus those pins including STP should be pulled high until the pin-muxing has been sorted out and they become a real ULPI interface. However what you describe is very plausible.

[Sean S]

Hi

Yes, I came to the same conclusion. CR10 never lights up on my board. I am using the latest image but I don't think it has an FPGA image that supports toggling the user led.

Can you please share your image if it supports the 7020.

Thanks,
Sean

[Frida]

Mine is only 7010

[FHuettig]