Eval-adau1467Z selfboot without USB connected

SigmaDSP & SigmaStudio MDThommo81 Jul 20, 2021 00:00 2 replies Original on forum ↗

MDThommo81 Question

Jul 20, 2021 00:00

Hi there,

I recently upgraded our evaluation board to the EVAL-ADAU1467Z, everything is going well, except I'm a bit confused by the self-boot operation. I followed the instructions in the user manual and the self-boot appears to work, EXCEPT when the USBi is disconnected. I thought the whole point was so you could have the unit disconnected from the programming PC? Is there a way to overcome this?

Kind regards,

Mark

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JoshuaB Reply

Jul 20, 2021 00:00

Hi Mark,

When you disconnect the USBi, are you unplugging only the USB port? Try also unplugging the 10-pin ribbon cable. I think this will solve the problem.

The USBi asserts Pin 6 of the ribbon cable to logic low when the USB port is unplugged. This happens to be a /RESET signal, so the SigmaDSP appears to fail self-boot. Of course this is not ideal behavior... but the workaround is easy enough.