ADAU1701 in self-boot mode --- mistake in my board design

Having made a mistake in my board design, I'd like to figure out whether I can (reasonably easily) get around it and make it work.

As indicated in the subject, I'm using the ADAU1701 with an external EEPROM for self-boot.  The circuit is similar to the ADAU1701 mini evaluation board, so I will program the ADAU with a USBi from SigmaStudio.

The mistake I made is that I placed a chip that is driving the RESET line  (without jumper or switch to selectively disconnect it).  The RESET line (the one that goes to the ADAU1701, labeled AUDIO_RESET in the schematic, shown below) is being held at logical 0.  The one that comes from the USBi  (labeled AVR_RESET in the schematic), at this point has absolutely no effect --- it is connected to the RESET pin of an AVR microcontroller, with a 10k pullup.

SigmaStudio cannot connect to the board to download the compiled model, or save latest compilation to EEPROM.  In either case, it "freezes" and when interrupted it reports it could not connect.

I am supplying power to the board  (separately --- a 12V input goes to a 3.3V DC/DC switching regulator).  Those 3.3V go to the ADAU1701 and to the EEPROM.

Below are the relevant sections of the schematic --- the connections to the USBi and the related ADAU1701 pins.

Question #1:  should it work, with the ADAU1701 RESET line being held to 0  (active) ??
Question #2:  any suggestions to get around the problem?


ADAU1701 to USBi connections

ADAU1701 connections

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  • Looks like I may have solved the problem --- what I should have done in the first place was to place a jumper between the pin that drives the AUDIO_RESET signal, and the ADAU;  so, it occurred to me that the easiest thing to try was based on that:  I just cut the trace (fortunately it is on the board's top layer), and SigmaStudio could save the latest compilation to EEPROM.  (now I just need to put a small blob of solder to re-connect it)

    I haven't verified that the whole thing works (I don't have the necessary equipment here --- will try it tomorrow at the office), but this ia definitely a good sign!