I had FreeDSP PCB soldered recently and for the last two days I've been struggling to make it work. FreeDSP basically consists of ADAU1701 DSP, 24LC256 EEPROM, 12 MHz oscillator, IO circuits and Arduino Nano that transfers firmware from PC to EEPROM and vice versa.
The problem is, ADAU1701 seems to ignore the firmware located at the EEPROM and doesn't pass anything to the outputs. I have a multimeter and Hantek 6022be oscilloscope and I'd like to check if anything haven't been burnt during soldering and testing.
What's done so far:
All pins that should be driven to ground of 3.3v are fine.
Current consumption of powered ADAU1701 is 106 mA (quartz enabled) or 60 mA (quartz disabled). The numbers fall in normal range from datasheet.
Firmware can be written to EEPROM and can be read by Nano.
Writing to EEPROM was accidentally done with 4V signals instead of 3.3V. 4V is an absolute maximum for IO as per ADAU1701 datasheet. Was it able to damage the DSP?
Pins 13 (1.8V digital supply) and 14 (general purpose IO) were short-circuited for some time. Was it able damage the DSP?
Should I be able to verify the quartz using the oscilloscope? Some signal is present, but it's pretty much random.