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ADAU1701 in selfboot mode and I2C communication

Question asked by dimitrisTymph on Jun 4, 2015
Latest reply on Jun 4, 2015 by dimitrisTymph

Hi forum,


I have a board with ADAU1701 in standalone mode using an external EEPROM.

The selfboot pin of the ADAU1701 is hardwired pulled-high. In this case according to the datasheet the ADAU1701 will act as the I2C master.

On this board we recently added an MCU and other modules such as digital amplifiers.

Now the MCU is trying to communicate using I2C protocol with the rest of the modules but communication is not possible.


Could it be that the selfboot mode of the ADAU1701 for some reason keeps the I2C bus non-idle for another master to use?

If yes, what is the way around this problem? If let's say, I am not interested in communicating anything between the MCU and the DSP or the EEPROM after initial bootup, will pulling the selfboot pin low free up the I2C bus for my MCU to use and communicate for the amplifier?


the information I am getting from the datasheet is a bit ambiguous.

It is stated that I can still communicate through I2C with the DSP after the DSP bootsup in selfboot mode but at the same time it is stated that in selfboot mode the I2C address pins of the DSP are ignored.

I also found this thread with some relevant information: but I am still not sure what is the easy way around this problem.

Would pulling the selfboot pin low after bootup or possibly cutting off and isolating I2C lines of the DSP and the EEPROM from the rest of the I2C devices help?