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ADV7842 HDMI audio with no input present

Question asked by Glenn on Jul 9, 2015
Latest reply on Jul 9, 2015 by mattp

I am trying to clarify the behavior of the I2S lines when no HDMI input is connected.  This thread seems to indicate that the MCLK can be set to a fixed frequency via some register settings and free run (adv7842 MCLK output).  What is the behavior of the SCLK (bit clock) and LRCLK  under this condition?  We see the clock go from the expected 48Khz to about ~153.8 kHz when the HDMI connector gets unplugged.  This screws up some audio mixing with other sources that happens downstream.  Is there a way to have a 48khz rate coming out the I2S when no HDMI connector is connected?

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