Removing audio from HDMI(ADV7623)

Dears,

     I am making a feature that we get HDMI source to ADV7623 input end and output to HDMI sink. Normal it comes out audio from the sink if the source contains audio. However , if I want ADV7623 acts as a DVI module(black box, which output without audio via HDMI cable). That is I want vedio output only, no audio. How to set the registers?

    I try to set the ADV7623 to DVI mode and also mute the audio. but the audio comes out to the sink also. The readback value of HDMI_MODE_RAW [IO MAP] is always set.

    How can I remove the audio from HDMI?

Thank you so much

Regards,

Jacy.