Hi Matt,
Yes, I knew the settings to that register 0x4B in TX map. I did set 0x4B in TX map with value 0x80 to unmute video and 0x40 to mute the video, they were working well if adv7626 did not receive AVMUTE ON in the last GCP received, which the read only register 0x04 in HDMI Rx map was read back as 0x23.
But it was not the case if the value of the read only register 0x04 in HDMI Rx map was 0x63. If the read back AVMUTE status was ON in the last GCP received (0x04 = 0x63), ADV7626 couldn’t unmute the video with the setting in register 0x4B being changed to 0x80 in TX map.
Thanks,
Leon