(ADV7611)Why ADV7611 output SCLK befor HDMI input?

Hi !

Various register settings are made after the ADV7611 power is turned on, regardless of the TMDS input.

At that time, “TRI_AUDIO, IO, Address 0x15 [4]”: 1 → 0 was also set, and 9.8437MHz SCLK was output even HDMI is not input.

This frequency is considered to be determined by the ADV7611 device, but as the description can not be found on the specifications including "UG-180.pdf".

Q1)
Why ADV7611 output this frequency?

Q2)

Is the frequency always constant at 9.8437 MHz?

Best regards

Kawa