HDMI ADV7623 12 bit color Deep test

Hi,

We are doing 1080p,12 bit color deep test in HDMI ADV7623 board.

We observed the following result:

Case 1:

RX Port 6 Feet HDMI cable

TX port 6 Feet HDMI cable

The video is good in 8 bit,10 bit and 12 bit

Case 2:

RX Port 30 Feet HDMI cable

TX port 6 Feet HDMI cable

The video is good in 8 bit,10 bit and 12 bit

Case 3:

RX Port 6 Feet HDMI cable

TX port 30 Feet HDMI cable

The video is good in 8 bit,10 bit ONLY

The video is not good in 12 bit . Some noise is coming.

My questions

1) What could be the cause for video failure in 12 bit , 30 FEET Length cable?

2) is there any  TXport length limitation HDMI ADV7623?

3) Any thing needs to be check in the Hardware side.

Thanks,

Chandravel.

9840383248

Jasmin-Infotech