TMDS181: Fails to pass HDMI2.0 signal through TMDS181

Hi Team,

Could you please help us support our customer ?

Customer is using TMDS181 in pin mode. They were able to pass HDMI1.4b signal, however, HDMI2.0 signal could not go through TMDS181.

They have been investigating the register settings using EyeScan Tool and observed following cases.

Please advise us how they can solve this problem without register access.

[Case 1]
1). Disconnect HDMI cables to Source and Device.
2). Power up TMDS181.
3). Connect HDMI cables
4). HDMI2.0 Video not shown at Device side.
5). Change ADDR 0x0A [2] = "0" -> "1"
6). Video shown at Device side

[Case 2]
1). Connect HDMI cables to Source and Device.
2). Power up TMDS181.
3). Disconnect and connect HDMI both cables or either cable.
4). HDMI2.0 Video not shown at Device side.
5). Change ADDR 0x0A [2] = "0" -> "1"
6). Video shown at Device side.

[Case 3]
1). Connect HDMI cables to Source and Device.
2). Power up TMDS181.
3). HDMI2.0 Video not shown at Device side.
4). Change ADDR 0x0B [1:0] = "00" -> "11"
5). Change ADDR 0x0A [2] = "0" -> "1"
6). Video shown at Device side

[Case 4]
1). Disconnect and connect cable on Source or Device side ,after either of the case above.
2). No video shown at Device.
3). Change ADDR 0x0A [2] = "0" -> "1"
4). Video shown at Device.

* HPD is directly connected from Source and Device. TMDS181 snoops this signal.
* DDA is connected through TMDS181. They've tried Snoop connection, however, did not see any change.

Best Regards,

Kawai