TMDS181: Input and output performance of TMDS181

H.Tamiya

Do you have a copy of the HDMI1.4b spec? Both the 1.48Gbps input mask opening value and max jitter will be in section 4.2.4 HDMI Source TMDS Characteristics of the spec.

Thanks

David

Hi David

Thank you for your answer.
I checked a copy of the HDMI1.4b spec.
For confirming My recognition, Please let me ask an additional question.

About jitter of the output signal
Reading from the mask in "Figure 4-30 Eye Diagram Mask at TP1 for Source Requirements" in 4.2.4, is it sure that the maximum jitter value of the TMDS181 output signal is 0.3UI?
I recognize that the mask described in 4.2.4 is for the transmit component output.
If 0.3UI is the maximum jitter value of TMDS181 as described above, it is thought that the mask is violated when the signal is degraded by the board pattern and receptacle connector.
Is my understanding about that right?

About input mask
Is it correct that the input signal mask is also the same as the mask in Figure 4-30 described in 4.2.4?
For an input signal, I thought it is the mask described in the chapter "4.2.5 HDMI Sink TMDS Characteristics", but is it not?

Best regards,
Tamiya

Tamiya-san

If you look at Figure 4-29, the eye mask requirement is defined at TP1. The TP1 represents the connection point of the receptacle. So the mask is not the transmit component output.

For the input, it is the mask requirement at TP2 and shown in Figure 4-32, because this is eye the TMDS181 input needs to tolerate.

Thanks

David 

Hi David,

thank you for your checking.
I understood that TP1 is defined at the transmit receptacle and TP2 is defined at the receive receptacle.
I also understood that the values defined in TP1 and TP2 are not component specifications.

In that case, please tell me what is the value of maximum output jitter of TMDS181.

Best regards,
Tamiya