i.MX6DL HDMI TX wave form.

[takashitakahash]

Hi community.

Our customer has below question.Woukd yuo please advice.

HDMI Source testing results, anomalies were observed in the TMDS line.

The product internal circuit configuration, through a common mode filter iMX output, only have output connector, we do not find a factor that becomes the corresponding waveform.

See Attached.

Would you please advice factor as IMX inner workings and configuration registers corresponding event occurs check.

Thanks,

Best.

[art]

Please follow exactly the recommendations and procedures, described in the "i.MX 6 Series HDMI Test Method for Eye Pattern and Electrical Characteristics" AN4671 Application Note document, available on the NXP web site (check the "Application Notes" section):

http://www.nxp.com/products/microcontrollers-and-processors/arm-processors/i.mx-applications-process...

Have a great day,
Artur

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[takashitakahash]

Please tell me was measured in any setting)

Dear Artur-san.

Thank you for your previous replay.

Customer  investigated that had you replay references, and  found that the Pre-emphasis driver is one of the factors. ( Trailer A driver only was enabled).

Customer tried to OFF on trial, improvement in the waveform .Please see attachment fig .

However, it looks as if they are not still completely OFF.

Emphasis in the fall before the waveform is taking.

For CK has confirmed that there is no Pre-emphasis driver but, Data Similarly, there is a step in the waveform.

(It looks like Pre-emphasis is at stake)

Is this would be the correct behavior.

Would you please advice me there a way to resolve..

There is no difference in level in the waveform that is in the document.

Please tell me was measured in any setting.

[takashitakahash]

Dear Artur-san.

Regards so question again of HDMI TX signal assue .

Would you please answer as soon as possible.

Thanks,

Best.

T.Takahashi

[art]

The Section 3.8 of the i.MX6 series Hardware Development Guide Rev.1 document says the following.

Use the following recommendations for the HDMI.

• HDMI differential pairs should have a impedance of 100 Ohm in all paths to the connector.

• It is highly recommended to use an HDMI transmitter port protection for ESD, level shifting,

isolation, overcurrent and backdrive protecion.

The most likely cause of any possible issue is the violation of the recommendations above. Please follow the design of the i.MX6 SABRE SD board as the reference.

The document, mentioned above, can be found on the processor's Documentation page:

http://www.nxp.com/products/microcontrollers-and-processors/arm-processors/i.mx-applications-process...

Best Regards,

Artur