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ADV7619 HDMI Compliance Test Failure

Question asked by chrismhyao on Mar 2, 2016
Latest reply on May 13, 2016 by chrismhyao

Hi all,

 

We are experiencing HDMI 1.4b compliance test failure using ADV7619 + ADV8005 in our design as a HDMI sink device.

The test lab reported two items that we are failing:

- 8-6 TMDS Intra-Pair Skew: tested with pixel clock of 297MHz

- 8-7 TMDS jitter tolerance: it is failing on 297MHz pixel clock (passed 27MHz, 74.25MHz, and 148.5MHz).

 

Details are as follows:

********************************************************************

8-6 TMDS Intra-Pair Skew

Video Format: 4Kx2K @ 30Hz_24bit

Pixel clock: 297 MHz

D0+: 0.6 TBIT , D0-: 0.2 TBIT

D1+: 0.0 TBIT , D1-: 0.0 TBIT

D2+: 0.2 TBIT , D2-: 0.5 TBIT

CK+: 0.2 TBIT , CK-: 0.4 TBIT

********************************************************************

8-7 TMDS Jitter Tolerance

Case 1 (D_Jitter, C_Jitter) = (0.5MHz, 10MHz)

Pixel clock: 297 MHz

Cable Emulator: Type1 Cat2 Result: Fail

Cable Emulator: Type3 Result: Fail

Case 2 (D_Jitter, C_Jitter) = (1.0MHz, 7.0MHz)

Pixel clock: 297 MHz

Cable Emulator: Type1 Cat2 Result: Fail

Cable Emulator: Type3 Result: Fail

********************************************************************


For the Intra-pair skew issue, the first thing came to my mind is the layout, but I didn't find any issue with the PCB design; All the clock and data lines are matched in length to 0.5mm, the differential traces width and clearance are 100OHM impedance controlled, and the total length between the HDMI input to the ADV7619 Receiver is only about 35mm long. Judging from D1 lines's failure, even at 0.1TBit skew can cause the failure, it makes me to think this might be caused by the test setup or software setting.


So the next thing I am wondering is the equalizer and other register settings on the ADV7619.

We are currently using the latest software from Analog Devices on our device;

********************************************************************

  ADI VSP AVR Application Ver V1.90.2

  PLATFORM: EVAL-ADV8005-SMZ

  HDMI-RX:  ADV7619 Rev 0x20c1

  HDMI-TX:  ADV8005 Rev 0x6083 without Rovi

  Created:  Jul 14 2015 At 10:16:08

********************************************************************

 

Any suggestion to help me to solve these two issues?

 

As I was browsing through other threads relating to this topic, it looks like many of the Jitter Tolerance issues were resolved by changing the equalizer settings for different pixel clock rate.

I scheduled the lab visit next week, so I would like to have different set of settings on ADV7619 to try when I am there.

Any recommendation will be appreciated.

 

Thanks,

Chris

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