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SN65DP159: SN65DP159RGZ no HDMI data output,but I2C can normally read and write.Please help to solve the problem!!!Thx.

Part Number: SN65DP159

Hi,

SN65DP159 (I2C mode) have no picture output to screen with HDMI1.4b,but we can read I2C registers with ID address.
We also tried to switch to pin-strap mode to verify the correctness of the I2C configuration, but there was no output.

One strange place is that the level of I2C_EN we measured is 2.3V(already pull up to 3.3V with 64.9k resistor).

We need your help to solve the problem.
Looking forward to a quick reply.

  • Hi,

    Can I please take a look at your schematic? 

    Can you verify that you have a solid ground connection to the DP159 thermal pad?

    What source are you using? Is it a DP++ AC-coupled source?

    Thanks

    David

  • Thanks Reply.
    We are now using the xilinx k7 platform to control the output of a standard stripe image. The picture is the schematic diagram we are using now, and the thermal pad is  grounded firmly.

  • Hi,

    With the DP159 OE pin being actively driven, can you please make sure the DP159 power-up sequence is met?

    Can you please dump out both the DP159 page 0 and page 1 registers? The page 0 register is included in the DP159 datasheet. For page 1, please write to 0x01 to register 0xFF first, and then dump the register from 0x00 to 0xB1.

    Can you also measure the clock input and clock output of the DP159? 

    Thanks

    David

  • We use FPGA to control the timing of the OE pin to meet the power-on sequence requirements.

    The register export of DP159 page 0 and page 1 is added in the attachment.

    And we cannot measure the input and output clock of DP159 with an oscilloscope.

    Register0-1.rar

  • Hi

    Can you save the register dump in HEX instead the ASCII? 

    Are you seeing the HPD_SNK being driven high?

    Thanks

    David

  • Please can you explain it clearly at once if you have any questions?

    Because the time between our responses is too long. I can't stand it a bit.Thank you.

    It has been detected by the multimeter that the HPD_SNK pin has been pulled high(about 4.5V).

    Can't you automatically convert ASCII to HEX? It's not troublesome for you. You would rather spend twelve hours waiting for my reply. This really makes me doubt your work attitude.

  • Hi,

    I tried to convert ASCII to HEX. The register 0x00 to 0x07 is OK, but register 0x08 is read-only and the HEX value 0x01h does not match with the provided ASCII code.

    There is a register in Page 1 that can be used to approximate the input clock frequency, but the ASCII code '.' does not match the expected 300MHz input clock frequency for HDMI1.4. So is it possible to have the register dumped in HEX?

    Is J7 a standard HDMI connector or a customized connector? In the pin-strap mode, I would expect the DP159 to work at HDMI1.4 if the FPGA supports clock stretching. Can you put the DP159 into the DDC snoop mode?

    Is it possible to have a scope to measure the input clock and output clock frequency? 

    Thanks

    David