HDMI Debugging - 1.0 English

HDMI GT Controller LogiCORE IP Product Guide (PG334)

Document ID
PG334
Release Date
2023-10-18
Version
1.0 English
  • What to check if I do not see TX or RX Frequency Events?
    1. Make sure the HDMI cable is properly inserted.
    2. Ensure that the correct GTREFCLK input pins are connected according to Customizing and Generating the Core.
    3. Ensure that the cable detect and HPD pins are properly connected with the correct active level setting in the HDMI TX or RX subsystem GUI.
    4. Try connecting with a different cable.
  • Why does the HDMI GT Controller log shows an error saying no DRU instance?
    1. This indicates that the HDMI design received a video carrying a TMDS Clock that is below the PLL thresholds and there is no NI-DRU in the IP instance to receive it.
    2. The DRU must be enabled from the IP GUI to be able to receive resolutions below the PLL threshold. The DRU must be supplemented with a corresponding GT clock based on the requirements listed in Reference Clocks Requirements.
    3. Ensure the GTREFCLK is present and is driving the PLL.
    4. Try toggling the PLL_GT_RESET bits of TXI or RXI registers.
    5. Ensure that the HDMI GT Controller driver and IP versions are from the same Vivado build.
  • Why do I see a DRU reference clock frequency equal to 1 Hz?
    This happens when the clock detector module identifies a mismatch between the actual and required DRU REFCLK frequency. This can be due to two reasons:
    • The DRU clock frequency is outside ±10 kHz tolerance of the required frequency.
    • When the DRU Ref Clock Selection is the same as the RX or TX Ref Clock Selection, disabling the RX or TX Ref Clock Selection can also disable the DRU Ref Clock, which reports the DRU clock frequency as equal to 1 Hz.