Search FAQs on the left to see if your question has been answered. Click on the dropdown to view all of the documents associated with the product. If you can't find your question, click on Ask a Question. 

When I try to write to I2C registers of the ADI HDMI transmitter, the register values do not change.  What is going on?

  • When Hot-Plug Detect (HPD) is low the HDMI Tx will automatically go into power down mode.


  • After an HPD interrupt, register 0x41[6] must be set to ‘0’ to power up the part


  • During power down all registers except for 0x97 – 0xAF are reset to defaults


  • Most HDMI Tx devices (except AD9889, AD9389, AD9387, ADV7520, ADV7521) have an "HPD Override" function
    • These devices will operate same as if HPD = 1 when HPD "override" is enabled
      • On the ADV7510, the registers will reset on an HPD = 1 -> 0 transition

      • On the rest of these HDMI Tx devices the registers will not reset on an HPD = 1 -> 0 transition
    • HPD state and interrupt registers remain avaiable even of HPD Override is enabled

Comments
Anonymous
Related