DS90UB949A-Q1: HPD DDC toggling

Hi Sergey,

I will look further into your question and reply tomorrow. Thank you for your patience.

Regards,

Michael W.

Hi Sergey,

What do you mean toggle HPD, The HPD should be high when the HDMI ready to receive signals from the source. Do you need HPD to toggle after this?

Regards,

Michael W.

After powerup SRAM EDID is loaded with values  from fuse, then I load new EDID to SRAM, to apply it I need to toggle HPD.

What are your MODE_SEL0 ,and MODE_SEL1 set to?

In my scenario I don't want to implement remote EDID on DESER side and external local EDID EEPROM on SER side.

Instead would like to load EDID from DESER side to SRAM on SER side and apply it.

1.Initially I used MODE_SEL0 #1 (EDID_SEL=0) and MODE_SEL1 #2 (REM_EDID_LOAD=1, EXT_CTL=0) . 

This layout worked like this: no answer on remote EDID and EDID was taken form SRAM where Fuse'EDID was loaded during powerup. 

I loaded EDID to SRAM from DESER side and then I had no possibility to influence to HPD to apply new EDID.

Even if I could it's not a solution due to the fact that initially TI EDID applied, then my own.

2.Now I changed to  MODE_SEL0 #3 (EDID_SEL=1) for the purpose of not applying to SRAM and MODE_SEL1 #5 (REM_EDID_LOAD=0, EXT_CTL=1) for the purpose of not to load HDMI receiver configuration until I load new EDID to SRAM.

Then I program SER registers to  EDID_SEL=1 and EXT_CTL=0 to load HDMI receiver configuration and using of SRAM with new EDID.

As I mentioned this way works but I'd like to influence to HPD not only by EXT_CTL=1 but somehow through HDMI registers.

Hi Sergey,

Why did "1" not work for you?  did you try monitoring the remote I2C to see if the I2C transactions were getting to the DES?

Regards,

Michael W.

#1 works, I2C transaction for 0xA0 DDC address initiated, but it's not in my scenario due to the fact I don't want to spend resources on DESER side to implement I2C slave for EDID. Instead I'd like to use existing I2C master on DESER side for EDID loading to SER SRAM.

So, is it possible to get control to HPD through HDMI registers which are mentioned in data sheet but not described?