SN65DP141: A flower screen appeared using SN65DP141

Hi,

Are you AC coupling the AUX signal and having 100k pullup to 3.3V on AUXN and 100k pulldown on AUXP? 

Are you also configuring DP141 through its registers? 

I assume both the DP141 input and the output are AC coupled? The flower picture should come from the DP source, the DP141 will not generate any pattern since it is a re-driver only.

Thanks

David 

hi David，

Ac coupled AUX signals, 100k pull-up to 3.3V on AUXN, 100k pull-down on AUXP, are available.

The software is configured with DP141 through its registers. The four registers configured are as follows, and the configured values are as follows；

registers     data

 0x02         0x03
 0x05         0x06
 0x08         0x06
 0x0B         0x06

Hi,

Is there a reason you are programming lane 0 with a different value than the other three lanes? 

I assume this is a source side design, how long is the trace from the DP source to DP141? Have you done the DP compliance testing? 

Refer to the table below, it looks like you are doing cable mode, is this correct?

Thanks

David

hi David，

Update the configuration of the register

Hi,

Can you share your layout? How long is the trace length from the DP source to the DP141? 

Have you done the DP compliance test yet?

Can you also share a picture of your flower screen?

Thanks

David

hi  

5860mil from DP source to DP141; configuration：cable mode ，

Hi,

Does the 5860mil include the cable or just the trace length? What data rate are you running, 2.7G, 5.4G, or 8.1G?

I would disable DRV_PEAK for now, so register 0x03, 0x06, 0x09, 0x0C would be set to 0x00, and I would change the EQ setting (bit 6-4) of register 0x02, 0x05, 0x08, and 0x0B to see if it improves the flicking screen would improve, you can start with a value of 0x38.

Thanks

David

hi expert,

I changed the value of the register, but there is no improvement, do you have a better way for this?

Hi,

Can you please accept my friendship request so you can send me the schematic and layout (Allegro format) in a private message? 

Have you tried to change to a shorter cable and see it helps?

If you go with a lower video resolution, does it help as well?

Thanks

David