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DS90UB948-Q1: Using DE-Only displays with the Pattern Generator

Part Number: DS90UB948-Q1

A little background: Our product has two '941AS serializers, which will connect to two different purchased display units, each with a '948 deserializer. While the software guys are working on DSI drivers, I bought a DS90UB949-EVM so I can sort out the display units. With one 1920x720 display, I've got it working well enough, with Analog LaunchPAD letting me control and script GPIO, see all the registers, and control the Pattern Generator. I have a Raspberry Pi as an HDMI source.

The issue: So, today I finally got a hold of the other 1280x720 display that's going to be used. All seems equally well with the '949 talking to the '948. Everything says that everything is fine, except I can't get an actual image. According to my scope, the LVDS clock and data pairs on the display unit look as I expect. BUT, I found out that this display is "DE-Only", so I presume this signal is usually generated at the video source. My question (finally) is if or how the pattern generator can generate this DE signal? There are settings for H and V sync and polarity, but nothing about generating DE. Is this doable? Are there any notes about using "DE-Only" displays?

  • Hi Lary,


    Our serializers do not have the ability to generate DE-Only test patterns. When using our serializer and deserializers with a DE-Only display and DE-Only video input, the HS/VS signals are ignored and just need to be set so that the values sum up to the correct hblank/vblank.


    Please let me know if you have any additional questions.