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DLPC230-Q1: Possible to use 16bpp OpenLDI

Part Number: DLPC230-Q1

We are attempting to use a SOM with 2 LVDS video outputs to control 2 independent DLPC230-Q1.  One LVDS output works perfectly with RGB888, but the second LVDS output only has 3 data lanes so only supports 16 bit mode.

I don't see anywhere that specifies any supported mode on the DLPC230 other than 24-bit RGB888.  Is there any lower level command that could be used to change the video format to RGB666?  Even better would be a single color 16bit grayscale.

  • Hello,

    Please note a member of my team will be responding to your question shortly.

    Thank you,

    Aaron

  • Hi Wayne,

    Using the OLDI interface, unfortunately, there does not appear to be a way to map the 666 data into the device on 3 lanes.  It is hardcoded with the following mapping shown below (from the datasheet). 

    Jason

  • That looks like it is from the DLPC230S, I'm not sure if that makes a difference.  The DLPC230 does have a similar diagram, but this one is easier to follow:

    I have a partial solution of swapping the DATA1 and DATA3 lines in the DLPC230 configuration.  That gets rid of the stuck R7 and R6 bits by moving them into G2 and G1 which are ignored (from what I understand, the DLPC230 only listens to Red bits, at least in headlight mode).

    The only downside to that solution is it means I am effectively limited to the lower 6 bits, so the effective brightness is 25%.

    I agree that the datasheet does not list any way to map the data any differently.  I was hoping there was another way based on what you see in the Batch Command Sets in DLP Composer, it almost looks like there could be another mode (maybe just because the software works with more chips).  I tried to see if I could export that command set and re-import it as a custom one, but it just shows "Internal Command" for every line.

  • Wayne,

    The DLPC230 and DLPC230S have identical silicon.  The S version provides documentation to achieve functional safety metrics necessary for some applications.  Unfortunately, the HW allows for physically swapping the ports, that is meant to ease PCB layout, but there is not a way to actually map the bits differently, which is what you need.  I double check the internal HW spec and it does seem to be hardcoded.

    In looking at the bit mapping, I also do not see a good way to map in the bits that you need.  You need to map the the 6 bits into the 7:2 of each color to get the right results, otherwise the brightness would reduce.  Actually what is happening is the MSB and MSB-1 are zero, thus this information is missing, not just brightness.

    I do not have any good ideas.  I think the only way to get it to work would be to route all 4 channels across.

    Jason