DS90UB941AS-Q1: Please provide the init register config for splitter mode

Hello Chen,

It is not possible to meet both of these panel specifications in splitter mode since the 941AS splitter mode changes unused lines from the vertical cropping into blanking. There is no way to remove blanking lines when cropping the 3D superframe image so in this case since one of the panels has 720 lines, but the second panel has only 480, then 720 - 480 = 240 lines of vertical blanking will be added to the smaller image after cropping in addition to the original blanking from the superframe itself. That will go well above the 480p panel's allowable blanking based on the spec provide above. 

You could drive these two panels with 941AS though if you use 2x independent DSI sources, and operate the 941AS in independent 2x2 mode. 

Best Regards,

Casey 

Hello Chen,

The allowable blanking would be based on the panel side which is not something we can comment on from the TI standpoint. You would need to confer with your panel supplier for information on the allowable panel tolerance. The vertical blanking of the 941AS output in splitter mode is equal to the vertical blanking of the original superframe image (the one which contains two images to be cropped), plus the number of cropped out active vertical lines from the superframe. In this case it would be 720-480 = 240 lines plus the original superframe blanking for the smaller image. 

Best Regards,

Casey 

Hello Chen,

This is not related directly to HSYNC/VSYNC, and yes the situation is exactly the same for splitting with VCIDs as well. 

Best Regards,

Casey 

Hello Amelie,

This statement is incorrect - the 941AS can support asymmetric splitting as described in the datasheet, but it does come with considerations which need to be made on the blanking and video parameters of the resultant videos. The main point is what we discussed earlier in this thread - cropped out video lines are converted from active video to blanking when doing this kind of split. So whether or not a specific system configuration can work depends on the difference in vertical resolution between the two panels and the tolerance of the panels. 

You will find that in the market there are many types of display panels with varying tolerance on blanking parameters and PCLK. Some can tolerate much more blanking than others, while some have a very narrow window of allowable operation. So in this particular case, the panel tolerances wouldn't allow this type of split, but there are other system configurations or panel configurations which can work with this scheme. 

In general 941AS is most suitable for asymmetric splitting cases where the two panels have similar vertical resolution. If there is a large difference between the vertical size of the two panels, then doing a split like this will introduce a more difficult requirement for the smaller panel. An example of a split that would be ideal for 941AS would be 1920x720 and 1280x720, as both the panels have different resolution but the same vertical dimension. 

Best Regards,

Casey 

Hello Arvin,

If you are implementing the split we discussed between a screen with 720 lines and a screen with 480 lines, then I assure you that the blanking for the smaller screen will be at least 240 lines due to the splitting implementation. So in this case, I would recommend to consult with your panel vendor to confirm on the spec of the LCD. The most likely scenario is that the panel was only validated for the blanking which is described in the spec that you shared and not outside that spec, or the panel can work outside of that spec, but not under all operating conditions such as process, voltage, temperature. 

But from the 941AS side hopefully it is clear now how the device behaves. 

Best Regards,

Casey