We replaced on our board the revision 1.3 to 2.1 revision of the chip.
I changed the davincifb.c driver to disable the global field inversion bit in the OSD_MODE register.
We are using VIDWIN1. We fill the video buffers with a synthetic pattern.
The synthetic data is the same for all frames; we see flickering on the screen.
I connected, through JTAG, an emulator and stopped the processors (ARM and DSP). The flickering continues.
When we change back to silicon revision 1.3, the flickering disappears.
What might be the problem?
It seems like the problem is in the new silicon revision 2.1
There are some constraints outlined in section 4.3.1 of the VPBE User's Guide that when violated will result in a flickering effect.
Thank you for your quick response. We are following the rules of VPBE 4.3.1 and in silicon revision 1.3 it works fine. The problems started when we switched to new silicon revision of 2.1.
Are you using our DM6446 EVM or your own custom EVM? Can you tell me the conditions you are testing video output under? For example, resolution, refresh rate, pixel format... I want to see if we can reproduce this internally with silicon 2.1 on our EVM
We're using our custom EVM hardware with both silicon revisions. We don’t have the DM6446 EVM with new silicon, only with the old one. We are connecting the analog video output directly to display, resolution is 720x576, refresh rate is PAL standard and pixel format is YCbCr 16bit (all of this was copied from DM6446 EVM).
Great; I will see if I can get 2.1 silicon on my hands; this may take a couple of days.
Thank you very much. We appreciate your help and wait to hear from you.
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