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If the LCD controller has a lower priority on the EMC bus, refreshes will be stalled. How noticable is this on the screen?

Question asked by LPCware Support on Mar 30, 2016
Latest reply on Apr 26, 2016 by LPCware Support

If it happens, a DMA underflow will occur causing a tear. For the frame being rendered when this happens, the data under the spot of the display where the tear happen will be misaligned. Because the frame is being updated at a high rate (60Hz?), you see a quick flicker on the display. If the tear happens a lot, the flicker can be annoying.

It should be noted that the LCD controller will underflow only when it's DMA request is stalled for a considerable amount of time. The LCD controller has it's own buffer memory filled up by DMA and can handle short stalls during it's DMA request.

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