Forum: µC & Digital Electronics performance using big screens (tft)

von saoirse (Guest)

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I`ve a few questions about using a tft (480x272 or higher) together with 
the AT91SAM9263 controller. On the EBI1 bus, there`s a small PSRAM 
installed (needs 8 wait states). Moreover I`ve a continuous stream of 
incoming ethernet pkts (round about 15MBit/s) - these pkts needs to be 
processed in a fast way.

At the moment, if the user made some changes (touch, encoder)so that the 
tft needs to be updated, I wrote anything direct to the PSRAM. If one 
step includes a lot of pictures (10 images with 230x60 pixel), the 
ethernet stream is discontinued for one second. I also tried to use the 
sdram (which is faster than the PSRAM) to update the tft - but I still 
get the same behaviour: all the pictures located in the sdram;

What would be the best way to update the tft screen (if the user made 
some changes, touch, encoder and so on)? Is the usage of the dma 
recommended (because of the disadvantages using the link list (update 
after every block three registers)...)?

Are there any other recommendations / hints to update big screens 
(800x600 pixel)? How is it possible to change the whole screen - without 
any kind of notice in the ethernet stream?

best regards


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