2009-01-15 10:12:50 Suggestions wanted for LCD and touchscreen controllers
Steve Strobel (UNITED STATES)
Message: 67988
We are considering adding a LCD with touchscreen to a design using a BF537. A web search to see what LCD and touchscreen controllers others were using led to some quarter-VGA designs. We were thinking full VGA or even 800x600 might be an option. Can anyone recommend an LCD controller for those higher resolutions? Should we expect good performance, or is pushing that many pixels too much to ask?
Thanks for any suggestions,
Steve
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2009-01-15 10:44:23 Re: Suggestions wanted for LCD and touchscreen controllers
Jiri Beranek (CZECH REPUBLIC)
Message: 67991
I am using OSD057 640x480 connected to PPI, performance is not quite
goog. PPI DMA cause slower system - dhrystone test with PPI DMA is
121506 and without PPI DMA is aroud 300000. Some optimalization in
uClinux dist. is needed too to avoid PPI underflow.
J. Beranek
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2009-01-21 14:31:21 Re: Suggestions wanted for LCD and touchscreen controllers
Steve Strobel (UNITED STATES)
Message: 68202
> I am using OSD057 640x480 connected to PPI, performance is not quite
> goog. PPI DMA cause slower system - dhrystone test with PPI DMA is
> 121506 and without PPI DMA is aroud 300000. Some optimalization in
> uClinux dist. is needed too to avoid PPI underflow.
> J. Beranek
Thanks for the info. I presume that using an external display driver chip (like one of the Epson/Smos chips) that has its own framebuffer memory would remove that constant overhead. We used such a chip on a Coldfire design without an OS and found that updating it was relatively slow; it would often extend the bus cycles when writing to the framebuffer memory because the internal refresh logic was accessing the framebuffer memory. Does anyone have experience using such a controller chip on a Blackfin? Are there any other options?
Steve
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