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Honored Contributor I

Cyclone III Nios II LCD problem



The newbie is having problems once again... :rolleyes: The first experiment I did with the VIP suite worked perfectly (test pattern generator), but everytime when I start from scratch, the test pattern failes to show properly... (I'm trying to get it working again for a few days now...). A strange thing I noticed is that the fitter places the design in a complete different section of the FPGA compared to the working example. Could this cause the problem? 


I'm having some "flashes" running over the screen every 30 seconds, and the white line is grey instead of white and it's bottom corner is black (like the picture). The timing requirements are perfectly met (as says TQ). The design builds perfectly, the "only" warning I have is: (I have this warning also in the working design...) 


Warning: PLL "pll:inst|altpll:altpll_component|pll_altpll:auto_ generated|pll1" output port clk[0] feeds output pin "V_clk~output" via non-dedicated routing -- jitter performance depends on switching rate of other design elements. Use PLL dedicated clock outputs to ensure jitter performance 


The complete design is included in the attachment. I really hope someone can give me some hints where to look for the problem (timing, fitter, settings,...) or confirm they have the same problem with the included .sof file as I have. 


For some more general information I'll describe what I want to create with my neek dev board (as I am more of a programmer and the whole FPGA concept is still quite new for me): 


A SOPC system containing: 


-Nios II processor (with Sram and flash) 

-DDR memory 

-touch panel interface 

-2 24-bit BGR- frame buffers (VIP suite) 

-2 8-bit alpha-frame buffers (VIP) 

-Alpha blender (VIP) 

-Clocked video out to LCD (VIP) 


With this hardware setup I can start some fun programming experiments, 


Thanks for your help! 




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Honored Contributor I

Hi Hans, 


EDIT: misunterstood the post. :D So here is the new version: 


The Clocked Video Out has a wrong resolution, so I only had a black screen. When changing that into 800x480 it runs perfectly on my board, means no flashes and no black corner. 


Also the sync pulswidths is 5, I thougth it should be 1, but I don´t know if that matters in any way. 

I also have the warning. 




Honored Contributor I



How stupid could I be... You are completely right. 

You're a real life saver:D  


Works perfectly now! 


Sorry for the trouble. 


Best regards