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  1. #1
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    How to plot the contains of RAM on VGA screen?

    I am very new in vhdl.

    I have Spartan 3 development board with 25 mz crystal.

    I want to generate RAM inside the Spartan and want to plot the contain of ram on VGA screen. With resolution of 640X480. My testing VGA code is working fine.

    if possible please give me solution how I can plot line circle. is possible.

    Please help me

    Thanks in advance

    Nimish

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  2. #2
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    Re: vhdl vga

    Hey Nimarc,

    the vhdl code for VGA is just the interface. You need to use a Microcontroler to control the text, some draws, etc. The Spartan chip just convert the bus signals in vga digital signals. You can connect a keybord or a mouse to your microcontroler, and make some program, some structs, some classes to acquire your signals from mouse and/or keyboard and send the output to Spartan chip to you can see in vga screen. Its a nice way to spend some boring time in usefull things!!!! good luck

    Breno



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  3. #3
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    Re: vhdl vga

    generaly it's good practice to buffer whatever you want to draw in RAM, blockRAM's are perfect for this (because you don't need to use double buffering) but storing there data for VGA is very memory consuming, so if you don't need blockRAMs for anything else than ok, otherwise if you have any SRAM on board you can use that memory instead (but I suggest using double buffering then), now you just create some process for vga interface to read the RAM and draw contents on the screen, if you do this than you have fully working vga controller and you can simply forget about it and start thinking about data to draw, personally I don't have any written code in HDL to draw lines but you should check out Bresenham's line algorithm for drawing line, I think that circles will be more tricky and I would cope with them later if I were you :)



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