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Altera_Forum's avatar
Altera_Forum
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9 years ago

VGA Controller to Cyclone II

Hello,

I am new using FPGA and I appreciate if anybody can help me with VGA.

I used the code in this link (https://eewiki.net/pages/viewpage.action?pageid=15925278) in a Cyclone IV and it works perfectly. However, when I try to change the device to a Cyclone II board (EP2C35F672C6) it shows a PLL error. Can anybody help me with that? Or show me a code project that at least show a little square at the screen?

Thanks in advance.

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    9 years ago

    The PLL used in Cyclone IV is different to that used in Cyclone II - even though they are both, apparently, the same 'ALTPLL' primitive. Cyclone IV's PLL has more features, output clocks and options. It's possible that the PLL is using more features than are available to you in Cyclone II. However, whether it is or not, Quartus is likely to simply reject the design as it refers to a PLL it can't use in Cyclone II.

    Assuming the design you're looking at doesn't use any of the Cyclone IV specific features, or too many output clocks, you can revisit each PLL in the design and regenerate it for Cyclone II.

    Cheers,

    Alex
  • Altera_Forum's avatar
    Altera_Forum
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    9 years ago

    --- Quote Start ---

    However, whether it is or not, Quartus is likely to simply reject the design as it refers to a PLL it can't use in Cyclone II.

    Assuming the design you're looking at doesn't use any of the Cyclone IV specific features, or too many output clocks, you can revisit each PLL in the design and regenerate it for Cyclone II.

    --- Quote End ---

    I Tried to compile in a Cyclone V board and it shows another PLL error...

    Is there a way to change it automatically using a block?

    Do you know a simple code to VGA that works in Cyclone II?

    Thanks!
  • Altera_Forum's avatar
    Altera_Forum
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    9 years ago

    Unfortunately, the PLL changed again in moving to Cyclone V. So, you're hitting, essentially, the same problem. Again, you need to re-instantiate the PLLs for the particular device family you're targeting.

    Are you using a standard development board for this? Terasic do a altera cyclone ii de1 board (http://www.terasic.com.tw/cgi-bin/page/archive.pl?language=english&categoryno=53&no=83) which features a VGA DAC and connector. They offer plenty of design examples - see the 'Resources' tab. I'm sure you can find a suitable VGA example in there. Download the 'CD-ROM'. If you haven't already you'll have to register to allow you to download it.

    Cheers,

    Alex