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Altera_Forum's avatar
Altera_Forum
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17 years ago

Phase Shift Reconfiguration

Hi,

I am wanting to configure a phase shift routine on the Stratix II FPGA.

Within Quartus I have used the altpll_reconfig and altpll megafunctions to generate the apporopiate block diagrams. I have also created two mif files to be used - one the initial settings and one containing the reconfig settings.

However, from here I do not know how to modify the reconfig mif file to generate the appropiate phase shift - 45deg on clock 0.

Any help would be great,

Thanks.

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    When you open the altpll with megawizard, you can change the phase in "output clocks" tab and generate mif in "PLL reconfiguration" tab. Put mif file name and push "Generate A Configuration File" button. After generating mif file, you cancel the altpll to save original setting.

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    --- Quote Start ---

    When you open the altpll with megawizard, you can change the phase in "output clocks" tab and generate mif in "PLL reconfiguration" tab. Put mif file name and push "Generate A Configuration File" button. After generating mif file, you cancel the altpll to save original setting.

    --- Quote End ---

    Hi,

    I have tried this. However when i generate mif files for different phase shift configurations (which i have changed via the ALT_PLL megafunction),there is no difference between the mif files.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    I have now managed to configue the phase shift - with the help of this example : http://www.altera.com.cn/literature/an/an367_3.zip

    However, my problem now is that each phase shift is off such a small magnitude. I have tried to change the extent of the shift, but cannot seem to. Does anyone know how to do this?

    Thanks for any help!