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Altera_Forum
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17 years ago

Help: IO Pin as clock?

Is it possible to use a ProtoIO pin as a clock driver? The reason I ask is I would like to interface a 40 pin daughter card with an HSMC port using an HSMC to 40 pin debug header but the clocks don't line up. If it is possible, how would I go about assigning this in Quartus?

Thanks.

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  • Altera_Forum's avatar
    Altera_Forum
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    --- Quote Start ---

    Is it possible to use a ProtoIO pin as a clock driver? The reason I ask is I would like to interface a 40 pin daughter card with an HSMC port using an HSMC to 40 pin debug header but the clocks don't line up. If it is possible, how would I go about assigning this in Quartus?

    Thanks.

    --- Quote End ---

    Hi,

    there is no basic problem to use an FPGA I/O as a ock driver. You have to assign your clock signal to an I/O, which is connected to the HSMC port. You can do that with the Assignment Editor or with the Pin Planer tool in Quartus.
  • Altera_Forum's avatar
    Altera_Forum
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    Yes, you can use the I/O pin as a clock driver. Take care about using a low output drive strength (I suggest you 4mA) in order to avoid annoying overshoots that may intefere with the adjacent data lines.