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Altera_Forum's avatar
Altera_Forum
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7 years ago

PLL of Cyclone V: 'reconfig_to_pll' bus description needed

Hi community,

I'm working on a Project that has to be migrated from a Cyclone III to a Cyclone V FPGA.

My problem is the PLL reconfiguration. Normally, the reconfiguration is processed by use of the PLL reconfiguration megafunction.

In my application, I can't use this tool. For the Cyclone III, we've created a own simple design to handle the scan chain. This was possible, because the scan chain is well documented.

Unfortunately, the PLL reconfiguration on the Cyclone V is completly different (it uses a 64Bit reconfiguration bus), and my problem is, that I could not find any description of the bus signals nor the bus timing.

My question is: Can anybody give me a hint, where to find this information? Or has anybody a description of the bus?

Thanks :)

Find attached a screenshot that illustrates my question

1 Reply

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

    Altera/Intel don't publish the details of that bus.

    Can I ask why you don't want to use the PLL_RECONFIGURE IP - as is intended for PLL reconfiguration? You're clearly intending to do some redesign work in moving to Cyclone V from Cyclone III. Why not incorporate the PLL_RECONFIGURE IP and use the two bits of IP as intended? Controlling the PLL_RECONFIGURE IP is pretty straightforward...

    Cheers,

    Alex