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Altera_Forum's avatar
Altera_Forum
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16 years ago

Combining AS and PS configuration schemes

Hi,

I'm designing a custom board with one Arriagx and 3 cyclone III.

I would like to connect an EPCS with each Cyclone and configure the cyclone with the Arria.

It means that I have to used the AS configuration(EPCS) and the multiple PS configuration(Arria) together.

Can I combine easily the two configurations or should I differentiate the two configurations with jumpers?

Has somebody already worked like that?

thank you much,

ben

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Your plan involves changing the MSEL pin strapping, that is sampled on FPGA power-on reset. Altera suggests not to use logic to drive these pins, so jumper or switches would be a save solution.

  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Hi FvM,

    you're right , my plan was to change the MSEL by soft but also the DCLK and DATA0 pins.

    In the evaluation board from altera , the max command the MSEL pin in order to choose the configuration scheme. They have a AS configuration or a PS configuration.

    I would like to do the same. The difference with a evaluation board is that I don't have any MAX but an arria and I have 3 cyclone.

    But in your opinion it's not a save solution.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    In my opinion, it can be save. I think, Altera wanted to issue a warning, that an undefined MSEL state during power up can cause inpredictable device behaviour. If you drive MSEL by an Arria, that is typically releasing the power-up reset at the same time as the slave Cyclone FPGAs, you should think about a means as strong pull-up/pull-down resistors or additional drivers to ensure stable MSEL conditions. In any case, you should try yourself, what must be done.