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Altera_Forum's avatar
Altera_Forum
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16 years ago

Writing to (and reading from) serial configuration device after config is done

Hi there,

As part of a remote update scheme I want to be able to read/write to the unused area of the EPCS64 configuration device, as suggested in chapter 12 of the Arria GX handbook.

My problem is that the handbook is a bit vague about how this is done. I assumed that the 4 pins that connect the Arria GX to EPCS64 could be reserved as 'regular I/O' after config complete and then used to crank the serial data in/out using custom FPGA code. But Quartus does not allow me to re-use the pins in this way ('regular I/O' isn't a valid choice in the Settings/Device/Device and pin Options dialogue).

So how should I get my user code to connect to the EPCS64 serial device? Answers needed urgently and will be much appreciated!

I'm using Arria GX and the AS configuration scheme, by the way.

Thanks,

Greg

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Hi Greg,

    You can do it using the EPCS Serial Flash Controller in SOPC Builder. If you're using a NIOS processor then that would be the way to do it.

    Cheers
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Thanks sharkybaba.

    I'm not using a NIOS processor in my design ... but I think I have an answer to my own question. It appears that in my situation I cannot directly access the connections to EPCS64; instead I must use the altasmi_parallel megafunction (which I previously knew nothing about!)

    Cheers,

    Greg
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Greg,

    I suspected there might be a megafunction for it but the only one I could find didn't look quite right.

    Good luck with it.

    Sharkybaba