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Altera_Forum's avatar
Altera_Forum
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17 years ago

Dual Purpose Pins - nCSO

Sorry for the newbe question, but I know I'm supposed to be able to define the behavior of the nCSO after configuration, but when I go to Assignments -> Settings -> Device -> Device and Pins options and then the Dual Purpose Pins and the Configuration Tabs.

I have a DE2-70 board and it came with Quartus II 7.2 (I have not upgraded to 9 yet).

Anyway - although the litterature (and the tabs) say I should be able to change the behavior of the pin after programming - I can't see what I have to do on those two tabs. Can anyone help me on this?

The DE2-70 board has a switch iSW7 assigned and physically connected to that pin. I'd like to use logic vectors like iSW, but can't because there is a conflict on that pin (AD_25).

Thanks in advance,

Billy

12 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Billy, I have exactly the same problem.

    Please, people from Terasic or Altera, help us to solve this problem with the DE2-70.

    Tanks in advance.
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    No, SW7 isn't connected to nCS0 (PIN_K9). It's connected to nCE0 (PIN_AD25). This pin has to be selected as IO-Pin in pin configuration, of course.

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    OK - sorry I got the term wrong - but how do I select it to be I/O after programing as opposed to a programming pins. The two tabs I mentioned do not seem to allow me to do this.

    Thanks,

    Billy
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    As far as I remember, all you need is to use the pins and assign them to your top level ports then read/write to them as usual. The compiler takes care of the change over after configuration.

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Again, sorry for keeping posting and the possible wrong terminology.

    Anyway - the VHDL compilation works fine. No errors there. Later (in the script) when it goes to place (Fitter?) everything it has an error saying that the pin AD_25 is already assigned to nCEO and cannot be assigned to iSW7.

    Here are the messages:

    Info: Fitter is performing an Auto Fit compilation, which may decrease Fitter effort to reduce compilation time

    Warning: Feature LogicLock incremental compilation is not available with your current license

    Info: Fitter is using the Classic Timing Analyzer

    Info: Timing requirements not specified -- quality metrics such as performance and power consumption may be sacrificed to reduce compilation time.

    Info: The Fitter has identified 1 logical partitions of which 0 have a previous placement to use

    Info: Previous placement does not exist for 92 of 92 atoms in partition Top

    Info: Device migration not selected. If you intend to use device migration later, you may need to change the pin assignments as they may be incompatible with other devices

    Info: Fitter converted 3 user pins into dedicated programming pins

    Info: Pin ~ASDO~ is reserved at location G7

    Info: Pin ~nCSO~ is reserved at location K9

    Info: Pin ~LVDS195p/nCEO~ is reserved at location AD25

    Error: Can't place pins assigned to pin location Pin_AD25 (IOC_X95_Y2_N1)

    Info: Pin iSW[7] is assigned to pin location Pin_AD25 (IOC_X95_Y2_N1)

    Info: Pin ~LVDS195p/nCEO~ is assigned to pin location Pin_AD25 (IOC_X95_Y2_N1)

    Error: Can't fit design in device

    Billy
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    I assume you went to dual purpose pins setting and set the relevant pin as "io" after configuration. If this pin is greyed then it can't be dual

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    With DE2, you should have selected AS configuration scheme. Then nCEO can be set to "Use as regular I/O".

  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    Active Serial (on the Configuration tab) is the default and it does not allow me to change anything on the Dual Purpose Pins tab.

    Changing to Passive Serial Changes nothing

    Changing Auto to any of the other options does not allow me to change it either.

    Do I have to write a script??

    Billy
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    I change it by double-clicking on the value field. Of course you can enter a tcl command as well: 

    set_global_assignment -name CYCLONEII_RESERVE_NCEO_AFTER_CONFIGURATION "USE AS REGULAR IO"
  • Altera_Forum's avatar
    Altera_Forum
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    17 years ago

    I know it sounds stupid, but double click is the solution.

    You can't select it, no right mouse or left mouse will change it, clicking on the name or double clicking on the name won't work either.

    Only double clicking the value!

    Thanks again.

    Billy