Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
21 years ago

UART stops working after changing core

I have changed a NiosII project from tiny core to small core, and bumped up the debug up to level 3 to take advantage of hw debug. This change has broken both the jtag uart and the standard uart, which either produce no output or some garbled characters. App is simple hello_world loop. I am almost certain I had this exact config all working before. I have tried all the standard fixes of rebuilding, recreating launchers, rebooting. Short of going back to tiny core, nothing works. Where is that short list of uart voodoo again?

2 Replies

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

    I switched from s core to f core or e core and the uart works. I switch back to s core and it is consistently broken.

    There is no room for level 3 debug and the f core in my device, but I believe there would be with the s core.

    Are there known errata specifically with the s core? I really want to try out the trace feature.

    QII4.1, NiosII1.01
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    20 years ago

    Clarification: the uart is not the primary problem. The download is either failing at some point, or the downloaded code is no good. When using the \s core, I can't debug or even toggle a pin. I moved my project to Q4.2/NiosII1.1 and I get the exact same results, \e and \f core are fine but not \s. Thinking there must be a problem with the project itself, I compared ptf files.

    For both e and f core there are a couple of lines that read:

    JTAG_Hub_Instance_Id = "0";

    But for the s core this value is "1". This value appears to be assigned during Generation. I thought the difference suspicious, so I

    manually changed it to "0" before compilation, but all I got was a project that could not be downloaded, "There are no Nios II CPUs with debug modules available....".

    There must be something wrong in one of my project files. Any ideas short of rebuilding the project?