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

Problem when changing FMAX of system

Hi,all!

I try to increase the working frequency of NIOSII processor on 1s40 board.

Following is what I do:

1. copy the example design "standard" from the install directory "altera/kits/nios2/example".

2. change the c0 out put of PLL to a higher frequency, for example, 60MHz.

3. change the system frequency in sopc builder to 60MHz, too.

4. save&compile

I have done the same thing months ago, and got no problem. But this time the system just don't work. After compilation and download the sof file to my board, I try to run some simple program like "hello world", but it doesn't work. Why did that happen? Thank you for any suggestions!

2 Replies

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

    If you are using Nios II/Quartus II 5.1 be sure to upgrade to at least Quartus II 5.1 SP1.

    When you say it doesn't work what warnings/errors are you seeing?
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    19 years ago

    Have you also increased the SDRAM clock? Or maybe the SDRAM timing isn't correct and you need to recalculate the phase shift.