Can't use 27MHz clock with Altera DE2 Board

[Matze]

Hi, I'm currently working with the Altera DE2 board. To get started with it and the Quartus Software I've implemented a simple circuit using an open source IP-Core (PacoBlaze). The board provides two clock inputs, a 27MHz one and a 50 MHz one. For the first time implementing the design (timing constraints: 50MHz) I used the 50MHz clock and it worked perfectly. Then I tried to use the 27MHz clock and the design didnt work at all. The pushbuttons I used as an entry didnt have any effects on the outputs.

So now I'm wondering why it works with one clock but not with the other. I couldnt find that there is anything special with the 27MHz clock in the manual. Has anybody an idea what the reason for this could be?

Thanks in advance!

 

[dk614nd]

Re: Altera DE2 Board

did u change the pin assignment, check the pin mapping report

 

[mess123]

Re: Altera DE2 Board

Hi Matze,... i am a beginner in verilog/fpga programming. I wish to know how did you configured in the program which oscillator to use in the altera De2 board.