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DE2-115 board with DCC AD/DA daughter card

Honored Contributor II

Hi all. 


I am trying to implement a DDS with altera DE2-115 board. I want to use only the DAC of the daughter card. My codes run, no errors, in modelsim I can see the input thats gonna go in the hsmc interface. Its all fine, but I get no output from the DAC output co-ax when I connect it to an oscilloscope. 


I downloaded the DE2-115+DCC AD/DA demo that was available in the website. That runs fine, and I get the output from the DAC output channel as its supposed to. But when I input from my file I dont get anything out. Nothing. Not even a wrong signal either. Just noise. I should get something! 


Can anyone provide any insight in this? Thanks in advance. Any suggestion would be helpful.
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2 Replies
Honored Contributor II



1. Have you established common ground between oscilloscope and Board? 

2. Have you used proper clock frequency based on the DAC Spec? check the frequency of your design and the data rate/Fclock of DAC? 

3. For debugging you can use signal tap. 

4. Also, try by hardcoding the digital inputs like 0000,1000 & 1111 so that we can see the change in levels also set oscilloscope in capture mode for the level required. 


Best Regards, 

Anand Raj Shankar 

(This message was posted on behalf of Intel Corporation)
Honored Contributor II

Hi again 


I am finally getting some output in the oscilloscope, I had to make some adjustments in my code. But I find the DAC output signal is better for lower frequency, the signal degrades for higher frequencies. I have seen this in the case of the signals generated in the demo version too. The DAC spec mentions the max clock can be 275 MHz, doesnt mention any minimum. I tried doubling the DAC clk input (100MHz), doesnt improve much. 


Can you suggest any way which can improve the signal in higher frequencies? 


Thank you so much!