DE2-115 board with DCC AD/DA daughter card

[Altera_Forum]

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.

[Altera_Forum]

Hi, 

 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)

[Altera_Forum]

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!

[Owen-Tan]

Hi, a newbie here,

I'm currently working on my Final Year Project where I needed to do something similar to yours, except that I am using the DE-10 Standard Board instead of DE2-115. I'm wondering what did you change on your code to be able receive output in your oscilloscope? My modelsim simulation shows the signal I'm looking for but the oscilloscope receive no output at all. I have checked the pin mapping and the AD/DA card clock A and B over and over again but I cant seem to locate the issue. Mind sharing your solution?

Your help will be much appreciated, thank you very much!