--- Quote Start ---
First, if you have a look at the DAC904 datasheet, you will see that the DAC loads the data values on the rising edge of the clock, so it's not a good idea to have a signal pin at the same frequency than your clock. It should be at most half the frequency.
Second if you have another look at the DAC904 datasheet, you will see that TI made something very stupid: they called "Bit1" the MSB and "Bit14" the LSB. So in fact you need to connect your data vector backwards: dac[0] to Bit14, dac[1] to Bit13, dac[2] to Bit12 etc.... right now you are toggling the least significant bits right now, which are unlikely to change the DAC output enough for you to see it on the scope. Try to toggle Bit1 and Bit2 instead, for example, and see if there are any changes.
--- Quote End ---
I used the oscilloscope to check the frequency of LSB bit (pin 14 of DAC). its frequency is 1Mhz. So, it just take 0.0164s for counting from 0 to 16384 ( the output voltage should be from 0 to 5v AC). So, I think I can "observe" the change in the oscilloscope. I input the clock for the DAC of 5Mhz. but the result is almost the same. the output voltage is always 0V before and after the transformer
I wonder the DAC 904 on this board is broken. So if you have any FPGA stratix board. pls help me> I will send the .sof file and the project file. could you check for me on your board?
Honored Contributor
