Other Parts Discussed in Thread: CDCM7005, DAC5681Z
Hello,
I have used the TSW1400 to create a waveform with the DAC5681EVM board. A .csv file was created in MATLAB, and loaded into the High Speed Data Converter software. Its data rate was 250 mega samples per second. Once we got the register settings figured out, the waveform looked exactly like we wanted on the spectrum analyzer.
One odd but necessary part was setting the Y2 output (the one feeding back to the TSW1400) of the CDCM7005 to a 16 times divider.
I'm using a Cyclone V dev board now to try and recreate this waveform. I took the successful .csv file, converted into 2's complement memory file, and instantiated a ROM in the FPGA using it.
The FPGA code reads out the memory file and sends it to the DAC at 250MHz. I followed the Clock and Data Timing Diagram in Figure 42, page 34 of the DAC5681z datasheet. I made sure to save the DAC5681z register settings used with the TSW1400 and reload them for the FPGA. The only register change is reversing the data bus, due to the FPGA dev board HSMC pinout.
However, I cannot get the waveform to look anything close to correct. I'm using the same data to write to the DAC, but it's looking completely different.
Does anyone have any guidance?
Thank you!
