Hi everyone, I'm seeing some strange behavior in the ADC block in 10.1 that's part of a DDC design I'm working on. The board is the "classic" iADC (ADC2x1000-8). The input clock 400 MHz, the iBOB is running at 100 MHz and interleave mode is turned off. I put a SNAP block directly on the output of the ADC by concatenating the four 8-bit samples. The output traces a sine wave except that samples i2 and i4 are a constant, namely 32 for the I input and about 66 for the Q input when I changed my model to get data second input. I've done several captures, and it's always the same value and always i2 and i4. I don't think it's an issue with the snapshot because looking at the output of the mixer also shows that the second and fourth data streams are constant. Could this be an issue with demultiplexing in the ADC?
Glenn, several months ago you mentioned that you were having trouble with the DDC in 10.1 and captured data ADC from the ADC directly. Did you see this problem with i2 and i4? (And btw, I'm also getting the strange mirrored output, but that'll probably be another email.) Here are a couple lines of my data (first column is sample number; ignore the columns with zeros; column 4 is the signed version of column 2): 0 47 0 47 0 1 32 0 32 0 2 45 0 45 0 3 32 0 32 0 4 43 0 43 0 5 32 0 32 0 6 38 0 38 0 7 32 0 32 0 8 32 0 32 0 9 32 0 32 0 10 26 0 26 0 11 32 0 32 0 12 18 0 18 0 13 32 0 32 0 14 9 0 9 0 15 32 0 32 0 16 0 0 0 0 17 32 0 32 0 18 247 0 -9 0 19 32 0 32 0 20 239 0 -17 0 Thanks! Laura
