Ha, thats my kind of progress. 800ms is about the sync rate I put in @ 800MHz ADC clock. I just used the ready-made sync_gen block, but I'll see if I did something stupid.
On 17 September 2012 15:56, Jason Castro <[email protected]> wrote: > Thank you all for your input. It's always nice to come into work on a > Monday and be able to hit the ground running! I loaded Jack's latest > tutorial 3 bof file and I got some interesting results. The spectrum slips > along the x axis 4 channels every 800ms or so. This slipping event is also > accompanied by about 10db of noise in the stop band of the signal. Please > see the following plots: > > ftp://ftp.cv.nrao.edu/NRAO-**staff/jcastro/CASPER/** > Spectrometer/Tutorial_3_**sliding_spectrum1.PNG<ftp://ftp.cv.nrao.edu/NRAO-staff/jcastro/CASPER/Spectrometer/Tutorial_3_sliding_spectrum1.PNG> > ftp://ftp.cv.nrao.edu/NRAO-**staff/jcastro/CASPER/** > Spectrometer/Tutorial_3_**sliding_spectrum2.PNG<ftp://ftp.cv.nrao.edu/NRAO-staff/jcastro/CASPER/Spectrometer/Tutorial_3_sliding_spectrum2.PNG> > > I'll dive into this and try to figure out what's going on, but extra eyes > are appreciated. > > Thanks, > > Jason Castro > NRAO > > > > > On 9/17/2012 8:03 AM, Jason Manley wrote: > >> On 17 Sep 2012, at 11:45, Jack Hickish wrote: >> >>> 2^27 isn't a valid sync period for tut3, which has an FFT ending in a >>> 10th order reorder >>> (https://casper.berkeley.edu/**memos/sync_memo_v1.pdf<https://casper.berkeley.edu/memos/sync_memo_v1.pdf> >>> ). >>> >> Good catch! This is what I get for copy-pasting that design from another >> :-/ >> >> Tut3 has been in use in CASPER for over 3 years now and I think you're >> the first one to notice! >> >> Jason >> > >
