Louis and others, Note that Marco's script modifies the DCM/MMCM configuration that I was referring to, so running his script should solve the problem. You can look at the source to see how it works. It just modifies the word HIGH in adc_interface.vhd to LOW. Glenn
On Tue, Jan 24, 2012 at 7:30 AM, Louis Dartez <louisdar...@gmail.com> wrote: > Hello Glenn, Marco, > > Thank you for your quick replies. I'll be stopping by the lab this > afternoon to give your suggestions and try. > > Glenn: I'll look around for the DCM/MMCM configurations and I'll let > you know where I find them if I do. > > Marco: thank you for the m file. I haven't looked at it just yet but > I'll give it a try when I get to the lab. > > I appreciate your help. > > --Louis P. Dartez > On Jan 24, 2012 8:53 AM, "Marco Bartolini" <mbartol...@med.ira.inaf.it> > wrote: > >> Hi Louis, >> I had your same problem some time ago. I had written a matlab function >> "lower_freq.m" that you can find attached, the code should be self >> explanatory ... and i don't remember the details >> basically you should compile your design with bee_xps up to "Copy base >> package", invoke lower_freq on the target directory, and terminate the bof >> file generation with bee_xps. >> >> hope it helps >> Marco >> >> >> >> >> Il giorno 23/gen/2012, alle ore 23.57, G Jones ha scritto: >> >> Hi Louis, >> The problem is probably that the DCM/MMCM has various configuration >> parameters which have default values for the clock speeds most commonly >> used for CASPER designs. To run at lower speeds, you'll need to tweak these >> values. I thought they can be found in the XPS_ROACH_base/data/system.ucf >> file that is generated for your design, but I'm not seeing it there right >> now. Perhaps someone else can guide you to the location of the parameters >> if you don't find them first. >> Glenn >> >> On Mon, Jan 23, 2012 at 2:46 PM, Louis Dartez <louisdar...@gmail.com>wrote: >> >>> Hello fellow CASPERites, >>> >>> >>> I've been trying to modify the wideband spectrometer tutorial >>> to have the MSSGE block clock rate set to 50 MHz and, following the 4 to 1 >>> rule, the ADC running at 200 MHz. Simulink complains about timing errors >>> when I try to do this. Is there another parameter that I'm forgetting about >>> and need to change? Or is there some lower limit for the ROACH clock rate? >>> I figured that as long as the adc is clocked at 4x the roach rate then I >>> should be able to lower both of them as long as I keep them at the same >>> ratio. >>> >>> Any thoughts? >>> >>> -- >>> -- Louis Dartez >>> (956) 372-5812 >>> Arecibo Remote Command Center Scholar >>> Center for Advanced Radio Astronomy >>> University of Texas at Brownsville >>> >>> >>> >> >> -- >> Dr. Marco Bartolini >> I.N.A.F. - I.R.A. >> National Institute for AstroPhysics - Institute of RadioAstronomy >> Medicina Radiotelescopes >> Via Fiorentina, 3508/B 40059 - Medicina (BO) - Italy >> Phone: +39 051 696 5834 Email: mbartol...@med.ira.inaf.it >> Fax: +39 051 696 5810 Web: http://www.med.ira.inaf.it >> >> >>
