Hello, I'm most likely having a clock issue because I cannot get any data transfers going between the USRP2 and GTPs on the V5. A few questions:
- I'm not quite sure I understand the 10MHz reference clock idea, or its usage; I looked through the HDL and everything on the FPGA is running at 100MHz. - I assume I will not need to provide this reference clock if the USRP2 is the driver given that sd_gentest appears to do so in the main functions clocks_mimo_config. Either way I'm using the SAS to quad SATA cable so the clock isn't even transferred to the GTPs (literally, it's supposed to derive it from the data). - My only clocking options on the GTP's are 150 or 75MHz. I'm not sure if I should clock the USRP2's FPGA or the reference differently to match this. Any help with the clocking scheme would be much appreciated. Thank you. Charles On Fri, Nov 27, 2009 at 4:20 PM, Charles Irick <cir...@gmail.com> wrote: > On Thu, Nov 26, 2009 at 4:47 PM, Matt Ettus <m...@ettus.com> wrote: >> Yes, you'll need to do firmware. If you just modify the main() function to >> set the loopback, it doesn't matter which firmware you start with. > > The closest thing I can find is the following: > output_regs->serdes_ctrl = (SERDES_ENABLE | SERDES_RXEN | > SERDES_LOOPEN); > I tried pasting that line into main() of sd_bounce assuming that > SERDES_LOOPEN was the loopback parameter. > I'm not getting anything back on the V5 side so if that function is > correct then it is probably some type of clocking issue. > >> BTW, I don't know how you intended to physically connect the boards. The >> best long term solution is to have your own custom board which implements >> the connections we use (SAS). In the short term, you can buy a SAS to quad >> SATA breakout cable. This would connect right to the SATA headers on many >> FPGA eval boards. >> >> Matt > > Right now this is what I'm doing. SAS to quad SATA breakout. I'm using > Lane 1 to connect to the V5 board. Are there any particular > disadvantages to this solution that made you suggest a custom board? > > Charles > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
