I think the tx overflow will be OK since the FPGA won't try to send more than 10 Gbps. I think the "rx overrun" flag would be more interesting. But probably best to check both of course! :)
Is the X engine clock an exact copy of the F engine clock (i.e. a common clock that goes through a massive splitter) or just a clock of the same frequency locked to the same reference (but not the exact same clock)? Things get more complicated once you run F and X at different rates, so I wouldn't recommend that path if you can avoid it. HTH, Dave > On Mar 12, 2018, at 22:01, Homin Jiang <[email protected]> wrote: > > Hi Dave: > > Thanks of prompt response and suggestion. > The X engine is running the same clock as the F engine, 2.24GHz/8 = 280MHz. > Perhaps I should increase the clock in X engine ? > Yes, there is Tx overflow flag in the model, it will be the first thing for > me to check. > > best > homin > > > > On Tue, Mar 13, 2018 at 12:42 PM, David MacMahon <[email protected] > <mailto:[email protected]>> wrote: > Hi, Homin, > > The first thing to do is figure out where packet loss is actually happening. > The fact that you have to reset the 10G yellow blocks to get things going > again suggests that the X engines are not keeping up with the data rate > (since the F engines will happily churn out 8.96 Gbps data regardless of the > receivers' states and the X engines will happily churn out data regardless of > the PC's state, it seems that the only way for the 10 GbE blocks to get > confused is if the X engines are not keep up with the incoming data rate). I > assume the F engine ROACH2s are being clocked via their ADCs. How are the X > engine ROACH2s being clocked? > > Assuming the F-to-X packets are going through a switch, you could query the > switch to see what it thinks the incoming and outgoing data rates are on the > various ports involved. > > Does your design have any way of capturing the overflow flags of the 10 GbE > cores? > > Dave > >> On Mar 12, 2018, at 19:39, Homin Jiang <[email protected] >> <mailto:[email protected]>> wrote: >> >> Dear Casperite: >> >> We have been deployed a 7(actually 8) antenna packetized correlator on Mauna >> Loa Hawaii. Running at 2.24GHz clock, that means 8.96 G bits per second for >> each 10G ethernet. The packet size is 2K. There are 8 sets of ROACH2 as F >> engines, the other 8 sets of ROACH2 as X engines. Data packets from F to X >> looks fine, the problem of lost packets is the integration data from X >> engine to the computer. The 10G yellow blocks in X engines handle the >> incoming data packets from F engine at the data rate of 8.96 Gbps, and >> output the integration data to PC, the outgoing data rate depends on the >> integration time, usually it is longer than 0.5 second. The syndrome is that >> packets lost happened by specific X engines after 10,20 minutes or couple of >> hours. Once it happened, we reset all the 10G yellow blocks in F and X, then >> the system revived. >> >> I have no idea about the 10G ethernet yellow block. Any comments of >> suggestions are highly welcome. >> >> best >> homin jiang >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "[email protected] <mailto:[email protected]>" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] >> <mailto:[email protected]>. >> To post to this group, send email to [email protected] >> <mailto:[email protected]>. > > > -- > You received this message because you are subscribed to the Google Groups > "[email protected] <mailto:[email protected]>" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To post to this group, send email to [email protected] > <mailto:[email protected]>. > > > -- > You received this message because you are subscribed to the Google Groups > "[email protected]" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To post to this group, send email to [email protected] > <mailto:[email protected]>. -- You received this message because you are subscribed to the Google Groups "[email protected]" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected].
