Hello! Our group is testing a wireless OFDM MODEM (with RFIC board) FPGA board using LitePoint equipment. It can be connected via RF or baseband cable. We are checking PER by setting different data rates and Tx signal levels (dBV). The problem that's killing our efforts is "blue screen/reboot" on the laptop with MAC software once in awhile, actually almost every 10-20 minutes or so of testing. Some guys assume it's due to sensitive PCI connection between the FPGA board and MAC laptop, but they changed 2-3 cables and nothing helps. Is it Tx signal level (about -25..-30 dBV, set in LitePoint software) or something else? Is it something obvious we are missing, what could be the possible source of problems? Thank you in advance!
Testing MODEM FPGA - problems - HELP!!!
Started by ●October 17, 2007
Reply by ●October 18, 20072007-10-18
Dan Ocean wrote:> Hello! > > Our group is testing a wireless OFDM MODEM (with RFIC board) FPGA board > using LitePoint equipment. It can be connected via RF or baseband cable. > We are checking PER by setting different data rates and Tx signal levels > (dBV). The problem that's killing our efforts is "blue screen/reboot" on > the laptop with MAC software once in awhile, actually almost every 10-20 > minutes or so of testing. Some guys assume it's due to sensitive PCI > connection between the FPGA board and MAC laptop, but they changed 2-3 > cables and nothing helps. Is it Tx signal level (about -25..-30 dBV, set > in LitePoint software) or something else? Is it something obvious we are > missing, what could be the possible source of problems?Overheating? Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Reply by ●October 18, 20072007-10-18
> >Overheating? > >Jerry >-- >Engineering is the art of making what you want from things you can get. >¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ >Where would you think overheating could be? They replaced laptop with MAC software and we still see "blue screen" once in awhile. It seems that some values of the signal level cannot go with some SNR values when we are looking for required SNR (for some PER margin), but that's just a guess.
Reply by ●October 18, 20072007-10-18
On Oct 18, 12:03 am, "Dan Ocean" <oceansm...@gmail.com> wrote:> >Overheating? > > >Jerry > >-- > >Engineering is the art of making what you want from things you can get. > >=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF==AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF= =AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF=AF> > Where would you think overheating could be? They replaced laptop with MAC > software and we still see "blue screen" once in awhile. It seems that some > values of the signal level cannot go with some SNR values when we are > looking for required SNR (for some PER margin), but that's just a guess.Blue screens on Windows are caused by fatal errors that occur when code is running in kernel mode. For example, a buggy device driver can do this. I would suspect that the driver for your FPGA board might have some sort of an issue. One thing you can do is examine the output on the blue screen; it will tell you what driver caused the problem if this is the case. Then, you know where to investigate further. Jasno
Reply by ●October 18, 20072007-10-18
Dan Ocean wrote:>> Overheating? >> >> Jerry >> -- >> Engineering is the art of making what you want from things you can get. >> ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ >> > > Where would you think overheating could be? They replaced laptop with MAC > software and we still see "blue screen" once in awhile. It seems that some > values of the signal level cannot go with some SNR values when we are > looking for required SNR (for some PER margin), but that's just a guess."They replaced laptop with MAC software ..." Are you using a laptop or not? Laptops tend to overheat anyway when the processor is running full bore, and putting it on something soft (like a lap) can obstruct the vents. There are boxes with fans in them made to couple to some laptops. There's evidently a need. It's more likely that defective software will cause the OS to abort a program than to bomb the OS into a blue screen. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
