AnsweredAssumed Answered

SI scope flatline in Boardsim, works in Linesim

Question asked by sbishop on Dec 9, 2014
Latest reply on Dec 9, 2014 by ed_bartlett

HI folks,


I'm having this problem in Hyperlynx BoardSim 9.0 (build 71131) with multiple designs


=  I create a new Boardsim board, translating a .DSN file (which was created in Boardstation) and do all the setup stuff, assigning models, etc.

=  I select a net or diff pair for SI simulation.  The net is highlighted, along with all the connected pins.

=  I run an interactive simulation in Oscilloscope.


On about half of the nets, everything works fine.  On the others, the scope shows me the expected waveform at the driver pin, but the waveform at the receiver pin is dead flat, zero volts, as though the receiver isn't connected to the net at all.  Now the weirder part:  If I export that net as a free-form schematic and open it in Linesim, the interactive simulation in Oscilloscope works just fine.


Normally, I'd categorize this as an annoyance, but now I'm trying to run the DDR wizard in Boardsim, and everything fails because of the nets with no connectivity.


I examined the DSN file to see if maybe the wire endpoints didn't exactly hit the pin centers or something, but everything looks correct there.


Any ideas on why this is happening?