This may be a Ptolemy question:
I need to generate an Eye diagram using a DDR (double-data rate) source, where the data is clocked on both the rising and falling edge of the clock. Built-in sources like VtBitSeq and VtLFSR don't seem to have the flexibility. Any examples of this in the filing cabinet?
-- Gary Otonari
I need to generate an Eye diagram using a DDR (double-data rate) source, where the data is clocked on both the rising and falling edge of the clock. Built-in sources like VtBitSeq and VtLFSR don't seem to have the flexibility. Any examples of this in the filing cabinet?
-- Gary Otonari
I[1,0] = setDT(0.0)
I[2,0] = -vout/Rout
Trig[1] = _xcross(1,0.5,0)
vout = if(_lfsr(1,Seed,Taps) = 0.0) then Vlow else Vhigh endif
The third parameter of the _xcross() function determines whether it will trigger on the negative edge (-1), positive edge (1) or both edges (0). If you needed different threshold levels for the two edges, you could do something like
Trig[1] = _xcross(1,RiseThresh,1) + _xcross(1,FallThresh,-1)