Answers Database

VERILOG-XL: SDF Annotator gives "SDFA Error: Could not find path IN to OUT"


Record #2750

Product Family:  Software

Product Line:  Cadence

Problem Title:
VERILOG-XL: SDF Annotator gives "SDFA Error: Could not find path IN to
OUT"



Problem Description:
Keywords: verilog simulation, timing simulation, SDF

Urgency: Standard


Upon doing a timing simulation in Verilog-XL, you may receive
the following errors if you also use the +delay_mode_unit
option:

	  time_sim.sdf	L18: SDFA Error: Could not find path IN to OUT in instan
ce test.uut.p1$i27

	  time_sim.sdf	L183: SDFA Error: Could not find path CTL to OUT in inst
ance test.uut.\p1$i29.GTS.TRI_737

	  time_sim.sdf	L233: SDFA Error: Could not find path IN0 to OUT in inst
ance test.uut.\p1$i40/p1$i23/p1$i3

	  time_sim.sdf	L281: SDFA Error: Could not find path ADR0 to OUT in ins
tance test.uut.\p1$i40/p1$i20/i18

	  time_sim.sdf	L295: SDFA Error: Failed to find WIDTH timingcheck

	  time_sim.sdf	L297: SDFA Error: Failed to find SETUP timingcheck



You may not use the +delay_mode_unit option while also doing a
SDF annotation.  The SDF file is the Standard Delay Format,
file, and it contains all the timing information for the
design).



Solution 1:

If your goal is to do a simulation with unit delays on a
Verilog file generated to do timing simulation, edit the Verilog file (.v) and c
omment out the line that calls the
"$sdf_annotate" function with a double slash (//).

Example:

In the file "time_sim.v", generated by ngd2ver by the M1
tools when doing a Verilog timing simulation, you will find:

.....

    initial $sdf_annotate("time_sim.sdf");

Change this to:
    // initial $sdf_annotate("time_sim.sdf");


Remember to comment out the "initial" statement
associated with this function call when you comment the
sdf_annotate function call.

If you wish to toggle between full timing and unit delay
simulation without having to modify your Verilog netlist each
time, see (Xilinx Solution #2650) for instructions on
specifying the SDF file from the command line.












End of Record #2750