kalar
Newbie level 5
Hi,
I manage to run gate-level simulation of my post-routed netlist with ncverilog, and i can observe the increased delay of all cells and nets at simvision. My only question is about the sdf statistics that ncverilog reports, as I would excepted 100% annotation but it reports only 2.67% for paths and 2.58% for tchecks.
About the design and the procedure: top.v is the post-routed netlist, tb.v is the benchmark where top.v is instantiated. Inside the top.v, the technology lib is included (lib.v). At tb.v, this is included too $sdf_annotate("./top_v3.sdf", my_testbench.add_top);. Sdf was created in Encounter.
I run ncverilog as follows:
Report of running ncverilog:
So my question is why the Annotated percentage is only abou 2 % and not 100%? At simvision I can see all the cells and nets to be annotated. In addition, what Path Delays represents (for sure not all the paths of my design, as it is a very small design)?
My best,
Harry
I manage to run gate-level simulation of my post-routed netlist with ncverilog, and i can observe the increased delay of all cells and nets at simvision. My only question is about the sdf statistics that ncverilog reports, as I would excepted 100% annotation but it reports only 2.67% for paths and 2.58% for tchecks.
About the design and the procedure: top.v is the post-routed netlist, tb.v is the benchmark where top.v is instantiated. Inside the top.v, the technology lib is included (lib.v). At tb.v, this is included too $sdf_annotate("./top_v3.sdf", my_testbench.add_top);. Sdf was created in Encounter.
I run ncverilog as follows:
Code:
ncverilog ./top.v \
./tb/tb.v \
+maxdelays \
+access+rw > log
Report of running ncverilog:
Code:
Reading SDF file from location "./top_v3.sdf"
Annotating SDF timing data:
Compiled SDF file: top_v3.sdf.X
Log file:
Backannotation scope: my_testbench.add_top
Configuration file:
MTM control:
Scale factors:
Scale type:
Annotation completed successfully...
SDF statistics: No. of Pathdelays = 11056 [B]Annotated = 2.67%[/B] --
No. of Tchecks = 15478 [B]Annotated = 2.58%[/B]
Total Annotated Percentage
[B]Path Delays[/B] 11056 295 2.67
$hold 383 0 0.00
$width 5872 200 3.41
$recovery 383 0 0.00
$setuphold 8840 200 2.26
So my question is why the Annotated percentage is only abou 2 % and not 100%? At simvision I can see all the cells and nets to be annotated. In addition, what Path Delays represents (for sure not all the paths of my design, as it is a very small design)?
My best,
Harry