Answers Database
M1 : How to change speed grades (faster or slower) of your placed and routed design? How to recreate simulation and static timing models?
Record #2630
Problem Title:
M1 : How to change speed grades (faster or slower) of your placed and routed design? How to
recreate simulation and static timing models?
Problem Description:
Urgency: Standard
models for a different (faster or slower) speed grade of the same
placed and routed design (ie. 4005E-3 --> 4005E-2)?
Solution 1:
Static Delays (Creation of Simulation Models is Resolution 2)
=============
If you wish to see the overall design performance or wish to find
the static timing delays of paths with a different speed grade,
you can do so from either the graphical static timing tool,
"Timing Analyzer" or from command-line static timing tool,
"Trace" (trce).
Using Timing Analyzer:
---------------------
1. Load in design to be examined
2. Select from the menu: (Options --> Speed Grade)
<Select desired speed grade> --> OK
3. Perform design Analysis
Using Trace: Specify the new speed grade with the -s switch:
-----------
trce -s <speed> [other options] <design[.ncd]> [<constraint[.pcf]>]
Solution 2:
Timing Simulation Models
========================
In order to change speed grades and create a new simulation model. The
post-placed and routed design file need to be loaded into Epic so that
the delays may be re-calculated for the design file and subsequant
simulation files. The following steps assume that you have already
placed and routed the design as well as created a simulation model for a
previous speed grade of the same device :
From Design Manager:
-------------------
1. Open Flow Engine (Tools --> Flow Engine) and back up the
implementation steps so that the "Place&Route" step is completed
but the Timing portion is not. To back up the Flow Engine, either
select (Flow --> Step back) or depress the backward arrow button
until you are at the desired portion of implementation. Close the
Flow Engine.
2. Load design in Epic by selecting (Tools --> Epic) Design Editor.
3. Once the Epic Design Editor has loaded, select
(Misc --> Post Main Attrs...) From the Main Attributes Window,
Select the desired speed grade from the Speed selection box and
hit OK.
4. Save the design in Epic by selecting (File --> Save). Exit Epic.
5. Re-create the simulation model with Design Manager by opening the
Flow Engine (Tools --> Flow Engine) and finishing implementation
(Flow --> Run).
6. The up-dated simultion files should be created for the new speed
grade.
7. Re-run simulation.
From Command-line :
-----------------
1. Load placed and routed .ncd design file in Epic:
epic <routed design>.ncd
2. Once the Epic Design Editor has loaded, select
(Misc --> Post Main Attrs...) From the Main Attributes Window,
Select the desired speed grade from the Speed selection box and
hit OK.
3. Save the design in Epic by selecting (File --> Save). Exit Epic.
4. Re-run ngdanno on the newly written .ncd file from Epic:
ngdanno [-o <ngafile[.nga]>] [-p <pcffile[.pcf]>] <ncdfile[.ncd]>
[<ngmfile[.ngm]>]
5. Re-run the program to re-create the simulation model for your
simulator (ie. ngd2edif, ngd2xnf, ngd2ver, ngd2vhdl, etc.).
Use the same commandline as previously to recreate a similar
simulation file. Note: if a simulation file already exists, you
must use the -w switch to allow the software to overwrite the
previous design file.
6. Re-run simulation.
End of Record #2630 - Last Modified: 01/15/98 17:23 |
