Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Liberty format capacitance definition

Status
Not open for further replies.
B

battosai

Newbie level 4
Joined
Dec 12, 2012
Messages
6
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,283
Location
Switzerland
Activity points
1,340
Hello

I am currently composing a liberty timing file for an analog block to be used in a larger digital simulation. The pin description for most pins are only described by their direction, capacitance and rise_ -and fall_capacitance. What I can't figure out is how these latter values are defined? Should these values represent the equivalent capacitance that generates the same rise and fall times?

Code C - [expand]
1
2
3
4
5
6
7
8

pin (AdcEnQxSI) {
        direction : input;
        capacitance : value;
        rise_capacitance : value;
        rise_capacitance_range (value_min, value_max);
        fall_capacitance : value;
        fall_capacitance_range (value_min, value_max);
    } /* End Pin */
 

can you please specify as in which tool you use, additional details.

I think you can simply ignore these as these are mostly done /created by tools like Liberate/ELC.... it is not something to be focussed unless you have a specific problem.
 

I am not using a specific tool to create the .lib file..

I am using cadence ADE to simulate the analog block. The simulation is controlled by an ocean script to iterate through all corners and list items to be specified in my timing arcs and. The results are then formatted for the lookup tables in the .lib file and written to a file.
The .lib file is then written by hand.. hence my question..
 

1-The liberty is not usable for digital simulation. The liberty is atiming/area/cap/trans/power information's for synthesis/PnR/STA tools.
2-The liberty format is describe here www.opensourceliberty.org.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top