liberty2json

Commandline tool that converts Synopsys Liberty format to JSON, which is inspired by google skywater project.

Why liberty2json

Liberty file is commonly used in most of state-of-art commercial P&R tools to store library and cell timing,power and area(PPA) information, usually in single file. And it's not suprised to see liberty file in advanced technology node can reach to GBs. To avoide frequently accessing large file, it's necessary to spilt them into multiple small .lib, ie, one common.lib to store basic technology information and many cell.lib to store separated cell information. This is also liberty2json considered.

Second, why use JSON instead of liberty? JSON is an ambiguous data format that widely used in many field and many programming language naturally support parsing this format. So I choose this file type as a alternative to .lib to make liberty file more easy to use.

Liberty Syntax

The basic syntax of liberty format is consisted of attribute and group, where attribute syntax as

Attribute:
key: value

and group syntax as

Group:

named_group:

class(name){
	attribute1,
	attribute2,
	...
	group1-withoutname
	group2-withoutname
	...
}

or 

unnamed_group:

class(){
	attribute1,
	attribute2,
	...
	group1-hasname
	group2-hasname
}

In attribute, the value can be descripted in different ways, like simple string, float number, or quoted string.

Usage

• Install liberty2json

cargo install liberty2json --git https://github.com/erihsu/liberty2json --branch main

• Convert liberty

liberty2json -o output_folder someliberty.lib 

with tracing log

RUST_LOG=trace liberty2json -o output_folder someliberty.lib 

if you not specify output_folder path, tool use the path of liberty file to generate json.

Check wiki for details

Reference

liberty syntax reference