ttxs
Junior Member level 1
I am new to this field and I don't have a good understanding of the flow.
Could anybody help me to understand LEF, DEF, QRC Techfile and Capacitance table files?
My current understanding is that:
(1) LEF has "cell level" information, while DEF has "floorplan level" information. In this sense, I guess DEF is a higher level description of a design than LEF.
(2) QRC tech file, I am not quite sure what it is, and I guess it is like LEF, which is on a lower level than DEF... I am not sure what Capacitance table file is at all.
The main reason why I want to learn about the above relations is that, I came across two concepts: "pre-route extraction" and "rc-grid density computing", which seem to have a lot to do with LEF, DEF, QRC techfile and Capacitance table files.
My current understanding is that:
(1) techfile extraction (SoC Encounter will generate patterns.out log file) deals with LEF and QRC techfiles. It is a low level extraction.
(2) rc-grid-density computing (by Encounter command "peGetGridCorrelationData") deals with DEF and floorplan. It is a high level extraction.
I don't know why there is a keyword "grid". But I guess "pre-route extraction" is made of the above two operations.
Is the above understanding correct? I have a lot of separate pieces, but I can never put them together for a complete story :-(
Could anybody help me to understand LEF, DEF, QRC Techfile and Capacitance table files?
My current understanding is that:
(1) LEF has "cell level" information, while DEF has "floorplan level" information. In this sense, I guess DEF is a higher level description of a design than LEF.
(2) QRC tech file, I am not quite sure what it is, and I guess it is like LEF, which is on a lower level than DEF... I am not sure what Capacitance table file is at all.
The main reason why I want to learn about the above relations is that, I came across two concepts: "pre-route extraction" and "rc-grid density computing", which seem to have a lot to do with LEF, DEF, QRC techfile and Capacitance table files.
My current understanding is that:
(1) techfile extraction (SoC Encounter will generate patterns.out log file) deals with LEF and QRC techfiles. It is a low level extraction.
(2) rc-grid-density computing (by Encounter command "peGetGridCorrelationData") deals with DEF and floorplan. It is a high level extraction.
I don't know why there is a keyword "grid". But I guess "pre-route extraction" is made of the above two operations.
Is the above understanding correct? I have a lot of separate pieces, but I can never put them together for a complete story :-(