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.

set_driving_cell and set_input_transition usage

Status
Not open for further replies.

ajeshar

Newbie level 2
Newbie level 2
Joined
Dec 3, 2010
Messages
2
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,296
Hi,

I want to specify set_input_transition and set_driving_cell in a design.

My doubt is, is there a way to specify the input transition at the input of the driving cell(which I specify using the set_input_transition command)

Also, in the presence of set_driving_cell how is the transition at the input port computed

Any feedback will be helpful.

Regards
Ajesh
 

Typically you would use the set_input_transition on a pin that you are unsure of the source. This is a great way to constrain maximum transition time at a top level pin
(i.e. at the pad). set_driving_cell works best when used in conjunction with -lib_cell option. This allows synthesis to accurately gauge the transition time by taking into account the capacitive load of you driving cell (this information comes from the liberty files .lib or .db).

You can use set_input_transition to define the slew rate of your driving cell, and then use the set_driving_cell -lib_cell option to constrain the path in question.
 
Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top