[SOLVED] Why remove scan chain before the placement?

Status
Not open for further replies.
A

akhil_psm

Newbie level 4
Joined
Dec 1, 2019
Messages
5
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Location
Bengaluru
Activity points
30
Regarding Scan Chain, why are we remove scan chain before the placement? and why are we reordering scan chain after the placement?
 
Last edited by a moderator:

Stitching scan chains before placement will not be optimal as placement locations determine the optimal way to stitch scan chains.
 

thank you for your response.
You said "not be optimal as Placement location" means?
 

akhil_psm said:
thank you for your response.
You said "not be optimal as Placement location" means?
Click to expand...

the goal of the placement tool is to minimize wirelength. if you have the scan chain already accounted for, the tool might mistakenly place the cells to try to minimize the scan-chain length. this is backwards. placement should work on minimizing wires that touch cells in critical paths. scan chain order doesn't matter, you can assign it later when you are done with placement.
 
Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…