Drive strength

[shree@12]

Why in the design we do not use "D0" & "D20" drive strength cell in design?

 

[dick_freebird]

Couldn't tell you, I have never seen this notation nor
what it's supposed to mean.

If those "D0" are the min-W versions of some cell, maybe
somebody already has figured out they're timing hazards
waiting to happen until you've already routed the part and
gotten the true parasitics-driven delays to fail timing.

That's always fun and best left until after investing much
design effort. Uh, huh.

If "D20" is 20X min W then maybe that also pushes on
cell width without much benefit (unless you know a priori
about a specific wireload being heinous).

But if you want more than wild speculation from decades
past, you'd best bring some more than "gimme gimme"
with a side of not-a-clue..

 

[shree@12]

Couldn't tell you, I have never seen this notation nor
what it's supposed to mean.

If those "D0" are the min-W versions of some cell, maybe
somebody already has figured out they're timing hazards
waiting to happen until you've already routed the part and
gotten the true parasitics-driven delays to fail timing.

That's always fun and best left until after investing much
design effort. Uh, huh.

If "D20" is 20X min W then maybe that also pushes on
cell width without much benefit (unless you know a priori
about a specific wireload being heinous).

But if you want more than wild speculation from decades
past, you'd best bring some more than "gimme gimme"
with a side of not-a-clue..

here D0 means zero drive strength cell

 

[KlausST]

Hi,

Shure this belongs to "elementary electronic questions"?

Shure you don´t need to explain what all this belongs to (software, HF design ... or whatever) and what software or documents you refer to?

I mean I am quite familiar with "elementary electronics" .. but still I have no clue what you are talking about.
Maybe I´m not the only one.


Klaus

 

[shree@12]

Hi,

Shure this belongs to "elementary electronic questions"?

Shure you don´t need to explain what all this belongs to (software, HF design ... or whatever) and what software or documents you refer to?

I mean I am quite familiar with "elementary electronics" .. but still I have no clue what you are talking about.
Maybe I´m not the only one.


Klaus

I am asking that in the vlsi design , we do not use zero drive strength cell in design why?

 

[dick_freebird]

Well, zero drive whatsoever would just be baggage (like
trying to fine-align some edge-pair through burden-tweaks
in the logic netlist).

But sometines "zero" is not "zero" but rather, "smallest legal"
(does your index start at 0, or 1?). A zero drive strength gate
would (you'd think) not have an output pin. If zero is zero.