Differnce between Hvt and Lvt cells

[natg9]

hvt lvt

Hi

Can anybody tell me how do i differentiate between the hvt and lvt cells apart from their timing information presented in the .lib files

Please attach some supporting documents if possible
Are there any structural differences between the two ??


thanks in advance

Regards
natg

 

[balasub]

hvt cells

refer to this for some basic simple explanation

 

[natg9]

lvt hvt

thanks

 

[kumar_eee]

hvt vs lvt

If you open both LVT & HVT lib cells, you can find a layer difference. That layer is VTH(HVT Lib) & VTL ( LVT lib)... Normal SVT lib doesn't contain these layers..

 

[natg9]

what are hvt and lvt cells

hi Kumar

thanks for your reply ,but could u plz elaborate on that as i looked into the libs but didnt find any such layer information

could u direct me to some link containing brief description on it or it would be gr8 if u put it in your words

what is this layer ??

regards
natg

 

[kumar_eee]

hvt/lvt

Hi,
I dont have any link or doc.. I worked in std cell lib development for some time.. from my experience I replied to your query....

If you were not able to see any HVT or LVT layers, then How it is differentiated from SVT lib?.

Rgds,
Kumar

 

[natg9]

lvt cells

hi Kumar

thanks for your reply
well i am a PD engineer so i dont have any information about the layer and and other things that goes into the making of these cells


all i am given is the timing library of these cells
i differentiate the cells based on the timing information provided in the .lib files so i am not aware of the layers used in the making of these cells below METAL1

thats where this question arrises of how the different cells are created having different timings

well i hope i have made my question clear and that u wud certainly revert back with an elaborate reply

thanks

 

[kumar_eee]

difference between rvt,hvt,lvt

The HVT/LVT libs are implemented with the VTH/VTL layers.. Whenever the characterization team extract the layout, this VTH/VTL layer also accounted.. Moreover the respective spice models also used while generating the .lib files... when you simulate with HVT/LVT spice models, the delays & timings also will be modified accordingly..

see, HVT/LVT layers r used to show that the area covered by these layers are dipped more ion implantation. That means, the physical characteristics of the OD(Active area) are changed thru more/less ion implantation...

Hope this clears your doubt..

 

[natg9]

hvt lvt microelectronics

hi Kumar

Thanks for your reply
it has cleared my doubt to a lot of extent

i request you to give me some more inforamtion on it


thanks & regards
natg

 

[kumar_eee]

lvt 142

right now I dont have any material on this topic.. I will inform you if I got something.

 

[natg9]

lvt vs. hvt

Thanks a lot for all the help

can i have your personal mail id ??

i wouldnt bug u


regards
natg

 

[kumar_eee]

hvt svt lvt library

its kumar.kuppusamy@gmail.com

 

[rtl2gates_user]

hvt and lvt cells difference

natg9,
The only way that is hvt and lvt cells are differentiayed in the timing files is by the cellname. The timing files will not have layer names and it would carry process models information. Typically we would name it as AND2X1HVT , AND2X1LVT. However the extraction decks user a layer to recognize if it is an HVT or and LVT device. This could be anything based on your process profile. To get more answers and documents please post this question on "www.rtl2gates.com"

Thanks

 

[onlymusic16]

svt and lvt cells difference

If you want to see the difference, you should open the layout. You will see a mask layer difference.

 

[hiral.kotak]

difference between hvt and lvt cells

Hi,

HVT = high V threshold. Can be used in the path where timing is not critical. So by using HVT cells we can save power.
LVT - Low V threshold. One should use these cells in timing critical paths. These cells are fast but , comsumes more power due to its leakage. So it will consume more power. So use only when timing is critical.
SVT- Standard V threshold. Best of both world. Medium delay and medium power requirment. So if timing is not met by small magin with HVT, you should try with SVT. And at last LVT.
So, if you are using a multivt library for your design implementation, you can choose the appropriate vt cells as per whether the design is timing critical or power critical. It is better to use low vt cells for timing critical path and high vt cells for non-timing critical path so that power target can be achieved.

Moreover for a low power desig you can apply the multivdd concept, diferent voltage domains and use of power gating.


It may help u.

Thanks..

HAK..