What are tap cells and what is the usage of them?

[cj9404]

tap cell?

I took a look at the floorplan of one block i have, found that there are quite a lot of so call TAP cells been placed. could anybody explain to me what are tap cell and the usage of them?

Thanks,

 

[vinayshivakumar]

Re: tap cell?

It does some sort of substrate connection i think... BTW are you associated with TI ?

 

[kumar_eee]

Re: tap cell?

To Avoid Latuch up effects, we place TAP cells.

Its just establishing the subtrate & Bulk connection.

 

[vinayshivakumar]

Re: tap cell?

Kumar - one clarification - Dont the standard cells themselves contain the substrate and bulk connections ???? Or are these connections excluded from the cells ??

 

[forkschgrad]

Re: tap cell?

do u have good books or links discussing tap cells? tnx.

 

[kumar_eee]

Re: tap cell?

@vinayshivakumar,
Std cell doesn't contains these TAP connections. Actually you don't need to use TAP connection in all the cells. It will increase the cell area & as well as chip area. Normally we place a TAP cell for around 5 or more std cells combined while doing top level routing


@forkschgrad,
I don't have any documents regarding this. The above answer is from my real experience.

 

[vlsitechnology]

Re: tap cell?

Check out this matter it may help u
Bye

 

[vinayshivakumar]

Re: tap cell?

@kumar_eee
thanks
@vlsitechnology
Thanks. Which document did you pick this info from...
I had searched a lot for data on it , but never found any stuff....

 

[research235]

tap cell?

its from soc encounter user manual if I remember well

Suresh

 

[vlsitechnology]

yes suresh is right, I have picked from SOC Encounter user manual