Crosstalk issue and prevention techniques | Crosstalk delay | Shielding of net | part-2

[@maltikumari8677]

Very helpfull, very clearly you have described each and every step ..

[@TeamVLSI]

Thank you @Malti, Its our pleasure. Keep watching, commenting and sharing. There are lots of video similar to this in our channel.

[@rbhavsar]

Nice explanation sir. One query which is not discussed in video. What will be effect of crosstalk on common clock path.? I mean to say if any crosstalk effect occur on common clock path then how timing will be effects.? Please clear it. @Team VLSI

[@TeamVLSI]

I believe there will no impact on the timing calculation if crosstalk is on the net before the common clock point.

[@chintu494]

Sir, Nice explanation sir... one query sir that how asymmetric signal triggering helps to reduce the crosstalk induced delay in interconnects? Thank you sir

[@Akk-ei9uw]

can you suggest a tool to find out crosstalk in the layout drawn? is there any opensource tools? What will be its input?

[@MBm107]

why we only shield for top metals even through same net connected from lower metal to higher metal

[@TeamVLSI]

Sorry, I am not much sure about your query, but fact is longer the length and victim and aggressor interaction , higher would be crosstalk and requirement of shielding is high there.

[@habibakhatunnesaragi6259]

Which text book is good ....for this kind of topics sir.ur explanation is best sir.

[@TeamVLSI]

Hi Habiba I mostly refers the class notes of various eminent professors all over the world. Initial days of my M.Tech I read almost all good books in this field but currently I do not get time to read all those. Some reference books are mentioned in the description of video. Thanks

[@vamshireddy9392]

sir,this video very helpful but i have a doubt that why inductive coupling is not considered pleases explain

[@TeamVLSI]

Because is has negligible effect.

[@vamshireddy9392]

@@TeamVLSI at high frequencies like 20ghz is there any effort?

[@aakashek8526]

Tjank you very much sir

[@TeamVLSI]

Most welcome

[@Narennmallya]

but sir in prevention technique, increase drive strength of victim, for slew reduction and fast switching---> wont it impact on more dynamic power dissipation and also leakage? Let me know if thats the tradeoff between crosstalk and power in this scenario

[@venkateshsanagala8287]

Sir can u upload some videos on analog layout

[@TeamVLSI]

Hi Venkatesh Check the link bellow of previously uploaded some videos on layout design in our channel. kzbin.info/aero/PLC7JCwKQnjL5fR-0F8DPZYUbZVG81PC5E Right now I am working on digital design only.

[@venkateshsanagala8287]

@@TeamVLSI sir I need complete information on some topics like matching, STI,LOD, floor planning steps

[@TeamVLSI]

Sorry Dear, I have not much more experience on said topics

[@bhanukallepalli2676]

Hi Sir, Very nice explanation. I have one doubt.. When we use ground as shield. There will be a chance we will get potential difference between victim and shield net then the cap between this will not try to charge and create negative glitch in victim node? pls help me understand this.. Thanks

[@TeamVLSI]

Thanks Bhanusri. The question is not very clear to me. What what is understood on that basis I would say. 1. Yes a varying potential could developed between the grounded shielding net and victim net as well as aggressor net if victim or aggressor net is not at constant low. 2. There will be mutual capacitance also. 3. But the shielding net is strongly connect to ground, So it is not easy to create any glitch in the shielding net. Hope I have answered you doubt.

[@bhanukallepalli2676]

​@@TeamVLSI ​ @Team VLSI Thanks for the reply. My question is related to what you have explained only. But as regard your reply: 1. Why strongly connected ground can help us? or how we are getting advantage by connecting shields to DC Voltage?

[@TeamVLSI]

Because if a net is connected directly to VSS or VDD it's potential could not be changed by the other signals due to strongest crosstalk.

[@bhanukallepalli2676]

@@TeamVLSI okay got it. Thanks

[@Narennmallya]

so negative crosstalk is actually improving the design?

[@pavankumarVilasagar]

On what basis, Tool decides aggressor and victim nets?

[@TeamVLSI]

Hi Pavan, I have logic on mind, but let me verify first. Meanwhile you can let us know what you think.

[@pavankumarVilasagar]

@@TeamVLSI I think, in the timing window, whichever signal has better slew(fast switching) will become aggressor.

[@pavankumarVilasagar]

What is your logic?

[@TeamVLSI]

Hi @Pavan Consider following situations 1. If a net has constant logic than it will not be an aggressor. Will it be victim? --> depends on the effect of aggressor on it. 2. Two very close nets switching and having almost equal slew rate. Can both be victim?? or both aggressor?? I think YES. Since we have issues with victim nets and have to fix the victim nets only. So the algorithm should consider each net as a victim run the analysis and find the effect of crosstalk on it and report each critically affected nets. "These are my opinions, What is the exact algorithm for the tools, I have not got a chance to see this "

[@pavankumarVilasagar]

@@TeamVLSI Nice explanation

[@nishadpadariya5341]

1. which is more effective to avoid crosstalk effect, NDR or Shielding ?

[@TeamVLSI]

I think, Shielding.

[@pavanibanoth7774]

Hi Sir, How can we identify which net is acting as aggressor and which net is victim?

[@TeamVLSI]

Thanks Pavani, for asking a really good question!! Kindly read the comment section of this video, We have already discussed this question with Pavan.

[@habibakhatunnesaragi6259]

Sir have u explained any placement ...with any vedios kindly share sir.

[@TeamVLSI]

Not in details, explained just in brief in the bellow link. kzbin.info/www/bejne/inXZomSei72tiMU