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What exactly is Clock Shielding and its functions?

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sree205

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Re: Clock Shielding

insertion of additional VDD and GND wires to reduce inductance in the clock wires.
 

badola

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Re: Clock Shielding

shree can u please some more light on dis topi
 

vlsitechnology

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Clock Shielding

sree could u please elaborate more on this topic?
 

useless_skew

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Re: Clock Shielding

Since clock nets are the worst aggressors, we shield so that the signal nets are not affected due to crosstalk.
 

wkong_zhu

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Clock Shielding

Clock is the most important signal in Digital circuits. So clock shielding is used to pretect clock from interference.
 

kumar_eee

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Re: Clock Shielding

Guys, we know about clock shielding. What are all the changes that we do in Layout?..

I heard that VSS is placed on both the sides of the Clock.. Is it so?.
 

layoutmaster

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Clock Shielding

There are a lot of techniques in order to avoid crosstalking from clock lines to other signal ones...

The faster, easier and simpler is just to draw the clock lines appart from the other signals, but this is sometimes too much area consuming.

One better solution is to surround the complete clock lines path by GND connected substrate contact paths, that way all the noise the clock lines could be generating is immidiately collected by the surrounding "barrier". It's recommended to do it so like a "ring" all arround the clocks generation block.

Last by not least, watch out if you have to cross the clock lines... ideal solution to that is to shield the clock with GND and make the cross above the shield...
 
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