Noise models

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Above high                                                                                              Above low
                            Below low                                                                                               Below high


Beyond the rails these are more critical part the block if its occurs there is high possibility of gate demands
Between the rails will have the power model files like ccs NLPM, etc., depends on the technology

To avoid Beyond the rails effect in the block:
For these beyond the rails first we will do some reliability checks then after will give some margin. which is not the part of the noise models 
margin setting will done manually for this models with the help of set_noise_margin command
How much margin ?
Its again depends upon the gate withstand effect  which will comes from foundry  its generally 30 to 40% of vdd.








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