Stats

  • Locked Locked
  • Replies 11
  • Subscribers 126
  • Views 22514
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

How can I automate noise margin calculation ?

marten

Hi all,

is there a way to automatically calculate the noise-margin of a given cell? For a single calculation I solve this manually by calculation the derivative of the output, and then determine V_IL, V_IH, V_OL, V_OH using the plot window.

Since I want to do Monte Carlo analysis, it would be better to have this automated. So, any suggestions from the community ?

Cheers,

Marten

Parents

  • Now I did the following:

    ;Dertermine input voltage, for which the derivative of the transferfunction crosses -1
    V_il=cross(deriv(getData("/out")), -1 1 'either )
    V_ih=cross(deriv(getData("/out")), -1 2 'either )

    ;Get the output voltage with respect to the calculated V_il, V_ih
    V_oh=value(getData("/out"), V_il)
    V_ol=value(getData("/out"), V_ih)

    ;Calculate Noise Margin
    NM_h=V_il-V_ol;
    NM_l=V_oh-V_ih;


    I am not sure about the first step, will there in any case only be two solutions?
    Maybe someone with more experience about cross() function can comment on this solution.

Reply

  • Now I did the following:

    ;Dertermine input voltage, for which the derivative of the transferfunction crosses -1
    V_il=cross(deriv(getData("/out")), -1 1 'either )
    V_ih=cross(deriv(getData("/out")), -1 2 'either )

    ;Get the output voltage with respect to the calculated V_il, V_ih
    V_oh=value(getData("/out"), V_il)
    V_ol=value(getData("/out"), V_ih)

    ;Calculate Noise Margin
    NM_h=V_il-V_ol;
    NM_l=V_oh-V_ih;


    I am not sure about the first step, will there in any case only be two solutions?
    Maybe someone with more experience about cross() function can comment on this solution.

Children
No Data

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.