Stats

  • Locked Locked
  • Replies 17
  • Subscribers 144
  • Views 19136
  • 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 to automatically store technology version on instance in schematics and layout?

Sheppy

Hi,

I'd like to store the version number of the PDK on an instance when this instance is instantiated in schematic or layout. I need this in order to be able to check with which version of the PDK a particular design has been made. Later, I will create a script that hierarchically checks all instances of a given design, and reports the used versions. This will then be a script run at tape-out to ensure all devices are generated with the correct (latest) PDK version.

It could be done by adding a parameter with the version number as value to the CDF, like this:

cdfCreateParam( cdfId
        ?name           "PDK_version"
        ?prompt         "PDK Version"
        ?defValue       "x.y.z"
        ?type           "string"
        ?display        "t"
        ?editable       "nil"
        ?storeDefault   "yes"
)

However, if the PDK gets updated, the version number will be increased, which would mean, with this implementation, that the CDF of all cells in the library have to be updated to the new version. Of course, this could be automated, but i would like to use a different approach.

The version of the PDK which is loaded in Virtuoso is stored in an environment variable called TECH_VERSION. It can be retrieved by doing:

getShellEnvVar( "TECH_VERSION" )

What I would like to happen is that when the instance is instantiated, the value of TECH_VERSION is automatically stored in the CDF parameter PDK_version. Something like this doesn't work:

cdfCreateParam( cdfId
        ?name           "PDK_version"
        ?prompt         "PDK Version"
        ?defValue       "getShellEnvVar( \"TECH_VERSION\" )"
        ?type           "string"
        ?display        "t"
        ?editable       "nil"
        ?storeDefault   "yes"
)

This would simply put the text "getShellEnvVar( "TECH_VERSION" )" as value in the "PDK_version" field.

An other solution could be by putting some code in a call-back procedure that puts the version number in the parameter value. However, this only works when this call-back procedure is triggered. If a default device is instantiated, with no modifications to its parameters, the call-back will not be triggered, thus the version number will not be set.

So, I think this has to be a post-instantiation trigger. And I don't know how to do that properly. Any help is highly appreciated.

If an other solution is possible, I would surely like to know that as well.

Thanks in advance.

With kind regards,

Sjoerd

Parents

  • Hi Andrew,

    Thank you for this solution, it does exactly what I want.

    Now I have only one more thing to get working too: when an instance is created using a script, by using the dbCreateParamInst(), I want to automatically store the PDK version as well. I tried to register a trigger like Yi suggested, but that doesn't work. There is not a valid trigger for creating an instance using the dbCreateParamInst() function.

    What I have done now is adding a bit of code to the callback procedure that handles all parameter input. When after the creation of an instance the CCSinvokeInstCdfCallbacks() is called, it will look in the stack to see whether or not it was called from that procedure and then updates the PDK version parameter. This works, but if run on an old cellview, it will update the PDK version parameter on old instances as well. So far I haven't found a solution to get around this. What I think I need is a trigger after an instance is created.

    With kind regards,

    Sjoerd Herder

Reply

  • Hi Andrew,

    Thank you for this solution, it does exactly what I want.

    Now I have only one more thing to get working too: when an instance is created using a script, by using the dbCreateParamInst(), I want to automatically store the PDK version as well. I tried to register a trigger like Yi suggested, but that doesn't work. There is not a valid trigger for creating an instance using the dbCreateParamInst() function.

    What I have done now is adding a bit of code to the callback procedure that handles all parameter input. When after the creation of an instance the CCSinvokeInstCdfCallbacks() is called, it will look in the stack to see whether or not it was called from that procedure and then updates the PDK version parameter. This works, but if run on an old cellview, it will update the PDK version parameter on old instances as well. So far I haven't found a solution to get around this. What I think I need is a trigger after an instance is created.

    With kind regards,

    Sjoerd Herder

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.