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expression to get a scalar after a sweep

davidzti

Hello,

I found some info on this subject posted a few years ago, but wasn't able to find a definitive solution.  I've been trying to get a scalar output from a sweep and use it in other tests via calcVal function, similar in spirit to these couple posts:

https://community.cadence.com/cadence_technology_forums/f/38/t/30795

https://community.cadence.com/cadence_technology_forums/f/38/t/17712

However, I can't figure out how to do it!  I wanted to ask if this functionality is available (to evaluate expression on a data set, vs on a per-point basis)?  If so, would someone kindly advise on how I can accomplish this?  (I'm on 6.1.6).

Many thanks in advance,

David

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  • davidzti

    Hi Andrew,

    Thank you for the reply.   I'll happily provide some context.

    I have a block the output of which is the signal of interest (e.g., bandgap voltage, Vbg).  The block has 5 trim bits, and for each trim code, I want to sweep the temperature (say -40 to 125), and determine which trim code produces lowest Vbg spread over temp.

    I'm running DC sweep setup in ADEXL (test1), with temperature selected as the sweep variable.  I have setup a "corner" in ADEXL where I increment the trim codes, and for each code I calculate an expression spread, which is defined as (ymax(VS("/Vbg")) - ymin(VS("/Vbg"))).  What I would like to do next is calculate min_spread_code=xmin(spread), and assign calcVal("min_spread_code" "test1") to a variable in another test that's to follow.

    Here's where I run into a problem.  I can place the expression xmin(spread) in the calculator after test1 concludes, and get exactly what I want (the minimum of the array), however, when I include that expression in the test setup and hit "run", it attempts (and fails) to calculate it per point, not on the complete distribution.

    David

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  • davidzti

    Hi Andrew,

    Thank you for the reply.   I'll happily provide some context.

    I have a block the output of which is the signal of interest (e.g., bandgap voltage, Vbg).  The block has 5 trim bits, and for each trim code, I want to sweep the temperature (say -40 to 125), and determine which trim code produces lowest Vbg spread over temp.

    I'm running DC sweep setup in ADEXL (test1), with temperature selected as the sweep variable.  I have setup a "corner" in ADEXL where I increment the trim codes, and for each code I calculate an expression spread, which is defined as (ymax(VS("/Vbg")) - ymin(VS("/Vbg"))).  What I would like to do next is calculate min_spread_code=xmin(spread), and assign calcVal("min_spread_code" "test1") to a variable in another test that's to follow.

    Here's where I run into a problem.  I can place the expression xmin(spread) in the calculator after test1 concludes, and get exactly what I want (the minimum of the array), however, when I include that expression in the test setup and hit "run", it attempts (and fails) to calculate it per point, not on the complete distribution.

    David

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