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comparison of two design points in a variable sweep

FormerMember
FormerMember

Hi, 

I would like to compare results of two points in a variable sweep from the same run in ADE-XL. The spec comparison feature in ADE-XL lets me compare design points from two different history items or two different tests from same history item. But it does not let me select two design points from the same run. The 'Point' tab in comparison mode dialog box does not change when I try to select two different design points in the same run. 

For example, I am running a dc sweep for 3 design points with temperature as a variable. Temp = 10 20 30. Let's say I want to get the difference in dc current between points 0 and 1 and points 1 and 2. The spec comparison feature allows me to select

Reference= Interactive.11 Test=1, point =1

Reference= Interactive.10 Test=1, point =1

But the comparison setup does not allow me to select

Reference= Interactive.10 Test=1, point =1 

Reference= Interactive.10 Test=1, point =2 

Is there any issue with this feature?

Also, is there a way I can write an expression for this using an ocean script where I would get difference between results of two consecutive design points in a variable sweep?

Thanks in advance. 

Parents
  • Andrew Beckett

    If you're doing a dc sweep (i.e. within the analysis), the spec comparison tool can't be used for that. The sweep would need to be done as a sweep of a global variable in ADE or over corners - that's what generates "points" - each set of results in the ADE output pane.

    What does your simulation setup look like? What do you see in the ADE Results panel?

    Andrew

  • FormerMember
    FormerMember in reply to Andrew Beckett

    Hi Andrew, 

    Thank you for the reply. As you mentioned, I was doing variable sweep in corners setup, which did not generate design points. When I moved the sweep in global variables, I am able to generate design points. 

    For example, if I want to measure current in a resistor against the voltage sweep and check the linearity between two consecutive design points. 

    Here I am able to see %Error between points 2 and 3. It is possible to codify this %Error across a range of points, such as points 3 and 4, 4 and 5 and so on. Is there any such feature in ADEXL or can I do it using ocean script? If yes, what would be the SKILL command to bring out %Error, or the design point as a variable?

    Thanks,

    Vishal

Reply
  • FormerMember
    FormerMember in reply to Andrew Beckett

    Hi Andrew, 

    Thank you for the reply. As you mentioned, I was doing variable sweep in corners setup, which did not generate design points. When I moved the sweep in global variables, I am able to generate design points. 

    For example, if I want to measure current in a resistor against the voltage sweep and check the linearity between two consecutive design points. 

    Here I am able to see %Error between points 2 and 3. It is possible to codify this %Error across a range of points, such as points 3 and 4, 4 and 5 and so on. Is there any such feature in ADEXL or can I do it using ocean script? If yes, what would be the SKILL command to bring out %Error, or the design point as a variable?

    Thanks,

    Vishal

Children
  • Andrew Beckett
    in reply to FormerMember

    Hi Vishal,

    You can't really do this with the compare specs UI because that's not what it's for. You could probably use a "measurement across sweeps" or similar (in ADE Assembler) to check (say) the derivative of a measurement across the swept variable. ADE XL only had "measurement across corners" (setting the EvalType column to "corners") whereas ADE Assembler can also take a measurement across sweeps or all - the idea is that you can then do some computation across the entire set of data (or just the sweeps or just across the corners) rather than the normal measurements which are per-simulation.

    Andrew

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