How to sample a signal at specific (non-uniform) points in time?

See this article: Calculator function to measure the value of a waveform when another waveform crosses a threshold

Andrew

Thanks!

Quick follow-up question:

Calling abCrossTwoWaves seems to work inside the calculator, but not when set as output in ADE Explorer or ADE Assembler. What to do such that this works as well?

Dear DomiHammerfall,

DomiHammerfall said:

Calling abCrossTwoWaves seems to work inside the calculator, but not when set as output in ADE Explorer or ADE Assembler. What to do such that this works as well?

1. Are you using the SKILL function in a post-simulation ocean script defined as an output?

If so,at the beginning of all my ocean scripts, I load the functions I need for the script. As an example, the initial lines for a script that calls a couple of user defined scripts integrate() and rise_fall():

load("/home/smlogan/ocean_files/integrate.il")
load("/home/smlogan/ocean_files/rise_fall.il"

....

Hence, in your case, include the line:

load("<path_to_script>/abCrossTwoWaves.il")

at the beginning of your ocean script.

2. If you using the script name as part of an ADE output expression, did you try including the load statement:

load("<path_to_script>/abCrossTwoWaves.il")

in your .cdsinit (and then restarting Virtuouso) or instantiating the load command in the CIW?

Shawn

ShawnLogan said:

2. If you using the script name as part of an ADE output expression, did you try including the load statement:

load("<path_to_script>/abCrossTwoWaves.il")

in your .cdsinit

If you use the approach in the article and use the "fx" button in the calculator (or + button in the expression builder) to add the function, then there is no need to load it in the .cdsinit (and/or .vdsinit). It will get loaded automatically by the calculator (because the code contains functions to register with the calculator).

However, the additional file (your original reply mentioned this, but you've edited it since) abMakeWaveform.il will not get auto-loaded (that's not a calculator function so isn't really suitable for registration this way). For that, you should add the line:

load("/path/to/abMakeWaveform.il") 

to both your .cdsinit and also .vdsinit (the .vdsinit if it doesn't exist can be in various places, but most likely your working directory or failing that the home directory). The .vdsinit file is used for the expression evaluator as part of the LSCS mechanism in ADE; if using the calculator or the older ICRP mechanism, then the .cdsinit is needed.

That should then allow it to work in the calculator and output expressions.

ShawnLogan said:

1. Are you using the SKILL function in a post-simulation ocean script defined as an output?

If so,at the beginning of all my ocean scripts, I load the functions I need for the script.

I wouldn't recommend this approach. For a start, the code ends up potentially being loaded multiple times unnecessarily, and it's far cleaner to load calculator functions by the registration mechanism or to load common utilities through the .cdsinit/.vdsinit file.

Andrew

Thanks for the help Shawn and Andrew.

I added the .il file both in .cdsinit and .vdsinit. So my .cdsinit file looks like this:

envSetVal("maestro.lscs" "centralizedDotVdsinitDirectory" 'string "/path/to/.vdsinit")
load("/path/to/abCrossTwoWaves.il")
load("/path/to/abMakeWaveform.il")

The first line is taken from here. The .vdsinit file looks as follows:

load("/path/to/abCrossTwoWaves.il")
load("/path/to/abMakeWaveform.il")

The CDS.log does not show any errors on startup.
The behaviour I observe in Virtuoso is very strange, though. I set

abCrossTwoWaves(VT("/vout") VT("/vin") (VAR("vdd") / 2) "rising")

as output in ADE Explorer. After simulation, it just shows "eval err" in the UI. However, if I rightclick and select "send to calculator", then pressing the evaluate button in the calculator gives the correct result.

Thanks for the help Shawn and Andrew.

I added the .il file both in .cdsinit and .vdsinit. So my .cdsinit file looks like this:

envSetVal("maestro.lscs" "centralizedDotVdsinitDirectory" 'string "/path/to/.vdsinit")
load("/path/to/abCrossTwoWaves.il")
load("/path/to/abMakeWaveform.il")

The first line is taken from here. The .vdsinit file looks as follows:

load("/path/to/abCrossTwoWaves.il")
load("/path/to/abMakeWaveform.il")

The CDS.log does not show any errors on startup.
The behaviour I observe in Virtuoso is very strange, though. I set

abCrossTwoWaves(VT("/vout") VT("/vin") (VAR("vdd") / 2) "rising")

as output in ADE Explorer. After simulation, it just shows "eval err" in the UI. However, if I rightclick and select "send to calculator", then pressing the evaluate button in the calculator gives the correct result.

The article you reference is a bit misleading. It was trying to say that centralizedDotVdsinitDirectory should be set to the directory containing .vdsinit - but the example makes it look as if it's the path to the .vdsinit itself (which it is not). So you should set:

envSetVal("maestro.lscs" "centralizedDotVdsinitDirectory" 'string "/path/to") ; i.e. not the file but the containing directory

That should work if you do that. As I said, this is less important for abCrossTwoWaves.il if properly registered, but for the abMakeWaveform.il you certainly need to use this approach (or have a local .vdsinit).

Andrew

Thanks for your reply.

I can confirm that it is working correctly now.