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Question on OCEAN standalone evaluation

trdastidar

Hi,

Got a question on OCEAN scripts (same applies to artil as well)

I have an ADE L state, from which I save the OCEAN script, and then run it. It runs fine.

Suppose, there is a calculator function in this OCEAN script, which looks like this:

gain_1 = value(dB20(mag(v("/outp" ?result "ac-ac"))) 1)

plot( gain_1 ?expr '( "gain_1" ) )

Now, suppose I want to run the calculator function again (with possibly some modifications). Since the simulation is already run, I remove the entire top part of the OCEAN script, and replace it with a call to openResults, like below:

openResults( "results.psf" ) ; Replace "results.psf" with the actual path of the PSF directory

I run the OCEAN script, but it fails, with the following error:

> WARNING (OCN-6054): The output '/outp' you selected does not exist. Type outputs() to see the list

Now comes the funny part. I change the calculator expression to the following:

gain_1 = value(dB20(mag(v("outp" ?result "ac-ac"))) 1)

That is, I removed the "/" character in the signal name. The script now runs fine!

Could anyone tell me why this happens? I know the workaround for it, but would like to understand why that workaround is necessary at all.

Parents

  • When you refer to a signal name in one of the access functions (e.g. v(), i(), etc), then if the name starts with a "/" it is a name using the schematic namespace. If it doesn't begin with a slash, it is in the netlist namespace. In the schematic namespace, the names have / as the hierarchy delimiter, and will ultimately need to be mapped to whatever name was actually used in the netlist and then saved into the result database. In order to do this mapping, the ADE netlisters save some additional information in the map and amap directories in the netlist directory. This information is then consulted to do the same mapping when somebody wants to access a result signal using the output database. However, for that to work, the results access has to know where the map directories are. This can be done if the simulation is run from OCEAN or ADE, by virtue of a line in the runObjFile which tells it where the "netlistDir" is. In the absence of this, I think it assumes it is in ../netlist. However, if this mapping data is missing, it cannot do the mapping and hence cannot see signals using the source database namespace.

    If you omit the slash, it's always using the netlist name and so that will work regardless of whether the mapping directories are present. However, you do need to then know how any name was mapped - this mapping can happen due to illegal characters, spectre keywords and so on that have been used.

    In your specific example, outp on the schematic ended up as outp in the netlist, so it was relatively straightforward to resolve.

    Regards,

    Andrew. 

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  • When you refer to a signal name in one of the access functions (e.g. v(), i(), etc), then if the name starts with a "/" it is a name using the schematic namespace. If it doesn't begin with a slash, it is in the netlist namespace. In the schematic namespace, the names have / as the hierarchy delimiter, and will ultimately need to be mapped to whatever name was actually used in the netlist and then saved into the result database. In order to do this mapping, the ADE netlisters save some additional information in the map and amap directories in the netlist directory. This information is then consulted to do the same mapping when somebody wants to access a result signal using the output database. However, for that to work, the results access has to know where the map directories are. This can be done if the simulation is run from OCEAN or ADE, by virtue of a line in the runObjFile which tells it where the "netlistDir" is. In the absence of this, I think it assumes it is in ../netlist. However, if this mapping data is missing, it cannot do the mapping and hence cannot see signals using the source database namespace.

    If you omit the slash, it's always using the netlist name and so that will work regardless of whether the mapping directories are present. However, you do need to then know how any name was mapped - this mapping can happen due to illegal characters, spectre keywords and so on that have been used.

    In your specific example, outp on the schematic ended up as outp in the netlist, so it was relatively straightforward to resolve.

    Regards,

    Andrew. 

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