Using a file for vpwlf source

Hi Huan Nguyen

You can do it as follows:
a. Place an instance of "vsource" from "analogLib" in your schematic
b. Set the "source type" to "pwl"
c. Specify the path to your viva file in the properties form


Best regards
Quek

Thank you. I've just tried that and there is an error something like this "Unexpected numeric value 0" in the file. What is the format and extension of the file? I tried scsv, csv, txt but none of them works. About the format I tried as below:

0 1

1 2

2 3

There is a space between two numbers in each row. But that also didn't work. Hope you could figure out something wrong here.

Hi Huan Nguyen

PWL is a 2 column, time-value format. Your input is correct and should work. The file extension does not matter. Would you please provide a snapshot of the vsource properties form?

Best regards
Quek

Thank you very much for the help and sorry for the late reply.

I am not at school right now so I can not post the picture. I use PWL source a lot and it works perfectly if I input the values manually. However, I couldn't make it work with a file.

For a file, I tried to do it as follows:

1. Create a file with csv or txt extension such as stimulus.csv or stimulus.txt.

2. Refer it by ADE --> Model Libraries and set the path of the file.

3. From schematic, pick vsource and choose PWL type.

In File section, type the name of the file (stimulus.csv or stimulus.txt)

When I run the simulation, there is an error something like error numeric value. I will post it once I get to school.

For the file, the content is something like this:

0 1 

1 2

2 3

The first column is time and the second column is value. They are separated by a space.

OK  - the problem is that you're referring to it via ADE->Model Libraries. That's wrong - this is NOT a model file, and so what it would be trying to do is read that file as a SPICE netlist (assuming those suffixes). All you need to do is specify the name of the file on the source itself. 

You can either specify the full path to the file, or better just put "stimulus.txt" and then in ADE->Setup->Simulation Files specify the Include Path to include the directory which contains the stimulus.txt file. In other words, non-fully-qualified path names get resolved using the include path in spectre.

Regards,

Andrew.

Thank you, Andrew.

You are right. It works like a charm now!

Hi Andrew Beckett,

I want to use a noisy signal as an input to my circuit in cadence, and I took the following steps:-

1. I created a CSV format file of the noisy signal generated from matlab.
2. In cadence, I went to ADE -> Setup -> Simulation files, and in the "include Paths", I included the path of that CSV file.
3. Then I used a ipwlf source in my schematic, and in its properties I mentioned the CSV file name in "PWL file name", and also mentioned the period of that noisy signal in "Period of the PWL".

after doing all these steps, I am not able to plot the waveform in cadence. 

In that CSV file, there are two columns , first column is representing time axis and the second one represents the amplitudes of the noise signal.

What might be the possible reason for this?

First of all, please read the Guidelines for the Custom IC Design Forum. They ask you not to post in old threads (by all means create a new post and then link to an old thread so that there's a reference).

Did spectre give an error? Did you give the directory containing the file in the include path, or the whole path the file? (it needs to be the directory). Can you give an example of the CSV file plus how you set it up on the voltage source? Is the stop time of the simulation long enough to see the changes? Which version of Spectre are you running? (this probably doesn't matter too much, but it's good practice to provide this).

Andrew