Is There a Workaround for the Case of a PDK Not Supporting Split Resistor Import Correctly?

Never had a problem with TSMC, but UMC was always a nightmare, as Sunny of Qorvo might attest.

Thankfully, Sandeep's SKILL coding skills came to the rescue.

Get this file here.

You select all the newly imported resistors, do CTRL-M to go back into grouped mode, and then fire the weapon.

Problem : in the PDK I was in, import in split mode brought each segment in with W/N (N = number of stripes). In addition, a common problem in most PDKs is that segments brought in in split mode (that is, when the series-factors setting was set to include the variable (in the CDF for the primitive) that refers to (in this case, stripes, or segments - "ser")) are not linked to the schematic instance (cross-selection not working) when user returns to parallel mode (CTRL-M if you have this script).


You will see that the R value hasn't been updated. That led to 46926230:

As the video shows, the R value is still incorrect. 

Is there a simple workaround for this? Some command we can run to update this component - maybe by running the PDK callback on it to update R based on W and L?

Ans: Yes, get the files. And then:

Load the code via the CIW:

load("CCSinvokeCdfCallbacks.il")

Open the schematic on which you want to run the code, and then call:

CCSinvokeCdfCallbacks(geGetEditCellView())

Comments

Post a Comment

Popular posts from this blog

Plotting Device Parameters (gm, vdsat, etc) Vs Time or Temp

Image
I feel like this has gotten more complicated. I think it might have been easier 10 years ago. Then again, I could be w. Go to resource: How to save and plot operating point parameters for Spectre simulator from ADE Explorer/Assembler In Explorer, you go to Outputs > To be Saved > Select OP Parameters Now, the schematic window is active and you can click on instances and each gets highlighted as you do. These get populated in the Assembler Outputs Setup You will see that the "Type" is not signal but oppoint. If you click on the Details field, it splits into two - the /whatever/deviceName is on the left, and on the new field on the right, you can enter parameters appropriate for that device, like vdsat, vth, cgs, etc.  The UI is very poor, but, on the right of this field is a button you can actually click to choose from a list. It'll even run a sim if necessary! If you want these plotted, you have to check the box to the right under the Plot column.
Read more

When You Want to Get Cycle-to-Cycle Jitter at PLL Output Due to the Reference Oscillator

Image
Caution - the script does not provide the correct result. You expect cycle-to-cycle to be a high-frequency phenomenon - and therefore, to not depend on the oscillator phase-noise or jitter. But the script will show a large value for c2c jitter on the PLL output. If you can figure it out, please post/comment. Designers Guide : Phase Noise and Jitter prediction , by Ken Kundert Converting Phase Noise to Cycle-to-Cycle Jitter in a PLL When designing or analyzing phase-locked loops (PLLs), one key metric of interest is the RMS cycle-to-cycle jitter at the output. Given phase noise data (typically in dBc/Hz) for the reference oscillator, how do we estimate the jitter after the PLL processes it? 🎯 Goal Estimate RMS cycle-to-cycle jitter (in seconds or picoseconds) at the output of a PLL , based on: Measured or simulated phase noise data (dBc/Hz vs. offset frequency) PLL dynamics: natural frequency ( fn ), damping ratio ( ζ ), divider ratio ( N ) Carrier frequency ( fc ) ...
Read more

HIdden States in Your Behavioral Model

Image
Rewrite the module to remove the hidden state or if you confirm this hidden state will not affect the simulation result, you can ignore those hidden states in RF analysis by adding attribute 'ignore_hidden_state' before the module declaration. For example,  (* ignore_hidden_state *) module moduleA Yes, that's the exact syntax you need to use - that line works so much magic. It's strange that Cadence would offer behavioral models to customers in its ahdlLib library that aren't "ready to roll" in terms of NOT having hidden states. https://designers-guide.org/analysis/PLLnoise+jitter.pdf https://community.cadence.com/cadence_technology_forums/f/rf-design/26712/how-to-avoid-hidden-state-in-veriloga-model-for-spectrerf
Read more