Measurement of Static Noise Margin(SNM) for SRAM

[samvelc]

Hi All,

I have some questions regarding measurement of SNM for SRAM (6T).

Please see attached file.
First, I have applied ramped signal to two inverters and got output signals (v(out1) & v(out2)).
After that I have swapped X & Y coordinates for v(out1) signal and got the green curve (swapXY(v(out1)).

Does butterfly curve perform with v(out1) and swapXY(v(out1)) signals????

Schematic Designers, please advice.

Thanks in advance.

 

[dameash]

could you help me with how to do the butterfly curves please