Labs/Lab2/process.py

import os
import ltspice
import matplotlib.pyplot as plt
import numpy as np

simulations = {
  "longchannel": (5.0, """
    .include modelcard/1um.pm
    .param supply = {}
    .param ll = 1u
  """),
  "50nm": (1.0, """
    .include ./modelcard/50nm.pm
    .param supply = {}
    .param ll=50nm
  """),
  "16nmlp": (0.9, """
    .include ./modelcard/PTM_LP/16nm.pm
    .param supply = {}
    .param ll=16nm
  """),
  "16nmhp": (0.7, """
    .include ./modelcard/PTM_HP/16nm.pm
    .param supply = {}
    .param ll=16nm
  """)
}

moss = {
  "nmos": "M1 2 1   0   0 nmos W={10*ll} L= ll",
  "pmos": "M1 2 1 vdd vdd pmos W={10*ll} L={ll}"
}

script_dc = """
  vdd vdd 0 {supply}
  Vgs 1 0   {supply}
  Vds 2 0   {supply}
  .op
  .dc vds 0 {supply} {supply/100} Vgs 0 {supply} {supply/12}
  *.step param lambda 50n 100n 10n
  .meas ix(1:D) at vgs='supply'
  .save I(vds)
  .end
"""

script_ring = """
.subckt nn d g s  ww=100nm
mnfet d g s gnd nmos L=ll w=ww
.ends

.subckt pp d g s   ww=100nm
mpfet d g s vdd pmos L=ll w=ww
.ends


.subckt inv out inn size=100n beta=2
XPP out inn vdd pp ww='size*beta/(beta+1)'
XNN out inn 0   nn ww='size/(beta+1)'
.ENDS inv

.global gnd vdd
vdd vdd 0 'supply'
*Top level
.ic v(n0)=0
X0 n1 n0 inv size = '10*ll'
X1 n2 n1 inv size = '10*ll'
X2 n3 n2 inv size = '10*ll'
X3 n4 n3 inv size = '10*ll'
X4 n0 n4 inv size = '10*ll'
.tran 0.1p 3n
"""

def find_period(ident, script, model, mos, l):
    time = l.get_time()
    data = l.get_data('V(n0)')
    largest = max(data)
    smallest = min(data)
    diff = largest-smallest
    nearmax = [(i, dp) for (i, dp) in enumerate(data) if abs((largest-dp)/diff) < 0.01]
    nearmin = [(i, dp) for (i, dp) in enumerate(data) if abs((smallest-dp)/diff) < 0.01]

    group1, group2 = [], []
    # Discard near-min values
    while nearmin[0][0] < nearmax[0][0]:
        nearmin.pop(0)
    # Group first peak
    while nearmax[0][0] < nearmin[0][0]:
        i, dp = nearmax.pop(0)
        group1.append((dp, time[i]))
    # Discard near-min values
    while nearmin[0][0] < nearmax[0][0]:
        nearmin.pop(0)
    # Group first peak
    while nearmax[0][0] < nearmin[0][0]:
        i, dp = nearmax.pop(0)
        group2.append((dp, time[i]))
    peak1 = max(group1)[1] * 1000000000000
    peak2 = max(group2)[1] * 1000000000000
    print(ident, peak2-peak1)

def find_onoff(ident, script, model, mos, l):
    vds = l.get_data('vds')
    current_lo = l.get_data('I(vds)', 0)
    current_hi = l.get_data('I(vds)', l.case_count - 1)
    print(ident, current_lo[-5], current_hi[-5])

def find_gm(ident, script, model, mos, l):
    vds = l.get_data('vds')
    gms = []
    for i in range(l.case_count):
        if i == 0: continue
        max_diff = max(
                [ abs(curr - prev) for (curr, prev) in
                    zip(l.get_data('I(vds)', i), l.get_data('I(vds)', i-1)) ])
        gms.append(max_diff/(simulations[model][0]/12))
    print(ident, max(gms) * 10000)

def render_current(ident, script, model, mos, l):
    vds = l.get_data('vds')
    for i in range(l.case_count):
        curr = l.get_data('I(vds)', i)
        plt.plot(vds, curr)
    plt.savefig(ident + "_current.png", dpi=192)
    plt.close()

def run_sim(script, model, mos, callback):
    scriptname = "t_{}_{}".format(model, mos)
    with open(scriptname + ".cir", "w") as f:
        f.write(simulations[model][1].format(simulations[model][0]))
        if mos is not None: f.write(moss[mos])
        f.write(script)
    if not os.path.exists(scriptname + ".raw"):
        sp = os.popen("wine ~/.wine/drive_c/Program\ Files/LTC/LTspiceXVII/XVIIx64.exe -b {}.cir -ascii"
            .format(scriptname))
        sp.read()
    l = ltspice.Ltspice(scriptname + ".raw")
    l.parse() 

    callback(scriptname, script, model, mos, l)


for mos in moss.keys():
    for node in simulations.keys():
        run_sim(script_dc, node, mos, find_onoff)

for node in simulations.keys():
    run_sim(script_ring, node, None, find_period)