# Copyright 2013 Devsim LLC

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

import sys

import devsim as ds

from .simple_physics import *

def rampbias(device, contact, end_bias, step_size, min_step, max_iter, rel_error, abs_error, callback):

'''

Ramps bias with assignable callback function

'''

start_bias = ds.get_parameter(device=device, name=GetContactBiasName(contact))

if (start_bias < end_bias):

step_sign=1

else:

step_sign=-1

step_size=abs(step_size)

last_bias=start_bias

while(abs(last_bias - end_bias) > min_step):

print(("%s last end %e %e") % (contact, last_bias, end_bias))

next_bias=last_bias + step_sign * step_size

if next_bias < end_bias:

next_step_sign=1

else:

next_step_sign=-1

if next_step_sign != step_sign:

next_bias=end_bias

print("setting to last bias %e" % (end_bias))

print("setting next bias %e" % (next_bias))

ds.set_parameter(device=device, name=GetContactBiasName(contact), value=next_bias)

try:

ds.solve(type="dc", absolute_error=abs_error, relative_error=rel_error, maximum_iterations=max_iter)

except ds.error as msg:

if str(msg).find("Convergence failure") != 0:

raise

ds.set_parameter(device=device, name=GetContactBiasName(contact), value=last_bias)

step_size *= 0.5

print("setting new step size %e" % (step_size))

if step_size < min_step:

raise RuntimeError("Minimum step size too small")

continue

print("Succeeded")

last_bias=next_bias

callback(device)

def printAllCurrents(device):

'''

Prints all contact currents on device

'''

for c in ds.get_contact_list(device=device):

PrintCurrents(device, c)