# SPDX-License-Identifier: Apache-2.0
# Copyright 2019 Blue Cheetah Analog Design Inc.
#
# 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.
from typing import Dict, Any
import pkg_resources
from pathlib import Path
from pybag.enum import TermType
from bag.design.module import Module
from bag.design.database import ModuleDB
from bag.util.immutable import Param
# noinspection PyPep8Naming
[docs]class xbase__nmos4_stack(Module):
"""Module for library xbase cell nmos4_stack.
Fill in high level description here.
"""
[docs] yaml_file = pkg_resources.resource_filename(__name__,
str(Path('netlist_info',
'nmos4_stack.yaml')))
def __init__(self, database: ModuleDB, params: Param, **kwargs: Any) -> None:
Module.__init__(self, self.yaml_file, database, params, **kwargs)
@classmethod
[docs] def get_params_info(cls) -> Dict[str, str]:
return dict(
w='width of the transistor, in resolution units or fins.',
lch='channel length, in resolution units.',
seg='number of segments.',
intent='threshold flavor.',
stack='number of transistors in a stack.',
export_mid='True to export intermediate node.',
)
@classmethod
[docs] def get_default_param_values(cls) -> Dict[str, Any]:
return dict(
stack=2,
export_mid=False,
)
[docs] def get_master_basename(self) -> str:
w = self.params['w']
l = self.params['lch']
seg = self.params['seg']
intent = self.params['intent']
stack = self.params['stack']
# choose 3 terminal mos without extra parameter by encoding it in the intent
# e.g.: 3_standard
if intent.startswith('4_'):
# Case 1: 4 terminal mos
mos_type = f'nmos{intent}'
elif intent.startswith('3_'):
# Case 2: changing to 3 terminal mos
mos_type = f'nmos{intent}'
else:
# Case 3: default case
mos_type = f'nmos4_{intent}'
if stack > 1:
ans = f'{mos_type}_stack{stack}_w{w}_l{l}_seg{seg}'
else:
ans = f'{mos_type}_w{w}_l{l}_seg{seg}'
return ans
[docs] def design(self, w: int, lch: int, seg: int, intent: str, stack: int, export_mid: bool) -> None:
if stack < 1:
raise ValueError(f'stack = {stack} must be >= 1.')
if stack != 2:
if stack > 1:
self.rename_pin('g<1:0>', f'g<{stack - 1}:0>')
gate = [f'g<{idx}>' for idx in range(stack)]
else:
self.rename_pin('g<1:0>', 'g')
gate = 'g'
else:
if export_mid:
if seg == 1:
self.add_pin('m', TermType.inout)
else:
self.add_pin(f'm<{seg-1}:0>', TermType.inout)
gate = ['g<0>', 'g<1>']
self.design_transistor('XN', w, lch, seg, intent, g=gate, m='m', stack=stack)
if intent.startswith('3_'):
self.remove_pin('b')