Coverage for klayout_pex/klayout/netlist_reducer.py: 96%

1# 

2# -------------------------------------------------------------------------------- 

3# SPDX-FileCopyrightText: 2024-2025 Martin Jan Köhler and Harald Pretl 

4# Johannes Kepler University, Institute for Integrated Circuits. 

5# 

6# This file is part of KPEX  

7# (see https://github.com/iic-jku/klayout-pex). 

8# 

9# This program is free software: you can redistribute it and/or modify 

10# it under the terms of the GNU General Public License as published by 

11# the Free Software Foundation, either version 3 of the License, or 

12# (at your option) any later version. 

13# 

14# This program is distributed in the hope that it will be useful, 

15# but WITHOUT ANY WARRANTY; without even the implied warranty of 

16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

17# GNU General Public License for more details. 

18# 

19# You should have received a copy of the GNU General Public License 

20# along with this program. If not, see <http://www.gnu.org/licenses/>. 

21# SPDX-License-Identifier: GPL-3.0-or-later 

22# -------------------------------------------------------------------------------- 

23# 

24from typing import * 

25 

26import klayout.db as kdb 

27 

28from ..log import ( 

29 info, 

30) 

31from .parasitic_device_classes import PARASITIC_CAPACITOR_CLASS_NAME 

32 

33 

34class NetlistReducer: 

35 @staticmethod 

36 def reduce(netlist: kdb.Netlist, 

37 top_cell_name: str, 

38 cap_threshold: float = 0.05e-15) -> kdb.Netlist: 

39 reduced_netlist: kdb.Netlist = netlist.dup() 

40 reduced_netlist.combine_devices() # merge C/R 

41 

42 top_circuit: kdb.Circuit = reduced_netlist.circuit_by_name(top_cell_name) 

43 

44 devices_to_remove: List[kdb.Device] = [] 

45 

46 for d in top_circuit.each_device(): 

47 d: kdb.Device 

48 dc = d.device_class() 

49 # NOTE: only the parasitics KPEX added, the capacitors of the LVS netlist (e.g. MIM, MOM) 

50 # may have no C parameter (#203) 

51 if dc.name == PARASITIC_CAPACITOR_CLASS_NAME: 

52 # net_a = d.net_for_terminal('A') 

53 # net_b = d.net_for_terminal('B') 

54 c_value = d.parameter('C') 

55 if c_value < cap_threshold: 

56 devices_to_remove.append(d) 

57 

58 elif isinstance(dc, kdb.DeviceClassResistor): 

59 # TODO 

60 pass 

61 

62 for d in devices_to_remove: 

63 info(f"Removed device {d.name} {d.parameter('C')}") 

64 top_circuit.remove_device(d) 

65 

66 return reduced_netlist