PlaceAndConnect

class picazzo3.routing.place_route.cell.PlaceAndConnect(*args, **kwargs)

Parametric Cell for manual placement and Logical connection of components.

The user supplies a dictionary of the instances of child cells that need to be placed through the property child_cells. This dictionary maps the instance names to the PCell objects. The same PCell object can be used for multiple instances.

child_cells={ "ring1"  : my_ring1,
              "ring2"  : my_ring2,
              "spl"    : my_splitter,
              "com"    : my_splitter # the same cell is used both for splitting and combining
              }

The connectivity between the instances of the child cells is set by a list of tuples containing pairs of instance terms/port names. This list links is of the form instname:portname

links=[ ("spl:arm1",   "arm1:in1"),
        ("arm1:out1", "com:arm1"),
        ("spl:arm2",   "arm2:in1"),
        ("arm2:out1", "com:arm2")
        ]

All the unused terms of the instances are connected to outside terms. You can override the default external term names using the external_port_names property. There you can specify the individual names of the external terms. If no name is specified, the default pattern of ‘instname_termname’ will be used.

external_port_names={ "spl:in1"  : "input",
                      "com:out1" : "output"
                      }

The PCell will place the waveguides and connect them logically in the netlist, but it is up to the user to verify whether the physical location of the connected ports matches.

In the layout, the placement is specified manually using the child_transformations property, which defines a transformation for each instance. If no transformation if supplied for an instance, no transformation will be applied. It is also possible to supply a coordinate (Coord2) or tuple, which will be interpreted as a position for placement.

child_transformations={"arm1": (50, -50),
                       "arm2": (50,50),
                       "com": i3.HMirror(0.0)+i3.Translation((100,0))}

Child cells that are logically connected but where the ports are not physically connected (e.g. by wrong placement), will be connected with visual flylines.

You can subclass this PCell in order to implement your own additional functionality, or define subcircuits that define their own child cells and child transformations. Warning: do not refer to self.child_cells from within an overridden _default_child_transformations - rather refer to the child cell directly (like self.my_child_cell).

Parameters:

child_cells: optional

dict to create the instances of the child cells. Format is {‘inst_name1’: PCell}

links: list and List with type restriction, allowed types: [<class ‘_abcoll.Sequence’>], optional

list of tuples connecting the instances. Format is [(‘inst1:term1’,’inst2:term2’), …]

external_port_names: optional

Map of the free instance terms/ports to the names of external terms/ports.Format is a dict {‘inst:term’ : ‘new_term_name’}.If a term/port is not listed, the format instname_portname will be used

cell_instances: _PCellInstanceDict, optional

name: optional

The unique name of the pcell

Views

Layout
Parameters:

flyline_layer: optional

layer to draw flylines of physically unconnected links

flyline_width: float and number > 0, optional

line width of the flylines

view_name: str, optional

The name of the view

child_transformations: optional

dictionary with the transformation of each child instance.

netlist_view: NetlistView, optional

Netlist view in the same cell on which this Layout is based. Normally no need to manually override.

grids_per_unit: locked

Number of grid cells per design unit

units_per_grid: locked

Ratio of grid cell and design unit

grid: float and number > 0, locked

design grid. Extracted by default from TECH.METRICS.GRID

unit: float and number > 0, locked

design unit. Extracted by default from TECH.METRICS.UNIT

Examples

""" Here we connect together 2 splitters and two rings to form a Ring-loaded
    Mach-Zehnder. We use the splitter twice (as splitter and combiner) but use
    two different rings. We calculate the transformations of the rings in such
    a way that the attach correctly to the splitter and combiner
    """
from technologies import silicon_photonics
from ipkiss3 import all as i3

from picazzo3.filters.ring import RingRect180DropFilter, RingRectNotchFilter
from picazzo3.wg.splitters import WgY180Splitter

from picazzo3.routing.place_route import PlaceAndConnect

from ipkiss.geometry.vector import vector_match_transform

# both rings have the same size
ring1 = RingRectNotchFilter()
ring1_layout = ring1.Layout()
ring2 = RingRect180DropFilter()
ring2_layout = ring2.Layout()
splitter = WgY180Splitter()
splitter_layout = splitter.Layout()

pr = PlaceAndConnect(child_cells={"spl": splitter,
                                  "com": splitter,
                                  "arm1": ring1,
                                  "arm2": ring2},
                     links=[("spl:arm1", "arm1:in"),
                            ("arm1:out", "com:arm1"),
                            ("spl:arm2", "arm2:in1"),
                            ("arm2:out1", "com:arm2")]
                     )

# manually calculate the transformations needed to attach the ports together
t_ring1 = vector_match_transform(ring1_layout.ports["in"], splitter_layout.ports['arm1'])
t_ring2 = vector_match_transform(ring2_layout.ports["in1"], splitter_layout.ports['arm2'])
t_com = vector_match_transform(splitter_layout.ports['arm1'], ring1_layout.ports['out'], mirrored=True) + t_ring1

layout = pr.Layout(child_transformations={"arm1": t_ring1,
                                          "arm2": t_ring2,
                                          "com": t_com}
                   )
layout.visualize()
../../../../_images/picazzo3-routing-place_route-cell-PlaceAndConnect-1.png