# Layout Reference¶

The Layout of a PCell represents the physical implementation of your design. This means it’s made of a set of geometrical elements that belong to a certain layer. It’s also possible to add additional information like port and device labels.

All layout information of your PCell is captured in the LayoutView. Typically the structure of a PCell with a LayoutView will look as follows:

import ipkiss3.all as i3
class MyCell(i3.PCell):
class Layout(i3.LayoutView):
# some layout specific properties
length = i3.PositiveNumberProperty(default=10, doc="length")
width = i3.PositiveNumberProperty(default=2, doc="some width")

def _generate_instances(self, insts):
# In _generate_instances, we'll specify the
# references to child layouts

def _generate_elements(self, elems):
# in _generate_elements Geometrical Elements

def _generate_ports(self, ports):
# Used to specify the input & output of your component


Separating the definition of all components of a LayoutView helps to assure that your LayoutView is well structured.

The Layouting capabilities in IPKISS are quite extensive, which is why the reference manual is split into different themes below. For a condensed guide about layout you can visit the layout guide.

Elements, Layers & Instances
Elements are the basic building blocks of the layout. These can be geometric data drawn on a certain layer, or instances to other PCells for building hierarchical layouts.
Shapes & Geometry
All layoutviews are in the end composed of a set of the geometrical primitives. Use this part of the reference to find out how to build the geometry of your layout.

Generated Layers

Ports
Ports are locations on the layout where connections are made.
Placement
Functions for placing PCells according to a predefined set of constraints.
Routing
Creates a path from one point to another, this path can then be used to create a waveguide or another type of trace.
Transformations
Predefined transformations in IPKISS used to transform (i.e., rotate, translate) layout instances and geometrical primitives.
Importing from GDSII
If you have existing GDSII layouts it is possible to import them into IPKISS.
IoColumn
Used to place components on top of each other and connect them to grating or edge couplers on the side.
Shape modifiers
Predefined shape modifiers for modifying existing shapes.