YAML Place and AutoRoute

YAML Place and AutoRoute#

You have two options for working with gdsfactory:

python flow: you define your layout using python functions (Parametric Cells), and connect them with routing functions.
YAML Place and AutoRoute: you define your Component as Place and Route in YAML. From the netlist you can simulate the Component or generate the layout.

The YAML format contains the schematic together with placement information.

YAML is a human readable version of JSON that you can use to define placements and routes

to define a a YAML Component you need to define:

instances: with each instance setting
placements: with X and Y

And optionally:

routes: between instance ports
connections: to connect instance ports to other ports (without routes)
ports: define input and output ports for the top level Component.

gdsfactory VSCode extension has a filewatcher for *.pic.yml files that will show them live in klayout as you edit them.

extension

The extension provides you with useful code snippets and filewatcher extension to see live modifications of *pic.yml or *.py files. Look for the telescope button on the top right of VSCode 🔭. watcher-button

from IPython.display import Code

import gdsfactory as gf

filepath = "yaml_pics/pads.pic.yml"
Code(filepath, language="yaml+jinja")

instances:
  bl:
    component: pad
  tl:
    component: pad
  br:
    component: pad
  tr:
    component: pad

placements:
  tl:
    x: -200
    y: 500

  br:
    x: 400
    y: 400

  tr:
    x: 400
    y: 600

routes:
  electrical:
    settings:
      separation: 20
      cross_section: metal_routing
      allow_width_mismatch: True
    links:
      tl,e3: tr,e1
      bl,e3: br,e1

c = gf.read.from_yaml(filepath)
c

../_images/867e24de100b8e2857c1ac413af4939662c667d869edc89c7be1912961b82f20.png

Lets start by defining the instances and placements section in YAML

Lets place an mmi_long where you can place the o1 port at x=20, y=10

filepath = "yaml_pics/mmis.pic.yml"
Code(filepath, language="yaml+jinja")

instances:
  mmi_long:
    component: mmi1x2
    settings:
      width_mmi: 4.5
      length_mmi: 10
  mmi_short:
    component: mmi1x2
    settings:
      width_mmi: 4.5
      length_mmi: 5
placements:
  mmi_long:
    port: o1
    x: 20
    y: 10
    mirror: False

c = gf.read.from_yaml(filepath)
c.plot()

../_images/170213822a8c9cff8a714a2ce5a12e90716242cab880913942b2dfb5643babc9.png

ports#

You can expose any ports of any instance to the new Component with a ports section in YAML

Lets expose all the ports from mmi_long into the new component.

Ports are exposed as new_port_name: instance_name, port_name

filepath = "yaml_pics/ports_demo.pic.yml"
Code(filepath, language="yaml+jinja")

name: ports_demo

instances:
  mmi_long:
    component: mmi1x2
    settings:
      width_mmi: 4.5
      length_mmi: 5
placements:
  mmi_long:
    port: o1
    x: 20
    y: 10
    mirror: True
ports:
  o3: mmi_long,o3
  o2: mmi_long,o2
  o1: mmi_long,o1

c = gf.read.from_yaml(filepath)
c.plot()

../_images/90184eee78c4b3aad0c6a33f850c460d8c462c7658511283f1fc39de605646e4.png

You can also define a mirror placement using a port

Try mirroring with other ports o2, o3 or with a number as well as with a rotation 90, 180, 270

filepath = "yaml_pics/mirror_demo.pic.yml"
Code(filepath, language="yaml+jinja")

name: mirror_demo
instances:
  mmi_long:
    component: mmi1x2
    settings:
      width_mmi: 4.5
      length_mmi: 5
placements:
  mmi_long:
    x: 0
    y: 0
    mirror: o1
    rotation: 0

c = gf.read.from_yaml(filepath)
c.plot()

../_images/95a231fbc528d49e0ee5adc219ff46c7b41dd064bff8f383d5881ba68ad1c79a.png

connections#

You can connect any two instances by defining a connections section in the YAML file.

it follows the syntax instance_source,port : instance_destination,port

filepath = "yaml_pics/connections_demo.pic.yml"
Code(filepath, language="yaml+jinja")

name: connections_demo
instances:
  b:
    component: bend_circular
  mmi_long:
    component: mmi1x2
    settings:
      width_mmi: 4.5
      length_mmi: 10
  mmi_short:
    component: mmi1x2
    settings:
      width_mmi: 4.5
      length_mmi: 5
placements:
  mmi_short:
    port: o1
    x: 10
    y: 20
connections:
  b,o1: mmi_short,o2
  mmi_long,o1: b,o2
ports:
  o1: mmi_short,o1
  o2: mmi_long,o2
  o3: mmi_long,o3

c = gf.read.from_yaml(filepath)
c.plot()

../_images/459667b232d7cb0f23a35c1749e2ccbff6d6b37b588a53da07dea7cb751a834f.png

Relative port placing

You can also place a component with respect to another instance port

You can also define an x and y offset with dx and dy

filepath = "yaml_pics/relative_port_placing.pic.yml"
Code(filepath, language="yaml+jinja")

name: relative_port_placing
instances:
  mmi_long:
    component: mmi1x2
    settings:
      width_mmi: 4.5
      length_mmi: 10
  mmi_short:
    component: mmi1x2
    settings:
      width_mmi: 4.5
      length_mmi: 5
placements:
  mmi_short:
    port: o1
    x: 0
    y: 0
  mmi_long:
    port: o1
    x: mmi_short,o2
    y: mmi_short,o2
    dx: 10
    dy: -10

c = gf.read.from_yaml(filepath)
c.plot()

../_images/ab00d8585389a6d33a15a0b3677b034031cd49508e36ce1c33239d19d9dfcb94.png

routes#

You can define routes between two instances by defining a routes section in YAML

it follows the syntax

routes:
    route_name:
        links:
            instance_source,port: instance_destination,port
        settings:  # for the route (optional)
            waveguide: strip
            width: 1.2

filepath = "yaml_pics/routes.pic.yml"
Code(filepath, language="yaml+jinja")

name: with_routes
instances:
    mmi_long:
      component: mmi1x2
      settings:
        width_mmi: 4.5
        length_mmi: 10
    mmi_short:
      component: mmi1x2
      settings:
        width_mmi: 4.5
        length_mmi: 5

placements:
    mmi_long:
        x: 100
        y: 100
routes:
    optical:
        links:
            mmi_short,o2: mmi_long,o1
        settings:
            cross_section: strip

c = gf.read.from_yaml(filepath)
c.plot()

../_images/a0a5aebc67674c59d72fbeb5ed134c8589c655c16eac32819a6a69a46e71223e.png

routes with steps#

You can define steps on the route as part of the settings

filepath = "yaml_pics/routes_steps.pic.yml"
Code(filepath, language="yaml+jinja")

instances:
  t:
    component: pad_array
    settings:
      port_orientation: 270
      columns: 3
  b:
    component: pad_array
    settings:
      port_orientation: 90
      columns: 3
  obstacle:
    component: rectangle
    settings:
      size: [200, 200]
      layer: M3

placements:
  t:
    x: -250
    y: 500
  obstacle:
    x: -179
    y: 200
routes:
  route1:
    routing_strategy: route_bundle
    settings:
      cross_section: metal_routing
      steps:
        - dy: 100
          dx: -100
        - dx: 200
        - dy: 100
    links:
      b,e11: t,e11
      b,e12: t,e12

c = gf.read.from_yaml(filepath)
c.plot()

../_images/0bb1501a97e061476282464a480cf4763d83f7199cf115496c760c94ad83b632.png

routes with waypoints#

You can define waypoints along the route as part of the settings

filepath = "yaml_pics/routes_waypoints.pic.yml"
Code(filepath, language="yaml+jinja")

instances:
  t:
    component: pad_array
    settings:
      port_orientation: 270
      columns: 3
  b:
    component: pad_array
    settings:
      port_orientation: 90
      columns: 3

placements:
  t:
    x: -250
    y: 600
routes:
  route1:
    routing_strategy: route_bundle
    settings:
      cross_section: metal_routing
      waypoints:
        - [0, 300]
        - [400, 300]
        - [400, 400]
        - [-250, 400]
    links:
      b,e11: t,e11
      b,e12: t,e12

c = gf.read.from_yaml(filepath)
c.plot()

../_images/e2289326509fbe3424b94984e3ed81bafb5c4b3146c47780f8311d616cdd824b.png

instances, placements, connections, ports, routes#

Lets combine all you learned so far.

You can define the netlist connections of a component by a netlist in YAML format

Note that you define the connections as instance_source.port -> instance_destination.port so the order is important and therefore you can only change the position of the instance_destination

You can define several routes that will be connected using gf.routing.route_bundle

filepath = "yaml_pics/routes_mmi.pic.yml"
Code(filepath, language="yaml+jinja")

name: routes_mmi

instances:
  mmi_bottom:
    component: mmi2x2
  mmi_top:
    component: mmi2x2

placements:
  mmi_top:
    x: 100
    y: 100

routes:
  optical:
    links:
      mmi_bottom,o4: mmi_top,o1
      mmi_bottom,o3: mmi_top,o2
    settings:
        cross_section: strip

c = gf.read.from_yaml(filepath)
c.plot()

../_images/2fb6dc95d5250d703564cd20e6b2a6770da264fe1498e0e1a2373e7259a23b6e.png

For placement you can define x, y, rotation and mirror:

Notice that mirror is defined as mirror: True and rotation as rotation: 90, mirror is equivalent to mirror_y, so if you want to mirror in the x axis you can use mirror and rotate 180 degrees.

mirror = """
instances:
  a:
    component: bend_circular

placements:
  a:
    mirror: True
"""
gf.read.from_yaml(mirror)

../_images/ce573e226ab7c4322538b7b93fd0df2c0fce2d450ac7371398d3248481165163.png

mirror = """
instances:
  a:
    component: bend_circular

placements:
  a:
    mirror: True
    rotation: 180
"""
gf.read.from_yaml(mirror)

../_images/007e85d5dd0b299107ac9ec2428e395b616e10496616197f9c88167231ec3f81.png

You can also add custom component_factories to gf.read.from_yaml

@gf.cell
def pad_new(size=(100, 100), layer=(1, 0)):
    c = gf.Component()
    compass = c << gf.components.compass(size=size, layer=layer)
    c.ports = compass.ports
    return c


gf.get_active_pdk().register_cells(pad_new=pad_new)
c = pad_new()
c.plot()

../_images/f6f83a457b6581c1c59c3106979932f0a81e28bcfe7a72ef012c77aa20a81474.png

filepath = "yaml_pics/new_factories.pic.yml"
Code(filepath, language="yaml+jinja")

name: new_factories
instances:
  bot:
    component: pad_new
  top:
    component: pad_new
placements:
  top:
    x: 0
    y: 200

c = gf.read.from_yaml(filepath)
c.plot()

../_images/88fffb47cf2f3a4c327a5eb47970ce73bd9d91b293b0593900a8cf1fa352471a.png

filepath = "yaml_pics/routes_custom.pic.yml"
Code(filepath, language="yaml+jinja")

instances:
  t:
    component: pad_array
    settings:
      port_orientation: 270
      columns: 3
  b:
    component: pad_array
    settings:
      port_orientation: 90
      columns: 3


placements:
  t:
    x: 200
    y: 400
routes:
  electrical:
    settings:
      start_straight_length: 150
      end_straight_length: 150
      cross_section: metal_routing
      allow_width_mismatch: True

    links:
      t,e11: b,e11
      t,e13: b,e13

c = gf.read.from_yaml(filepath)
c.plot()

../_images/1721701a3d71e91891a6695f89dcaede22cc09da50fd3694ec9266a56e3fd8f1.png

Also, you can define route bundles with different settings and specify the route factory as a parameter as well as the settings for that particular route alias.

Arrays#

You can also define arrays and connect to the array ports using the instance<column,row>,port_name syntax:

sample_array = """
instances:
  sa:
    component: straight
    array:
        columns: 2
        column_pitch: 20
        rows: 3
        row_pitch: 20

  b:
    component: bend_euler

connections:
    b,o1: sa<1.1>,o2

routes:
    b1:
        settings:
          cross_section: strip
        links:
            sa<0.0>,o2: sa<1.0>,o1

ports:
    o1: b,o2
    o2: sa<0.0>,o1
"""

gf.read.from_yaml(sample_array)

../_images/772479efc0aaa87e137e6e3a3e03824d637cddbd6c870a6a0f4e0a72c523caba.png

Arrays with routes#

You can also define groups of route ports in a group using the instance_name,port_base:index_start:index_end syntax:

For example, if you have an instance a with o3 and o4 ports, you can define a group of ports a,o:3:4 to connect the o3 and o4 ports of the instance a to the same port of another instance b.

port_array_optical = """
instances:
  a:
    component: nxn
  b:
    component: nxn

placements:
  b:
    x: 50
    y: 50
    mirror: True 
    rotation: 180

routes:
  optical:
    settings:
        cross_section: strip
    links:
      a,o:3:4: b,o:3:4
"""

gf.read.from_yaml(port_array_optical)

../_images/4a6831e94c7aa8a50f87bd71a6ce1e5ed467c08ec784d14f613c9ceac9c3700f.png

port_array_electrical = """
instances:
  t:
    component: pad_array
    settings:
      port_orientation: 270
      columns: 10
      auto_rename_ports: True
  b:
    component: pad_array
    settings:
      port_orientation: 90
      columns: 10
      auto_rename_ports: True

placements:
  t:
    x: 500
    y: 600

routes:
  electrical:
    settings:
      start_straight_length: 150
      end_straight_length: 150
      cross_section: metal_routing
      allow_width_mismatch: True
      sort_ports: True
    links:
      t,e:10:1: b,e:1:10
"""

gf.read.from_yaml(port_array_electrical)

../_images/d11dceb44b60d765fc797c0db640c64db968db856a4ec0815d602b1788eb1ba9.png

Jinja Pcells#

You use jinja templates in YAML cells to define Pcells.

from IPython.display import Code

import gdsfactory as gf
from gdsfactory.read import cell_from_yaml_template

jinja_yaml = """
default_settings:
    length_mmi:
      value: 10
      description: "The length of the long MMI"
    width_mmi:
      value: 5
      description: "The width of both MMIs"

instances:
    mmi_long:
      component: mmi1x2
      settings:
        width_mmi: {{ width_mmi }}
        length_mmi: {{ length_mmi }}
    mmi_short:
      component: mmi1x2
      settings:
        width_mmi: {{ width_mmi }}
        length_mmi: 5
connections:
    mmi_long,o2: mmi_short,o1

ports:
    o1: mmi_long,o1
    o2: mmi_short,o2
    o3: mmi_short,o3
"""
pic_filename = "demo_jinja.pic.yml"

with open(pic_filename, mode="w") as f:
    f.write(jinja_yaml)

pic_cell = cell_from_yaml_template(pic_filename, name="demo_jinja")
gf.get_active_pdk().register_cells(
    demo_jinja=pic_cell
)  # let's register this cell so we can use it later
Code(filename=pic_filename, language="yaml+jinja")

default_settings:
    length_mmi:
      value: 10
      description: "The length of the long MMI"
    width_mmi:
      value: 5
      description: "The width of both MMIs"

instances:
    mmi_long:
      component: mmi1x2
      settings:
        width_mmi: {{ width_mmi }}
        length_mmi: {{ length_mmi }}
    mmi_short:
      component: mmi1x2
      settings:
        width_mmi: {{ width_mmi }}
        length_mmi: 5
connections:
    mmi_long,o2: mmi_short,o1

ports:
    o1: mmi_long,o1
    o2: mmi_short,o2
    o3: mmi_short,o3

You’ll see that this generated a python function, with a real signature, default arguments, docstring and all!

help(pic_cell)

Help on function demo_jinja:

demo_jinja(*, length_mmi=10, width_mmi=5) -> gdsfactory.component.Component
    demo_jinja: a templated yaml cell. This cell accepts keyword arguments only
    
    Keyword Args:
        length_mmi: The length of the long MMI
        width_mmi: The width of both MMIs

You can invoke this cell without arguments to see the default implementation

c = pic_cell()
c.plot()

../_images/d848288df67fc4ae3c63a2ba4499351ebb1880a5e779b81e82e5bfe161f1b1da.png

Or you can provide arguments explicitly, like a normal cell. Note however that yaml-based cells only accept keyword arguments, since yaml dictionaries are inherently unordered.

c = pic_cell(length_mmi=100)
c.plot()

../_images/3b8cfe5b630752cb3be9e9741a7905f0253e0910d27f14bb1d27cc5286024772.png