126 lines
4.6 KiB
Markdown
126 lines
4.6 KiB
Markdown
# <span style="color: #5573fa;">mxPIC Quick-Reference Style Guide</span>
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Welcome to the collaboration of the repository of **mxPIC** program. This repository is aimed for a self-designed PDK that based on ***nazca***, ***gdstk*** and other libraries for the functional build up of photonic integrated circuits (PIC).
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This is the fast-track guide to contributing to **mxPIC**. Adherence to these rules is mandatory to pass the automated CI/CD pipeline.
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### <span style="color: #ff57c7;">0. Installation dependencies</span>
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- python 3.10.1
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- nazca 0.5.13
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- gdstk 1.0.0
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- numpy 1.22.3
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- pandas 1.3.3
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- matplotlib 3.4.3
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- Cython 3.2.4
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- Sphnix 7.4.7
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- myst-parser 3.0.1
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- sphinx-rtd-theme 3.1.0
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```
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pip install sphinx myst-parser sphinx-rtd-theme gdstk==1.0.0
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```
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## <span style="color: #ff57c7;">1. File & architecture</span>
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The repository have an archtecture like this.
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```
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mxpic_forge/
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├── primitives/
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│ ├── edge_couplers/
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│ │ └── EC_dual_layer_px3.py
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│ ├── multimode_interferomters/
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│ ├── directional_couplers/
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│ ├── grating_couplers/
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│ └── microring_modulators/
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├── composite/
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│ └── mach_zender_modulators/
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├── electronics/
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│ ├── resistors/
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│ ├── inductors/
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│ ├── vias/
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│ └── pads/
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├── others/
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├── structures/
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├── routing/
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├── foundries/
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└── docs/
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└── source/
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└── conf.py
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```
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## <span style="color: #ff57c7;">2. Annotation & Documentation</span>
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We strictly use **Type Hints** (PEP 484) and **NumPy-Style Docstrings**.
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* <span style="color: #d2a8ff;">**Rule:**</span> Every function MUST have its parameter types and return type explicitly declared.
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* <span style="color: #d2a8ff;">**Rule:**</span> Use `"""` for docstrings, broken into `Parameters` and `Returns` sections.
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```diff
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- class Waveguide(length, width):
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- """Builds a Mach-Zehnder."""
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- pass
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+ class Waveguide(length: float, width: float = 0.5) -> nazca.Cell:
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+ """
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+ Generates an MZM layout.
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+
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+ Parameters
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+ ----------
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+ length : float
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+ Arm length in microns.
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+ width : float, optional
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+ Waveguide width in microns.
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+
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+ Returns
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+ -------
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+ list[tuple]
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+ Polygon vertices.
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+ """
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+ pass
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```
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---
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## <span style="color: #ff57c7;">3. Class mangement of devices</span>
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The devices are divided into four major types, which is <span style="color: #d2a8ff;">**primitives, composite, electronics, and others**</span>. All photonic and electronic devices are built within the for types.
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In the definitial of classes, compulsary keys are required, including **name** , **show_pins** , all defaults are None.
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All classes are cored at the **cell** class of **nazca**, which is generated through an internal method named "generate_gds"
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``` python
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class GratingCoupler():
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def __init__(self,name:"str"=None,....,show_pins:bool=None)
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...
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...
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self.cell = self.generate_gds() ## the generation of cell
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def generate_gds(self) -> nazca.Cell:
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""" Creating the cell of the device """
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with nd.Cell(name=self.name,inst) as C:
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return C
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```
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---
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## <span style="color: #ff57c7;">4. Port information formatting</span>
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The basic routing algorthium is based the information between nodes, which is the **pin** attribute inside each file. The formatting of **pin** name will be important.
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**<span style="color: #bf0000;">Note</span>**: The pin name should only be related to different functionalities instead of material, layer or shaped. Say, the pin name of a *silicon directional coupler* is the same as a *silicon nitride directional coupler*.
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|Catagory| Prefix | name | index | expample | device instance
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|---|---|---|---|---|---|
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| Optical| opt_ | a | 1~x | opt_a_1 | direction_coupler
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| Optical (Sinlge IO to waveguide)| opt_ | a_ | 1~x | opt_a_1 |grating_coupler
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| Electrical| ele_ | a | 1~x | ele_a_1 | heater/resistor
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| PN diodes| ele_ | cathode/anode | 1~x | ele_anode_1 | modulator/p-i-n waveuigde
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| Transistors (BJT)| ele_ | base/em/collector | 1~x | ele_colloctor_1 | BJT
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| Transistors (MOS)| ele_ | gt/su/dr | 1~x | ele_gt1 | MOSFET
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## <span style="color: #ff57c7;">5. Layer and cross-sections</span>
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Inside **nazca**, an important feature is the concept of **cross-sections (xs)**. Typically, **xs** is a conbination of different layers which is required by the foundry DRC. Below is a example in Silterra tapeout.
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``` python
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nazca.add_xsection("strip")
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nazca.add_layer_to_xsection("WG_HM",growx=2,growy=2)
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nazca.add_layer_to_xsection("WG_STRIP",growx=2,growy=2)
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```
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