netlist

Parse Altium designer (and probably other) netlist.

Description

A netlist describes all the electrical connection between then components of a Printed Circuit Board. A typical Altium Designer generated Netlist looks like this:

Wire List

<<< Component List >>>
100Ohms                         R1             0402
1uF                             C10            1206

<<< Wire List >>>

  NODE  REFERENCE  PIN #   PIN NAME       PIN TYPE    PART VALUE

[00002] VCC
        R1         1                      PASSIVE     myresistor
        C10        2                      PASSIVE     mycap

[00001] GND
        R1         2                      PASSIVE     myresistor
        C10        1                      PASSIVE     mycap

It contains

1. a very crude BOM (value, designator, package)
2. A list of all signal names and their connection.

In this example, 2 components are defined, and 2 nets are defined.

This module ignores the BOM, and concentrates only on nets.

SOM connection helper

On large System On Module, it can be very tedious and error-prone to define the different signal connection in device trees, or in an Hardware Design (for FPGA designs)

Using to the find_pins function, it is possible to retreive pin names from on a net name. You first have to define your module connectors and pins this way:

pz_pins = {
    "JX1" : {
        "9" : "R19",
        "10" : "T19",
        "11" : "T11",
        "12" : "T12",
        "13" : "T10",
        "14" : "U12",
    },
    "JX2" : {
        "13" : "G14",
        "14" : "J15",
        "17" : "C20",
        "18" : "B19",
    },
}

in this example, the SOM has 2 connectors which are seperate parts on the PCB, called "JX1" and "JX2". Pin 9 of connector JX1 is named pin "R19" internally in the SOM.

This also works on components which have a single part (in this example only the first 2 pins are described):

stmf32F407_64_pins = {
    "1" : "VBAT",
    "2" : "PC13",
}

Automatic Checks

Common Schematic capture mistakes can be caught analyzing the Netlist. The most common is probably unconnected pins due to a bad net label.

check_orphans lists all nets that have (by default) less than 2 connections.

Command-line tool

You can call python -m netlist to invoque the command-line tool. Use the built-in help to lear to use it.