Protocol Analyzer SDK
Instructions for loading existing custom analyzers into the Logic software can be found here: Import Custom Low Level Analyzer
The Saleae Protocol Analyzer SDK lets you make your own custom protocol analyzers. The framework is very flexible. You can do everything we can do (we use the same SDK). You'll be creating a shared library (.dll, .so, or .dylib) that will be loaded by the Logic software as a plugin.
While there are many advantages to providing the SDK in this format, implementation of a custom protocol will probably take an experienced C++ developer at least a full day, and possibly up to a week, to complete. You will probably want to have had considerable programming experience, probably significant C++ experience, before taking it on.
That said, you can get away with implementing only a small part of the full capability of the analyzer. For example, you could have only one setting (the input channel(s) to use), and you could skip creating simulated data to test against, not bothering to provide for data export or tabular display.
Further, by default, you will start out with a fully featured and maximally simple analyzer—SimpleSerialAnalyzer. The documentation will walk you through how to modify it to suit your needs, as well as what parts can be left empty.

Latest Analyzer SDK Release

Documentation and Getting Started

The documentation for the Analyzer SDK can be found below:
Alternatively, to get started, you can review the Setup guide below. We will be working with the provided Sample Analyzer above.
The Sample Analyzer includes build instructions in its included Readme file.

Installing your Custom Analyzers

Protocol Analyzers Source Code

Legacy 1.1.14 Release