Jieli has open-sourced some chips and released documentation, but compared to companies like ST and TI, the documentation is really poor. 

Jieli's documentation consists of three parts: SDK accompanying documents, online documents, and internal documents. 

SDK accompanying documents: These come with the SDK and introduce basic operations and functions, such as the SDK introduction manual and UI editing manual, but they are not very detailed. 

Online documents: Jieli's FAEs (Field Application Engineers) update these documents in real-time and add various detailed explanations. 

Internal documents: These are the chip reference manuals, containing detailed chip functions and registers. So far, none of these documents have been seen leaked.