XuanTie C906 is not open-source. They just open-source a light version of the C906, the OpenC906. For instance OpenC906 does not contain the vector extension.

XuanTie C906 is not open-source. They just open-source a light version of the C906, the OpenC906. For instance OpenC906 does not contain the vector extension. But even the OpenC906 is only partially open-source. They only disclosed verilog code generated by an internal tool, so the real design source code is not open. Worse, they don't open source testbenchs which makes any modification or verification very tedious.