How to convert the 14 digit POA to the true POA value?

I’m trying to compare the POA calculated from CIR and the POA from dwt_readdiagnostics().
In DW3000, POA readings are uint16 type in the diagnostic data. But there is no explanation on how it can be converted to radians in the manual.
The manual says POA is stored as a 14-digit number. I’ve tried 2-digit integer + 12-digit fractional part, and 3-digit integer + 11-digit fractional part. But the first one gives a max POA of 4 radians, and the latter one gives a max POA larger than 2pi.
Could someone explain how to translate the POA reading in the result of dwt_readdiagnostics()?
Thanks.