I am using the B-L475E-IOT01A kit. I want to use spsgrf sub GHz module. There are only libraries available for that. Is there any reference manual available that can be referred to?

[DMitt.3]

I want to understand more about registers and RF activities.

[Tesla DeLorean]

https://www.st.com/resource/en/user_manual/dm00189294-getting-started-with-xcubesubg1-sub1-ghz-rf-software-expansion-for-stm32cube-stmicroelectronics.pdf

https://www.st.com/en/embedded-software/x-cube-subg1.html

https://www.st.com/resource/en/datasheet/spirit1.pdf

Beyond this I'd half expect radio technical docs to be available via local sale office, with an NDA in place.