How to calculate Nref? (3gpp ts 38.212)

In subclause 5.4.2.1, C in the equation of Nref refers to the number of code blocks of the transport block. But it is not very clear to me if “the transport block” means the transport block under channel coding, or the transport block of size TBS_LBRM and coding rate 948/1024? Somebody please be kind to explain this and tell how to reach that conclusion. Thanks.

Some expert please have a look at the parameter setup of the nodeb or some device and show how to calculate Nref.