CSN.1 allows the use of a user-defined function inside an exponent. The generated code will need to invoke this user-defined function. The C function name will be taken to be <typePrefix><functionName>, where <typePrefix> is the type prefix specified for the module in which the function is referenced and <functionName> is the name as it appears in the CSN.1. For example, "TS44018Msg_p".

Naturally, you will ned to define and implement the user function. You should name it as just described. It should return an integer type and accept an integer argument of a type that is compatible with the argument that is passed to the function in the CSN.1. For example: int TS44018Msg_p(OSUINT8 n).