Thank you Eckhard,
I think we misunderstood the question.
Diego seem to want to create a TBDML based on NE64 and not to debug/prog NE64.
Diego,
Have you investigated the DBUG12 tool ?
This is a software based on S12DP256 to program other S12 via BDM from a Terminal (so Serial port).
I doubt it fully matches what you are looking for but you need to know that the DLL to talk with CodeWarrior is not Open Source. Therefore porting the software to an S12 may not be easily possible.
Cheers,
Alban.