Now i have already finished my C routine with MC9S12VR series MCU ,my interface is USB mutilink ,how to encrypt my source code of C language and then download it to the MCU to prevent others illegal reading my source codes from MCU?do CW have this function?if not do other device or software own this function? who can give me some advices? thank you very much.
Source code enryption available in CW has nothing to do with MCU. Having CW PRO licence you enable encryption in project settings and compile. Instead of producing object o-files, CW compiler will produce encrypted source files which are not human readable and have file extension like *.c_e . You can give these encrypted files to your consumer and he will be able to compile them with CodeWarrior but won't be able to see C source or edit them.
MCU security is access prevention to flash and EEPROM. To enable MCU security you need to program byte at global address 3_FF0F with lowest order bits set to 00,01 or 11. See register FSEC description.