ISA: C6000; All CCS after v2.20:
This warning message is generated whenever a `.ref` directive is used to reference a symbol in an assembly file included using an `.include` directive; the symbol being defined using the `.equ` directive in the source
This symbol should be used in the included assembly file without the `.ref` directive. The removal of the `.ref` directive in the included assembly file will eliminate this warning message. This non-requirement of the
`.ref` directive in the included assembly file is detected only by CCS 2.20 and hence the other versions do not generate this warning message.