SPNU118Z September 1995 – March 2023 66AK2E05 , 66AK2H06 , 66AK2H12 , 66AK2H14 , AM1705 , AM1707 , AM1802 , AM1806 , AM1808 , AM1810 , AM5K2E04 , OMAP-L132 , OMAP-L137 , OMAP-L138 , SM470R1B1M-HT , TMS470R1A288 , TMS470R1A384 , TMS470R1A64 , TMS470R1B1M , TMS470R1B512 , TMS470R1B768
The $$defined directive returns true/1 or false/0 depending on whether the name exists in the current substitution symbol table or the standard symbol table. In essence $$defined returns TRUE if the assembler has any user symbol in scope by that name. This differs from $$isdefed in that $$isdefed only tests for NON-substitution symbols. The syntax is:
$$defined( substitution symbol name )
A statement such as ".if $$defined(macroname)" is then similar to the C code "#ifdef macroname".
See Section 13.4.2 and Section 13.4.3 for the use of .define and .undef in assembly.