PicC 9.50 dsPIC Manual.pdf

HI-TECH C Assembly LanguageMacro AssemblerTable 4.3: ASDSPIC numbers and basesRadixBinaryOctalDecimalHexadecimalFormatdigits 0 and 1 followed by Bdigits 0 to 7 followed by O, Q, o or qdigits 0 to 9 followed by D, d or nothingdigits 0 to 9, A to F preceded by Ox or followed by H or h4.3.3.1 Special Comment StringsSeveral comment strings are appended to assembler instructions by the code generator. These aretypically used by the assembler optimizer.The comment string ;volatile is used to indicate that the memory location being accessed inthe commented instruction is associated with a variable that was declared as volatile in the Csource code. Accesses to this location which appear to be redundant will not be removed by theassembler optimizer if this string is present.This comment string may also be used in assembler source to achive the same effect for locationsdefined and accessed in assembly code.4.3.4 Constants4.3.4.1 Numeric ConstantsThe assembler performs all arithmetic with signed 32-bit precision.The default radix for all numbers is 10. Other radices may be specified by a trailing base specifieras given in Table 4.3.Hexadecimal numbers must have a leading digit (e.g. 0ffffh) to differentiate them from identifiers.Hexadecimal digits are accepted in either upper or lower case.Note that a binary constant must have an upper case B following it, as a lower case b is used fortemporary (numeric) label backward references.In expressions, real numbers are accepted in the usual format, and are interpreted as IEEE 32-bitformat.4.3.4.2 Character Constants and StringsA character constant is a single character enclosed in single quotes ’.Multi-character constants, or strings, are a sequence of characters, not including carriage returnor newline characters, enclosed within matching quotes. Either single quotes ’ or double quotes "70