=                Create absolute symbol                             Directive

  name=expression

    Defines or redefines a numeric equate. name can either be a new symbol
    name, or a symbol that you previously defined with =. expression must
    evaluate to either a constant or an address within a segment.

    You can't use = to assign strings or to redefine keywords or
    instruction mnemonics; you must use EQU to do these things.

    The = directive has far more predictable behavior than the EQU
    directive in MASM mode, so you should use = instead of EQU wherever
    you can.

    Example:    BitMask = 1                   ; Initialize bit mask
                LABEL BittBl BYTE
                   REPT 8
                      DB   BitMask
                      BitMask = BitMask * 2   ; Shift the bit to left
                   ENDM