Keil AA ARM Assembler

Conditional Assembly Controls: Set assigns numeric values to variables that are used in $IF and $ELSEIF directives to control conditional assembly sections. The variable names must conform to the standard symbol conventions and are administered separately so that they cannot interfere with other assembly symbols.

Reset clears previous Set assignments that are entered in the options dialog of a higher Target or Group level.
Macro Preprocessor: Enables the Standard Macro Processor allows you to define and use macros in your ARM assembly programs. The Standard Macro Syntax in compatible with that used in many other assemblers.

When enabled the Assembler interprets symbol names using both uppercase and lowercase characters and outputs them to the object file with the case preserved. Symbols are case-sensitive. When disabled the Assembler converts all symbol names to uppercase.

Include Paths: Allows you to supply one or more paths to search when processing an $INCLUDE file directive.
Misc Controls: Specify any assembler directive for which there is no individual dialog control.
Assembler Control String: Displays the current directives at the assembler command line.