Features:
• Translates Assembler source programs into object code
• Extremely fast assembling
• Supports all the microcontrollers in the AT90S family
• Powerful Macro capabilities
• Supports all standard output formats
• Easy to use MS-Windows interface
• Editor included in MS-Windows version
• Jump to next/previous error
• Also available in MS-DOS command line version

Powerful Macro Capabilities
The Assembler contains powerful macro capabilities, enabling the user to build a virtual instruction set which is structures
of ordinary AVR instructions. For example, this macro does a 16 bit subtraction:
;
; SUB16 macro definition

; The macro subtracts a 16 bit constant from a register
; pair. A call to the macro is done by
; SUB16 Regh,Regl,Const
;
.MACRO SUB16 ; Macro name
subi$1,low($2) ; subtract low byte
sbci $0,high($2) ; subtract high byte
.ENDMACRO
; ...
; Call the macro
ldi r16,low(0x3400) ; set values in registers
ldi r17,low(0x3400) ;
SUB16 r17,r16,0x23a0 ; compute 0x3400-0x23a0

Assembly Directives
The assembler supports a number of directives making the application development easier. In addition to the directives for
macro generation and control, the assembler contains directives for:
• Including files. Included files can be nested.
• Set program origin.
• Symbol usage. The user can define symbols and labels and refer to these throughout the assembly program.
• Constant data initialization. The user can do constant initialization. Constants will be placed in the Flash
program memory.
• List file control.
• Support of expressions in a C-like syntax.