© Thomas Kunz 2000
SCE 574
68
Anatomy of an Assembler Language
A)
Expressions
(1)
Represent numbers, characters, strings (0,‘0’,“AB”)
(2)
Labels for addresses or constants (“STEP2”, “MAX”)
(3)
Operators (+,-)
(4)
Brackets ()
(5)
Location counter - special reference to current memory location
B)
Register mnemonics
äNames
that represent registers R0, R1, or AX ..
C)
Instruction mnemonics
äNames
that identify instructions MOV
D)
Addressing mode syntax
äIdentify
whether a word contains a value, reference (pointer), or other.... (will see more
later)
E)
Instruction statements
äOperation
and operands