Assemblers
Design of 2-Pass AssemblersAgenda Introduction Advanced
Assembler DirectivesORIGINEQULT ORGPass I of the AssemblerData
Structure used in Pass IOPTAB
SYMTABLITTABPOOLTABAlgorithmIntermediate codeDeclaration and
Assembler Directive Processing Pass II of the
AssemblerIntroductionSourceProgramAssemblerObjectCodeLoaderExecutable
CodeLinkerConvert mnemonic operation codes to their machine
language equivalentsConvert symbolic operands to their equivalent
machine addresses Build the machine instructions in the proper
formatConvert the data constants to internal machine
representationsWrite the object program and the assembly
listingIntroductionTwo Pass Assembler Read from input lineLABEL,
OPCODE, OPERANDPass 1Pass 2 IntermediatefileObject
codesSourceprogramOPTABSYMTABSYMTABIntroduction: Design of 2 - Pass
AssemblerPass 1Separate the Symbol, Mnemonic opcode and operand
fieldsBuild the symbol tablePerform LC Processing Construct
Intermediate RepresentationPass 2Synthesize the target
programAdvanced Assembler DirectivesORIGINEQU
Advanced Assembler DirectivesORIGINEQU
Syntax: ORIGIN < Address Specification>
Advanced Assembler DirectivesORIGINEQU
Syntax: EQU
E.g. MAXLENEQU4096Pass I of AssemblerPass I Uses following Data
StructuresOPTABSYMTABLITTABPOOLTABPass I of AssemblerPass I Uses
following Data StructuresOPTAB : A Table of Mnemonics & related
infoSYMTABLITTABPOOLTAB
Pass I of AssemblerPass I Uses following Data
StructuresOPTABSYMTAB: Symbol TableLITTABPOOLTAB
Pass I of AssemblerPass I Uses following Data
StructuresOPTABSYMTABLITTAB: Table of Literals used in
programPOOLTAB
Pass I of AssemblerPass I Uses following Data
StructuresOPTABSYMTABLITTABPOOLTAB: A table of information
concerning literal pool
Algorithm
Algorithm
