CSE JRF PROGRAMMING

DIFFERENCE BETWEEN ONE PASS AND TWO PASS ASSEMBLERS:-

• ONE PASS ASSEMBLER PASSES 

1. OVER THE SOURCE FILE EXACTLY ONCE
2. IN THE SAME PASS COLLECTING THE LABELS, RESOLVING FUTURE REFERENCES AND DOING THE ACTUAL ASSEMBLY. 
3. THE DIFFICULT PART IS TO RESOLVE FUTURE LABEL REFERENCE AND ASSEMBLE CODE IN ONE PASS.

• TWO PASS ASSEMBLER DOES TWO PASSES OVER THE SOURCE FILE.              IN THE FIRST PASS-

1. ALL IT DOES LOOKS FOR LABEL DEFINITIONS AND INTRODUCES THEM IN THE SYMBOL TABLE IS .

          IN THE SECOND PASS-

     2.  AFTER THE SYMBOL TABLE IS COMPLETE, IT DOES THE ACTUAL ASSEMBLY           BY TRANSLATING THE OPERATIONS AND SO ON.