Translating Assembly Language to Machine Language

1. Translating Assembly Language to Machine Language

2. An example program Notes: Parts of lines appearing after "*" are comments Labels in left hand column are names associated with the corresponding value

3. Instructions and addresses Notes: Each instruction will occupy one location in Woody's main memory Comments are ignored in the translation process, so they have been removed here

4. Pass 1: Create a symbol table

5. Pass 1: Create a symbol table

6. Pass 1: Create a symbol table

7. Pass 1: Create a symbol table

8. Pass 2: "Assemble" the machine code 1 Machine Code

9. Pass 2: "Assemble" the machine code 2 Machine Code

10. Pass 2: "Assemble" the machine code 3 Machine Code

11. Pass 2: "Assemble" the machine code 4 Machine Code

12. Pass 2: "Assemble" the machine code 5 Machine Code

13. Pass 2: "Assemble" the machine code 6 Machine Code

14. Pass 2: "Assemble" the machine code 7 Machine Code

15. Pass 2: "Assemble" the machine code 8 Machine Code

16. Pass 2: "Assemble" the machine code 9 Machine Code

17. Pass 2: "Assemble" the machine code 10 Machine Code

18. Pass 2: "Assemble" the machine code 11 Machine Code

19. Pass 2: "Assemble" the machine code 12 Machine Code

20. Pass 2: "Assemble" the machine code 13 Machine Code

21. Pass 2: "Assemble" the machine code 14 Machine Code

22. Pass 2: "Assemble" the machine code 15 Machine Code

23. Pass 2: "Assemble" the machine code 16 Machine Code

24. Pass 2: "Assemble" the machine code 17 Machine Code

25. Pass 2: "Assemble" the machine code 18 Machine Code

26. Pass 2: "Assemble" the machine code 19 Machine Code

27. Pass 2: "Assemble" the machine code 20 Machine Code

28. Pass 2: "Assemble" the machine code 21 Machine Code

29. Pass 2: "Assemble" the machine code 22 Machine Code

30. Pass 2: "Assemble" the machine code 23 Machine Code

31. Pass 2: "Assemble" the machine code 24 Machine Code

32. Pass 2: "Assemble" the machine code 25 Machine Code

33. Pass 2: "Assemble" the machine code 26 Machine Code

34. Pass 2: "Assemble" the machine code 27 Machine Code

35. Pass 2: "Assemble" the machine code 28 Machine Code

36. Pass 2: "Assemble" the machine code 29 Machine Code Literal integer values are translated into binary using the signed magnitude representation

37. Pass 2: "Assemble" the machine code 30 Machine Code 510 = 000001012 in 8 bit signed magnitude representation

38. Pass 2: "Assemble" the machine code 31 Machine Code 510 = 000001012 in 8 bit signed magnitude representation

39. Pass 2: "Assemble" the machine code 32 Machine Code

40. Pass 2: "Assemble" the machine code 33 Machine Code

41. Pass 2: "Assemble" the machine code Machine Code This sequence of values, stored in a file, forms the executable for this program.

42. Observations • This is a very mechanical process. The program that does this job is called an assembler. • Each different computer architecture (Intel Pentium, PowerPC, IBM Cell, etc.) has its own assembly language. • The instructions in assembly language correspond one-to-one with instructions in the target architecture's machine language. • An executable for a program consists of a file containing the machine language instructions for the program.