Lecture 19 Objectives


At the end of today's class you should

KNOW:

BE ABLE TO:

Sample Exam Question:

(Problem 9.16 from the textbook) The two code sequences a and b are assembled separately. There are two errors. Identify the bugs and describe why each bug will cause an error, and identify whether the errors will be detected at assembly time or at link time.

a.         .ORIG x3200
     SQRT  ADD   R0, R0, #0
           ; code to perform square root function
           ; and return the result in R0
           RET
           .END


b.         .EXTERNAL SQRT
           .ORIG x3000
           LD    R0, VALUE
           JSR   SQRT
           ST    R0, DEST
           HALT
    VALUE  .FILL x30000
    DEST   .FILL x0025
           .END