December 1998
CS202: COMPUTER ARCHITECTURE AND DATA COMMUNICATION

QUESTION 3

Total Marks: 20 Marks

 Click here to access other questions

Click to access
SUGGESTED SOLUTIONS
for Question 3

 
(a) Define the following terms: [6]
(i) stack pointer;
(ii) stack limit;
(iii) stack overflow

 
(b) A subroutine call operation begins as: [4]
SP <-- SP + 1         (increment stack pointer)
Mem[SP] <-- PC     (pushes content to PC onto the stack)
PC <-- Starting address of subroutine    (transfer control to subprogram)

 
Show, in similar terms, what operations take place when control returns from the subroutine to the main calling program.

 
(c) State two difference between a subroutine and an interrupt.

 

 [4]
(d) Stacks are often used to evaluate logical and arithmetic expressions. Given a stack in a O-Address format, write a program to evaluate the following expression:

X := ((A * B / C) + (D + C - F)) / (G - H)

What maximum stack size (stack depth) is needed in order to execute your program? Explain your answer.

 [6]