17.4.3. Return from Function

Try these first

1. 1.

   What is the purpose of a program counter in an instruction sequence?

   Hint

   Think about how a program knows which instruction to execute next.

2. 2.

   Define what an unconditional jump does.

   Hint

   Consider what happens when you encounter 'jump 3000' in a program.

3. 3.

   What does an unconditional jump do?

   • Continues to the next instruction
   • Jumps to a specified address
   • Stops the program

   Hint

   Focus on what 'unconditional' means.

4. 4.

   If the zero flag is not set, what happens during a conditional jump?

   • True
   • False

   Hint

   Think about how conditions affect decision-making in programs.

5. 5.

   Consider a program that jumps to address 5000 when an operation results in a zero flag being set. Outline how the program would proceed if the zero flag were not set.

   Hint

   Focus on the implications of different flag states during conditional jumps.

6. 6.

   Explain what might happen if a function call does not properly save the current program counter before executing, specifically in a nested function call scenario.

   Hint

   Think about how multiple layers of function calls rely on correctly managing their respective PC states.