Question

Choose typical program control instructions.

• A. BR, SKP, RET, TST
• B. BR, BUN, CALL, XCG
• C. JMP, BUN, LDA, XCG
• D. CALL, RET, OUT, IN

Hint:

Program Control Instructions modify the sequence of execution. Examples: BR (Branch), JMP (Jump), CALL, RET, SKP, and TST.

Answer 1

The Correct Option is A

Concept: Program control instructions alter the normal sequence of program execution. Instead of executing instructions sequentially, they change the flow of control depending on conditions or subroutine requirements. Examples include:
• Branch (BR)
• Skip (SKP)
• Return (RET)
• Test (TST) These instructions are essential for loops, decision making, and subroutine handling.

Step 1: Understand program control instructions.
Program control instructions determine which instruction will be executed next. They affect the Program Counter directly or indirectly.

Step 2: Examine Option (A).
BR = Branch SKP = Skip RET = Return TST = Test All of these are program control instructions.

Step 3: Examine the remaining options.
XCG represents exchange operations. LDA is a data transfer instruction. IN and OUT are input-output instructions. Therefore these options contain instructions that are not purely program control instructions.

Step 4: Write the final answer.
Hence the correct group of program control instructions is \[ \boxed{\text{BR, SKP, RET, TST}}. \] Therefore option (A) is correct.