ITPEC FE Morning April 2023 Question 2

Logical Right Shift — shift all bits right, fill with zeros from the left.

Convert ABCD hex to binary in a 32-bit register:

• •A = 1010, B = 1011, C = 1100, D = 1101
• •Full: 0000 0000 0000 0000 1010 1011 1100 1101

Shift right by 2 bits (drop 2 rightmost, insert 2 zeros on left):

• •Result: 0000 0000 0000 0000 0010 1010 1111 0011
• •Grouped: 2 A F 3 → `2AF3`

Why not others:
- (b) 6AF3 — incorrect shift calculation
- (c) AF34 — resembles a left shift by 4 bits, not a right shift by 2
- (d) EAF3 — would imply sign-extension (arithmetic shift), not logical shift

Key rule: Logical right shift by n bits = integer division by 2^n, with zeros filling the MSB. For 2 bits: divide by 4.

AI-generated — may contain errors