GATE ECE 2024 | Question: 17

Question

A machine has a $32$-bit architecture with $1$-word long instructions. It has $24$ registers and supports an instruction set of size $40$. Each instruction has five distinct fields, namely opcode, two source register identifiers, one destination register identifier, and an immediate value. Assuming that the immediate operand is an unsigned integer, its maximum value is $\_\_\_\_\_\_$.

Answer 1

A machine has a 32-bit architecture with 1-word long instructions.

So, 1 word = 32 bits.

Opcode size = 6 bits.

Number of bits to encode registers = 5.

Number of bits available for immediate value: $32 - 6 - 5 - 5 - 5 = 11$ bits.

Since the immediate operand is an unsigned integer, its maximum value is $2^{11} - 1 = 2047.$