Question

The following 32-bit binary word written in hexadecimal format represents a single RISC-V assembly instruction. What is the RISC-V instruction format and specific assembly language instruction?

0xfe810113

Answer 1

Solution -:

This 32- bit instruction given in hexadecimal is I-Format instruction.

and function performed by this instruction is ADDI (ADD immediate)

Explanation -:

In risc-v technology instruction size is 32-bit.

different type of instruction format are

So here rightmost 7 bits are for opcode.

and opcode for different format is different.

In given instruction opcode is 0010011. This opcode belongs to I-Format risc-v instruction. So that's how format is identified.

Now instruction format for I type is given below

Here

immediate is of 12-bits (immediate word)

rs1 is of 5-bits (register oprand)

fun3 is of 3-bits (function to be performed)

rd is of 5-bits (destination register)

opcode is of 7-bits

So in given question fun3 is 000 that is ADDI (ADD immediate)