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?

0xfe814113

that is the question

Answer 1

If 0xfe814113 translated into binary, it turns out,

1111 1110 1000 0001 0100 0001 0001 0011

Following RISC V Instruction manual, first 7 bits provide opcode of the instruction. In this case it's an immediate instruction. Bits 12 to 14 represent function. In this case it is xor function. Bits 7 to 11 represent destination register, which is R2. Bits 15 to 19 represent source register, which is R2. Bits 20 to 31 represent immediate value, which comes out -24 (decimal).

This RISC V Instruction format xori R2, R2, -24 (decimal)