Question

In these exercises assume the text begins at location 0x00400000.

1. Translate each of the following instructions to machine language:
(a) xori $v0, $a3, 0xffff

Answer 1

The MIPS assembly instruction 'xori $v0, $a3, 0xffff' translates to machine language as '0x38E7FFFF'. The translation involves encoding the opcode, source register, target register, and the immediate value into a binary format, which is then converted to hexadecimal.

Step-by-step explanation:

The student asked for the translation of an assembly instruction to machine language, specifically for the instruction xori $v0, $a3, 0xffff. In MIPS assembly language, xori stands for "bitwise exclusive or immediate", which performs a bitwise exclusive OR operation between a register and an immediate value and stores the result in a register. The opcode for xori is 001110, and it is a type I instruction.

MIPS assembly instructions are encoded as follows: the first 6 bits represent the opcode, the next 5 bits represent the source register (rs), followed by 5 bits for the target register (rt), and the last 16 bits are for the immediate value.

For xori $v0, $a3, 0xffff, the source register ($a3) has a register number of 7, and the target register ($v0) has a register number of 2. The immediate value is 0xffff.

This results in the following binary representation: 001110 00111 00010 1111111111111111.

To use this in a machine-readable format, it is converted to hexadecimal: 0x38E7FFFF.

Hence, the MIPS machine language translation for xori $v0, $a3, 0xffff is 0x38E7FFFF.