Question

Provide the type, assembly language instruction, and binary representation of instruction described by the following MIPS fields:

op= $\mathbf{0}\mathbf{\times }\mathbf{23}$, rs=1, rt=2, const=$\mathbf{0}\mathbf{\times }\mathbf{4}$

Short answer

The type of instruction is I-type. The assembly language instruction is lw. The binary representation of instruction is 1000 1100 0010 0010 0000 0000 0000 0100.

Step-by-step solution

Identify the types of MIPS instructions

Each MIPS instruction is 32 bit long. MIPS instructions have an opcode field that specifies the operation of the instruction. MIPS instructions are divided into three categories: I-type, J-type, R-type.

Identify I-type instruction

The I-type instruction has opcode, the first register source operand, the second register source operand and address. In this instruction, the operand is a constant within the instruction itself. The type of instruction described by the MIPS field is an immediate instruction. The instruction has four fields, opcode, rs, rt, and constof 16-bit representing the address. Therefore, the instruction type is I-type.

Assembly language instruction

The MIPS instruction given provides the opcode, rs and rt fields. Along with these fields, the address field is provided. Load word (lw) command copies the value stored at a memory address to a destination register. The offset is the instruction is 16-bit value. The instruction loads the data from the specified 16-bit address. It makes the instruction load word (lw). Load word (lw) command copies the value stored at a memory address to a destination register. Therefore, thelw assembly language instruction is described by the MIPS fields.

Binary representation of instruction

The MIPS instruction is:

op= $0\times 23$, rs = 1, rt = 2, const = $0\times 4$

op specifies the instruction’s operation and is of 6-bits. rs is the source register that is used to specify the register containing the first operand and is of 5-bits. rt is a target register that is used to specify register containing the second operand and is of 5-bits. The last 16-bits are used for address in I-format. The I-format for MIPS is:

op	rs	rt	address
100011	00001	00010	0000 0000 0000 0100

Hence, The binary representation is 1000 1100 0010 0010 0000 0000 0000 0100 0x8C220004.