16-bit-cpu-MIPS

implementation of 16 bit CPU (MIPS architecture) for Computer Architecture course

Op-code and Function Bits Mapping

Opcode	Instruction Type	ALU-OP	Func	Instruction Operation	Registered ALU Op	ALU Control Bits
000	R-type	10	0000	ADD	ADD	0010
000	R-type	10	0010	SUB	SUB	0110
000	R-type	10	0100	AND	AND	0000
000	R-type	10	0101	OR	OR	0001
001	lw	00	xxxx	Load word	ADD	0010
010	sw	00	xxxx	store word	ADD	0010
011	Beq	01	xxxx	branch if equal	SUB	0110
100	Jump	XX	xxxx	Jump

ALU-op	Func	ALU-Control-Bit
10	0000	0010
10	0010	0110
10	0101	0001
10	xxxx	000
00	xxxx	001
00	xxxx	001
01	xxxx	011

ALU-Control-0 = (ALU-OP_1.F0)

ALU-Control-1 = NOT(ALU-OP-1) + NOT(F2)

ALU-Control-2 = (ALU-OP-1.F1) + ALU-OP-0

ALU-Control_3 = 0

Instruction Set

Input/Output	Opcode	R-type	lw	sw	Beq	Jump
Input	op2	0	0	0	0	1
	op1	0	0	1	1	0
	op0	0	1	0	1	0
Output	RegDst	1	0	x	x	x
	RegWrite	1	1	0	0	0
	ALUSrc	0	1	1	0	x
	MemRead	0	1	0	0	0
	MemWrite	0	0	1	0	0
	MemtoReg	0	1	X	X	X
	Branch	0	0	0	1	0
	Jump	0	0	0	0	1
	Alu-Op-1	1	0	0	0	x
	ALU-OP-0	0	0	0	1	x

Instruction Format

Opcode	RS	RT	RD	Function