kerrytang / mips_singlecycle

This is a single-cycle, functional MIPS processor simulator according to the reduced MIPS R300A ISA

MIPS Single Cycle

A single-cycle, functional processor simulator according to the reduced MIPS R3000 ISA. This project is developed for 2014 Spring CS410001-Computer Architecture course offerd by Prof. Ren-Song Tsay @ National Tsing Hua University

Characteristic

• To meet the needs in course, both the instruction memory and data memory are changed into little-endian format.
• Register 0 is a hard-wired constant 0; any attempt to write to register 0 takes no effect.
• Assume that both the instruction memory and data memory are of 1K bytes size.
• An error handler is implemented to deal with erroneous instruction executions.
• The execution of the single cycle processor simulator would terminate after executing the halt instruction.

Input format

For each test case, all registers, except PC and $sp, are initialized to 0’s; other initial conditions are specified in the following two files.

• iimage.bin: The instruction image (little-endian format, encoded in binary). The first four bytes indicate the initial value of PC, i.e. the starting address to load the instruction image. The next four bytes specify the number of words to be loaded into instruction memory (I memory). The remaining are the program text to be loaded into I memory. All other addresses not covered by the image are assumed to have been initialized to 0’s.
• dimage.bin: The data image (little-endian format, encoded in binary). The first four bytes show the initial value of $sp. The next four bytes indicate how many words to be loaded into data memory (D memory). The remaining are the data to be loaded into D memory, starting from address 0. The contents of all other addresses not covered by the image are assumed to have been initialized to 0’s.

Output format

For each test case, the simulator wiil generate the following two files respectively:

• snapshot.rpt: contain all register values at each cycle.
• error_dump.rpt: contain error messages.

Usage

Put the iimage.bin and dimage.bin in the working directory

• make: compile single_cycle
• make clean: clean cache and log files generated in compiling
• execute single_cycle

Reference

Reduced MIPS R3000 ISA

• R-format

R	opcode(6)	rs(5)	rt(5)	rd(5)	shamt(5)	funct(6)
add	0x00				X	0x20
sub	0x00				X	0x22
and	0x00				X	0x24
or	0x00				X	0x25
xor	0x00				X	0x26
nor	0x00				X	0x27
nand	0x00				X	0x28
slt	0x00				X	0x2A
sll	0x00	X				0x00
srl	0x00	X				0x02
sra	0x00	X				0x03
jr	0x00		X	X	X	0x08

• I Type Instruction

I	opcode(6)	rs(5)	rt(5)	immediate(16)
addi	0x08
lw	0x23
lh	0x21
lhu	0x25
lb	0x20
lbu	0x24
sw	0x2B
sh	0x29
sb	0x28
lui	0x0F	X
andi	0x0C
ori	0x0D
nori	0x0E
slti	0x0A
beq	0x04
bne	0x05

• J Type Instruction

J	opcode(6)	address(26)
jr	0x02
jal	0x03

• Special Type Instruction

S	opcode(6)	address(26)
halt	0x3F	X