Instruction Set Architecture

ISA (Instruction Set Architecture) for MIPS 32 refers to the set of instructions that the MIPS (Microprocessor without Interlocked Pipeline Stages) architecture supports for 32-bit processing.

• Instruction Formats: MIPS 32 instructions are typically 32 bits long and can be categorized into three main formats: R-type, I-type, and J-type. R-type instructions are used for arithmetic and logical operations, I-type instructions for immediate values "adding constant to register", and J-type instructions for jump operations.

• Registers: MIPS 32 architecture has 32 general-purpose registers, labeled as $0 to $31. Register $0 is hardwired to zero and has special properties.

• Data Types: MIPS 32 supports 32-bit data types for integers, but not supporing floating-point numbers.

Microprocessor without Interlocked Pipeline Stages

-Top level schematic for mips.

- Detailed schematic for mips.

Objective

• Set of predefined MIPS instructions.
• Design a simplified MIPS processor in Verilog.
• Develop a testbench plan to verify the functionality and performance of the processor.

Tools and Technologies

• Hardware Description Language (HDL) : Verilog
• Simulation and Verification : QuestaSim
• Synthesis Tool : Vivado
• Hardware : FPGA xilinx spartan 6 board

Project Phases

1. Requirements Analysis
2. Design Specification
3. Implementation
4. Testbench Design
5. Verification

Phase 1: Requirements Analysis

• Task 1.1 : Identify the subset of MIPS instructions to be implemented (ADD, SUB, LW, SW, .. ).
• Task 1.2 : Determine the required processor components (ALU, Register File, Control Unit, .. ).
• Task 1.3 : Establish performance goals and constraints (clock speed , timing constraints, ..).

Phase 2: Design Specification

• Task 2.1 : Define the architecture of the MIPS processor, including the datapath and control path.
• Task 2.2 : Create detailed specifications for each processor component.
• Task 2.3 : Design the instruction set architecture (ISA) and encoding scheme.

Phase 3: Implementation

• Task 3.1 : Implement the processor components in Verilog (ALU, Register File, .. ).
• Task 3.2 : Develop the control unit.
• Task 3.3 : Integrate the components to form the complete MIPS processor.

Phase 4: Testbench Design

• Task 4.1 : Develop a test plan outlining the tests to be performed, including unit tests for components and integration tests for the full processor.
• Task 4.2 : Write testbench code in Verilog to implement the test plan.
• Task 4.3 : Create test vectors and stimulus for each test case.

Phase 5: Verification

• Task 5.1 : Simulate the individual components using the testbench code.
• Task 5.2 : Perform integration testing on the full processor.
• Task 5.3 : Analyze the simulation results and verify against the specifications.

References

• Digital Logic And Computer Design By M. Morris Mano
• Computer Organization and Design RISC-V edition written by David A. Patterson and John L. Hennessy
• Digital Design and Computer Architecture Book by David Harris