Utilizing the ALU in Lab2 to implement a simple single cycle CPU. CPU is the most important unit in computer system. Reading the document carefully and do the Lab, you will have elementary knowledge of CPU.

2. Demands

1. Please use iverilog
2. Simple_Single_CPU.v, Adder.v, ALU.v, ALU_Ctrl.v, Decoder.v,

Instr_Memory.v, Mux2to1.v, Mux3to1.v, Program_Counter.v, Reg_File.v, Shifter.v, Sign_Extend.v, Zero_Filled.v, and TestBench.v are supplied. Please use these modules to accomplish the design of your CPU and dont change the file name.

Instruction set: the following instructions have to running in your designed CPU (80pts.)

Shifter

The block diagram of the shifter to be implemented is shown:

Shift.v contains the following inputs and outputs:

• sftSrc: A 32-bit input data, is the source data of the shifter.
• leftRight: A 1-bit input control signal. When it is set to 1, the shifter perform logical left shift; else, does logical right shift.
• shamt: A 5-bit input data, represents the number of bit positions to be shifted.
• result: A 32-bit output data, which represents the shifting result of the shifter.

SRL Rd, Rt, shamt (Rs is ignored for SRL)

Shift register Rt right by the distance indicated by immediate shamt

4. Bonus

Implement SLLV (Shift left logical variable) and SRLV (Shift right logical variable) instructions. You can add new module or control signal in this advanced design.

SRLV Rd, Rt, Rs

Shift register Rt right by the distance indicated by the register Rs

5. Test Bench

In Lab3, three test data (binary code), stored in CO_P3_test_data1.txt ~

CO_P3_test_data3.txt, are provided. The default test data is the first one. If you would like to use second test data, modify line 75 in the file TestBench.v as follows: $readmemb(CO_P3_test_data1.txt, cpu.IM.Instr_Mem);

The Assembly codes of the test data are given as follows:

After the simulation of TestBench, you will get the file CO_P3_result.txt. You can verify the result. If your design passes the test data, the following words would show in the Transcript windows.