CSE3038-Project 2 Solved

In this project, you are required to extend the MIPS single-cycle implementation by implementing additional instructions. You will use ModelSim simulator [1] to develop and test your code. You are required to implement your assigned 6 instructions (selected from following 28 instructions). Note that your set of 6 instructions will be emailed to you or your group member.  

R-format (11): balrn, balrz, sll, srl, sllv, srlv, jmadd, jmor, jmsub, jalr, jr

I-format (13): xori , andi, ori, bneal, bgez, bgezal, bgtz, blez, bltzal, bltz, jrs, jrsal, jpc

J-format (4): baln, balz, balv, jal

 

You must design the revised single-cycle datapath and revised control units which make a processor that executes your instructions as well as the instructions implemented already in the design. After designing the new enhanced processor, you will implement it in Verilog HDL.  

Specifications of New Instructions

               Instr      Type Code                 Syntax                         Meaning

 

 

1.     xori      I-type  opcode=14      xori $rt, $rs, Label     Put the logical XOR of register $rs and the zero-                                                                                    extended immediate into register $rt.

2.     andi     I-type opcode=12        andi $rt, $rs, Label     Put the logical AND of register $rs and the zero-                                                                                    extended immediate into register $rt.  

3.     ori       I-type opcode=13        ori $rt, $rs, Label        Put the logical OR of register $rs and the zero- extended immediate into register $rt.

4.     bneal I-type opcode=45          bneal $rs, $rt, Target  if R[rs] != R[rt], branches to PC-relative address   (formed as beq & bne do), link address is stored  in register 31   

5.     bgez     I-type opcode=39       bgez    $rs, Label        if  R[rs] = 0, branch to PC-relative address (formed  

                                                                                    as beq & bne do)   

6.     bgezal  I-type opcode=35     bgezal $rs, Label        if  R[rs] = 0, branch to PC-relative address (formed

                                                                                    as beq & bne do), link address is stored in register 31.  

7.     bgtz     I-type opcode=38        bgtz     $rs, Label       if  R[rs] 0, branch to PC-relative address (formed  

                                                                                   as beq & bne do)

8.     blez      I-type opcode =6         blez     $rs, Label       if  R[rs] <= 0, branch to PC-relative address (formed  

                                                                                   as beq & bne do)   

9.     bltzal I-type opcode=34          bltzal $rs, Label          if  R[rs] < 0,  branch to to PC-relative address (formed                                                                                     as beq & bne do), link address is stored in register 31.  

10.  bltz      I-type  opcode=1         bltz $rs, $rt, Target     if R[rs] < 0, branches to PC-relative address (formed as  

                                                                                                   beq & bne do)   

 

11.  balrz R-type funct=22             balrz $rs, $rd   if  Status [Z] = 1, branches to address found in register  

                                                                                    $rs link address is stored in $rd (which defaults to 31)

12.  balrn R-type funct=23             balrn $rs, $rd   if  Status [N] = 1, branches to address found in register     

                                                                                    $rs link address is stored in $rd (which defaults to 31)

13. jmadd R-type funct=32
jmadd $rs,$rt               jumps to address found in memory [$rs+$rt],                         link address     is stored in $31
14. jmor    R-type funct=37  
jmor $rs,$rt                 jumps to address found in memory [$rs|$rt],                          link address     is stored in $31
15. jmsub R-type funct=34
jmsub $rs,$rt               jumps to address found in memory [$rs-$rt], link address
                               
                                    is stored in $31
16. jalr       R-type func=9  
jalr $rs, $rd     Unconditionally jump to the address found    in register $rs, link address is stored in $rd.  
17. jr         R-type func=8             jr $rs                            Unconditionally jump to the address found in   
                                                                                    register $rs  

       18. balv     J-type opcode=33        balv Target              if Status [V] = 1, branches to pseudo-direct address   

(formed as jal does), link address is stored in register 31 19. balz    J-type opcode=26       balz Target             if Status [Z] = 1, branches to pseudo-direct address  

                                                                                    (formed as jal does), link address is stored in register 31

20.  baln     J-type opcode=27       baln Target                  if Status [N] = 1, branches to pseudo-direct address  

                                                                                     (formed as jal does), link address is stored in register 31

21.  jal        J-type opcode=3         jal Target         jump to pseudo-direct address (formed as j does),                                                                              link address is stored in register 31.  

22.  jpc       I-type opcode=30        jpc Target                    jumps to PC-relative address (formed as beq and bne do)                                                                            link address     is stored in $rt (which defaults to 31)

23.  jrs        I-type opcode=18        jrs   $rs                        jumps to address found in memory where the memory                                                                                      address is written in register $rs.  

24.  jrsal     I-type opcode=19        jrsal   $rs                     jumps to address found in memory where the memory                                                                              address is written in register $rs and link address is stored in memory (DataMemory[$rs]).

25.  sll        R-type func=0             sll $rd, $rt, shamt       shift register $rt to left by shift amount (shamt) and store                                                                                      the result in register $rd.  

26.  srl        R-type func=2             srl $rd, $rt, shamt        shift register $rt to right by shift amount (shamt) and                                                                                      store the result in register $rd.  

27.  sllv      R-type func=4             sllv $rd, $rt, $rs        shift register $rt to left by the value in register $rs, and                                                                                              store the result in register $rd.     

28.  srlv      R-type func=6             srlv $rd, $rt, $rs         shift register $rt to right by the value in register $rs, and                                                                                            store the result in register $rd.                                                 

                                                                                     

Status Register

Some of the conditional branches test the Z and N bits in the Status register. So the MIPS datapath will need to have a Status register, with the following 3 bits: Z (if the ALU result is zero) , N (if the ALU result is negative) or V (if the ALU result causes overflow). The Status register will be loaded with the ALU results each clock cycle.