CONTROL_UNIT.v.bak

module CONTROL_UNIT
(
    input CLOCK, FLAG_Z,
    input [7:0] INSTRUCTION,
    output reg FETCH, FINISH = 0,
    output reg [2:0] REG_IN_B_BUS,
    output reg [2:0] ALU_OP,
    output reg [12:0] SELECTORS
    
);

    localparam
    FETCH1 = 6'd0, FETCH2 = 6'd1, FETCH3 = 6'd2, FETCH4 = 6'd57,
    CLAC1 = 6'd3, MVACAR1 = 6'd59, STAC1 = 6'd4, WRITE = 6'd53,
    MVACRI1 = 6'd6, MVACRII1 = 6'd7, MVACRIII1 = 6'd8, MVACR1 = 6'd9,
    MVRIAC1 = 6'd10, MVRIIAC1 = 6'd11, MVRIIIAC1 = 6'd12, MVRAC1 = 6'd13,
    INAC1 = 6'd14, INCR1 = 6'd40, INCR2 = 6'd41, INCR3 = 6'd42, 
    LDAC1 = 6'd15, LDAC2 = 6'd16, LDAC3 = 6'd56,
    SUB1 = 6'd17, ADD1 = 6'd19, DIV21 = 6'd20, DECAC1 = 6'd18, BYTESHIFT1 = 6'd21,
    JUMPNZ1 = 6'd22, JUMPNZY1 = 6'd23, JUMPNZN1 = 6'd24, JUMPNZN2 = 6'd25,
    JUMPNZN3 = 6'd26, JUMPNZNSKIP = 6'd55,
    ADDM1 = 6'd27, ADDM2 = 6'd28, ADDMPC = 6'd54,
    NOP = 6'd58, END = 6'd60;
    
    reg [5:0] CONTROL_COMMAND;
    reg [5:0] NEXT_COMMAND = FETCH1;
    
    always @ (negedge CLOCK) CONTROL_COMMAND <= NEXT_COMMAND;
    
    always @ (CONTROL_COMMAND or FLAG_Z or INSTRUCTION)
        case(CONTROL_COMMAND)
            FETCH1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd7;
                    ALU_OP <= 3'd2;
                    SELECTORS <= 13'b0_0000_0000_0000;
                    NEXT_COMMAND <= FETCH2;
                end

            FETCH2:
                begin
                    FETCH <= 1;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd7;
                    ALU_OP <= 3'd2;
                    SELECTORS <= 13'b0_0000_0000_0000;
                    NEXT_COMMAND <= FETCH3;
                end
            
            FETCH3:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd2;
                    SELECTORS <= 13'b1_0000_0000_0000;
                    NEXT_COMMAND <= FETCH4;
                end
            
            FETCH4:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd2;
                    SELECTORS <= 13'b0_0000_0000_0000;
                    NEXT_COMMAND <= INSTRUCTION[5:0];
                end
            
            CLAC1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd3;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= FETCH1;
                end
            
            MVACAR1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd6;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_1000_0000;
                    NEXT_COMMAND <= FETCH1;
                end
            
            STAC1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd6;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_0000_0001;
                    NEXT_COMMAND <= WRITE;
                end
            
            WRITE:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd6;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_0000_0001;
                    NEXT_COMMAND <= FETCH1;
                end
            
            MVACRI1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd6;
                    ALU_OP <=3'd0;
                    SELECTORS <= 13'b0_0000_0010_0000;
                    NEXT_COMMAND <= FETCH1;
                end
            
            MVACRII1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd6;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_0001_0000;
                    NEXT_COMMAND <= FETCH1;
                end
            
            MVACRIII1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd6;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_0000_1000;
                    NEXT_COMMAND <= FETCH1;
                end
            
            MVACR1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <=3'd6;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_0000_0100;
                    NEXT_COMMAND <= FETCH1;
                end
            
            MVRIAC1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd2;
                    ALU_OP <= 3'd2;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= FETCH1;
                end
            
            MVRIIAC1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd3;
                    ALU_OP <= 3'd2;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= FETCH1;
                end
            
            MVRIIIAC1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd4;
                    ALU_OP <= 3'd2;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= FETCH1;
                end
            
            MVRAC1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd5;
                    ALU_OP <= 3'd2;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= FETCH1;
                end
            
            INAC1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0001_0000_0000;
                    NEXT_COMMAND <= FETCH1;
                end
            
            INCR1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_1000_0000_0000;
                    NEXT_COMMAND <= FETCH1;
                end
            
            INCR2:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0100_0000_0000;
                    NEXT_COMMAND <= FETCH1;
                end
                
            INCR3:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0010_0000_0000;
                    NEXT_COMMAND <= FETCH1;
                end
            
            LDAC1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd6;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_1000_0000;
                    NEXT_COMMAND <= LDAC2;
                end
            
            LDAC2:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_0000_0000;
                    NEXT_COMMAND <= LDAC3;
                end
            
            LDAC3:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd2;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= FETCH1;
                end
            
            SUB1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd5;
                    ALU_OP <= 3'd1;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= FETCH1;
                end
            
            DECAC1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd4;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= FETCH1;
                end
            
            ADD1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd5;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= FETCH1;
                end
            
            DIV21:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd6;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= FETCH1;
                end
            
            BYTESHIFT1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd5;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= FETCH1;
                end
            
            JUMPNZ1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd2;
                    SELECTORS <= 13'b0_0000_0000_0000;
                    if (FLAG_Z) NEXT_COMMAND <= JUMPNZY1;
                    else NEXT_COMMAND <= JUMPNZN1;
                end
            
            JUMPNZY1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd2;
                    SELECTORS <= 13'b1_0000_0000_0000;
                    NEXT_COMMAND <= FETCH1;
                end
            
            JUMPNZN1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd7;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_0000_0000;
                    NEXT_COMMAND <= JUMPNZN2;
                end
            
            JUMPNZN2:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd7;
                    ALU_OP <= 3'd2;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= JUMPNZN3;
                end

            JUMPNZN3:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd6;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_0100_0000;
                    NEXT_COMMAND <= FETCH1;
                end

            ADDM1:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd1;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_0000_0000;
                    NEXT_COMMAND <= ADDM2;
                end

            ADDM2:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd7;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_0000_0010;
                    NEXT_COMMAND <= ADDMPC;
                end

            ADDMPC:
                begin
                    FETCH <= 0;
                    FINISH <= 0;
                    REG_IN_B_BUS <= 3'd3;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b1_0000_0000_0000;
                    NEXT_COMMAND <= FETCH1;
                end

            NOP:
                begin
                FETCH <= 0;
                FINISH <= 0;
                REG_IN_B_BUS <= 3'd0;
                ALU_OP <= 3'd0;
                SELECTORS <= 13'b0_0000_0000_0000;
                NEXT_COMMAND <= FETCH1;
                end

            END:
                begin
                    FETCH <= 0;
                    FINISH <= 1;
                    REG_IN_B_BUS <= 3'd0;
                    ALU_OP <= 3'd0;
                    SELECTORS <= 13'b0_0000_0000_0000;
                    NEXT_COMMAND <= END;
                end

        endcase

endmodule