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wip(<General Control Module>): #174

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319 changes: 319 additions & 0 deletions rtl/General_Control_Module.sv
Original file line number Diff line number Diff line change
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module GENERAL_CONTROL_MODULE(
input clk,
input rstn,
input ins [31:0],

output pc_en,
output immode[2:0],
output wbe,
output branch_occr[1:0],
output a_sel[1:0],
output b_sel[1:0],
output alu_mode[5:0],
output branch_cond[1:0],
output data_mode[1:0],
output dcache_rw,
output dcache_en,
output wbs[2:0]
);

logic ID_ins[31:0], EX_ins[31:0], MEM_ins[31:0], WB_ins[31:0];
logic hazard;

//Opcodes
parameter
R = 7'b0110011,
I_1 = 7'b0010011,
I_2 = 7'b0000011,
I_3 = 7'b1100111,
S = 7'b0100011,
B = 7'b1100011,
U1 = 7'b0110111,
U2 = 7'b0010111,
J = 7'b1101111,
NOP1 = 7'b0000000,
NOP2 = 7'b0001111,
NOP3 = 7'b1110011;


always_comb //immmode selection
begin
case (ins[6:0])
R: immode = 3'd0;
I_1, I_2, I_3: immode = 3'd1;
S: immode = 3'd2;
B: immode = 3'd3;
U1, U2: immode = 3'd4;
J: immode = 3'd5;
NOP1, NOP2, NOP3: immode = 3'd0;
default: immode = 3'd0;
endcase
end

always_ff @(posedge clk or negedge rstn)
begin
if (!rstn) begin //asych active low reset
ID_ins <= 32'd0;
EX_ins <= 32'd0;
MEM_ins <= 32'd0;
WB_ins <= 32'd0;
hazard <= 1'b0; // Initialize hazard to 0 on reset
end

else if (hazard) begin
ID_ins <= 32'd0; // NOP
end

else begin
ID_ins <= ins;
EX_ins <= ID_ins;
MEM_ins <= EX_ins;
WB_ins <= MEM_ins;
end
end

// Hazard detection
always_comb
begin
pc_en = !hazard;

if ((ins[6:0] == I_3 || ins[6:0] == B || ins[6:0] == J) && !hazard)
begin
hazard = 1;
end

else if (ins[6:0] == R || ins[6:0] == I_1 || ins[6:0] == I_2 || ins[6:0]== I_3 || ins[6:0] == S || ins[6:0] == B || ins[6:0] == U1|| ins[6:0] == U2 || ins[6:0] == J)
begin
if ((ID_ins[6:0] == R || ID_ins[6:0] == I_1 || ID_ins[6:0] == I_2 || ID_ins[6:0] == I_3 || ID_ins[6:0] == U1 || ID_ins[6:0] == U2 || ID_ins[6:0] == J) &&
((ID_ins[11:7] == ins[11:7]) || (ID_ins[11:7] == ins[24:20]) || (ID_ins[11:7] == ins[19:15])) && (ID_ins[11:7] != 0))
begin
hazard = 1;
end
if ((EX_ins[6:0] == R ||EX_ins[6:0] == I_1 || EX_ins[6:0] == I_2 || EX_ins[6:0] == I_3 || EX_ins[6:0] == U1 || EX_ins[6:0] == U2 || EX_ins[6:0] == J) &&
((EX_ins[11:7] == ins[11:7]) || (EX_ins[11:7] == ins[24:20]) || (EX_ins[11:7] == ins[19:15])) && (EX_ins[11:7] != 0))
begin
hazard = 1;
end
if ((MEM_ins[6:0] == R || MEM_ins[6:0] == I_1 ||MEM_ins[6:0] == I_2 || MEM_ins[6:0] == I_3 || MEM_ins[6:0] == U1 || MEM_ins[6:0] == U2 || MEM_ins[6:0] == J) &&
((MEM_ins[11:7] == ins[11:7]) || (MEM_ins[11:7] == ins[24:20]) || (MEM_ins[11:7] == ins[19:15])) && (MEM_ins[11:7] != 0))
begin
hazard = 1;
end
if ((WB_ins[6:0] == R || WB_ins[6:0] == I_1 || WB_ins[6:0] == I_2 ||WB_ins[6:0] == I_3 || WB_ins[6:0] == U1 || WB_ins[6:0] == U2|| WB_ins[6:0] == J)&&
((WB_ins[11:7] == ins[11:7]) || (WB_ins[11:7] == ins[24:20]) ||(WB_ins[11:7] == ins[19:15])) && (WB_ins[11:7] != 0))
begin
hazard = 1;
end
end
else
begin
hazard = 0;
end
end

// output assignmetns
always_comb
begin
// Decode ID_ins
case (ID_ins[6:0])
R: begin
addr_mode = 1'b0;
branch_occr = 2'b00;
a_sel = 2'b00;
b_sel = 2'b00;
end
I_1: begin
addr_mode = 1'b0;
branch_occr = 2'b00;
a_sel = 2'b00;
b_sel = 2'b01;
end
I_2: begin
addr_mode = 1'b0;
branch_occr = 2'b00;
a_sel = 2'b00;
b_sel = 2'b00;
end
I_3: begin
addr_mode = 1'b1;
branch_occr = 2'b01;
a_sel = 2'b01;
b_sel = 2'b10;
end
S: begin
addr_mode = 1'b1;
branch_occr = 2'b00;
a_sel = 2'b00;
b_sel = 2'b00;
end
B: begin
addr_mode = 1'b0;
branch_occr = 2'b10;
a_sel = 2'b00;
b_sel = 2'b00;
end
U1, U2: begin
addr_mode = 1'b0;
branch_occr = 2'b00;
a_sel = ID_ins[5:4];
b_sel = 2'b11;
end
J: begin
addr_mode = 1'b0;
branch_occr = 2'b01;
a_sel = 2'b01;
b_sel = 2'b10;
end
NOP1, NOP2, NOP3: begin
addr_mode = 1'b0;
branch_occr = 2'b00;
a_sel = 2'b00;
b_sel = 2'b00;
end
endcase

// decode ex_ins
case (EX_ins[6:0])
R: begin
alu_mode = {EX_ins[31:25], EX_ins[14:12]};
branch_cond = 2'b00;
end
I_1: begin
alu_mode = (EX_ins[14:12] == 3'b101) ? {EX_ins[31:25], EX_ins[14:12]} : {3'b000, EX_ins[14:12]};
branch_cond =2'b00;
end
I_2: begin
alu_mode = 6'b000000;
branch_cond =2'b00;
end
I_3: begin
alu_mode = 6'b000000;
branch_cond =2'b11;
end
S: begin
alu_mode = 6'b000000;
branch_cond =2'b00;
end
B: begin
case(EX_ins[14:12])
3'b100, 3'b101: alu_mode =6'b000010;
3'b110, 3'b111: alu_mode =6'b000011;
default: alu_mode = 6'b100000;
endcase
branch_cond = (EX_ins[14:12] == 3'b001 || EX_ins[14:12] == 3'b100 || EX_ins[14:12] == 3'b110) ? 2'b01 : 2'b10;
end
U1, U2, J: begin
alu_mode = 6'b000000;
branch_cond = 2'b00;
end
NOP1, NOP2, NOP3: begin
alu_mode = 6'b000000;
branch_cond = 2'b00;
end
endcase

// Decode MEM_ins
case (MEM_ins[6:0])
R: begin
data_mode = 2'b00;
dcache_rw = 1'b0;
dcache_en = 1'b0;
end
I_1: begin
data_mode = 2'b00;
dcache_rw = 1'b0;
dcache_en = 1'b0;
end
I_2: begin
data_mode = 2'b00;
dcache_rw = 1'b0;
dcache_en = 1'b1;
end
I_3: begin
data_mode = 2'b00;
dcache_rw = 1'b0;
dcache_en = 1'b0;
end
S: begin
data_mode = MEM_ins[14:12];
dcache_rw = 1'b1;
dcache_en = 1'b1;
end
B: begin
data_mode = 2'b00;
dcache_rw = 1'b0;
dcache_en = 1'b0;
end
U1, U2: begin
data_mode = 2'b00;
dcache_rw = 1'b0;
dcache_en = 1'b0;
end
J: begin
data_mode = 2'b00;
dcache_rw = 1'b0;
dcache_en = 1'b0;
end
NOP1, NOP2, NOP3: begin
data_mode = 2'b00;
dcache_rw = 1'b0;
dcache_en = 1'b0;
end
endcase

// Decode WB_ins
case (WB_ins[6:0])
R: begin
wbs =3'b011;
wbe = 1'b1;
end
I_1: begin
wbs = 3'b011;
wbe = 1'b1;
end
I_2: begin
wbs = WB_ins[14:12];
wbe = 1'b1;
end
I_3: begin
wbs = 3'b011;
wbe = 1'b1;
end
S:
begin
wbs = 3'b000;
wbe = 1'b0;
end
B:
begin
wbs = 3'b000;
wbe = 1'b0;
end
U1:begin
wbs = 3'b011;
wbe = 1'b1;
end
U2:begin
wbs = 3'b011;
wbe = 1'b1;
end
J:begin
wbs = 3'b011;
wbe = 1'b1;
end
NOP1:begin
wbs = 3'b000;
wbe = 1'b0;
end
NOP2:begin
wbs= 3'b000;
wbe = 1'b0;
end
NOP3:begin
wbs = 3'b000;
wbe =1'b0;
end
endcase

end
endmodule