Initial commit. Working CPU!

cpu.sv

@@ -0,0 +1,89 @@
+module cpu 	(input logic clk, reset,
+			 input logic prog,
+			 input logic[31:0] pinst,
+			 input logic[7:0] paddr,
+			 output logic [31:0] disp);
+	logic [7:0] pc;
+	logic [7:0] pc_next, pc_compute;
+	logic [31:0] inst;
+	logic [5:0] op;
+	logic [2:0] rd, rs, rt;
+	logic [31:0] rd_val, rs_val, rt_val;
+	logic [15:0] const_val;
+	logic [31:0] const_extend;
+	logic [31:0] cpu_disp;
+	logic [31:0] reg_alu_out, const_alu_out;
+	logic should_jump, should_write, use_const;
+	
+	assign op = inst[31:26];
+	assign rd = inst[25:23];
+	assign rs = inst[22:20];
+	assign rt = inst[19:17];
+	assign const_val = inst[15:0];
+	
+	assign should_write = inst[31];
+	assign use_const = inst[30];
+	assign should_jump = inst[29];
+	
+	assign const_extend = const_val;
+	
+	registers #(32) regs(
+		.raddr1(rs),
+		.raddr2(rt),
+		.waddr(rd),
+		.in(rd_val),
+		.wen(should_write),
+		.clk(clk),
+		.reset(reset),
+		.out1(rs_val),
+		.out2(rt_val));
+	
+	memory #(32) insts(
+		.raddr(pc),
+		.waddr(paddr),
+		.wen(prog),
+		.in(pinst),
+		.clk(clk),
+		.out(inst),
+		.reset(reset));
+		
+	alu #(32) reg_alu(
+		.left(rs_val),
+		.right(rt_val),
+		.op(inst[28:26]),
+		.out(reg_alu_out));
+		
+	alu #(32) const_alu(
+		.left(rs_val),
+		.right(const_extend),
+		.op(inst[28:26]),
+		.out(const_alu_out));
+		
+	mux2 #(32) out_mux(
+		.left(reg_alu_out),
+		.right(const_alu_out),
+		.select(use_const),
+		.out(rd_val));
+		
+	assign pc_compute = rt_val + const_val;
+
+	mux2 #(8) pc_mux(
+		.left(pc + 1),
+		.right(pc_compute),
+		.select(should_jump & (inst[28] | (inst[26] ^ (rs_val == 0)))),
+		.out(pc_next));
+	
+	always_ff@(posedge clk) 
+		if(reset) begin
+			pc <= 0;
+			cpu_disp <= 0;
+		end else if(!prog) begin
+			case(op)
+				6'b0000000: cpu_disp <= rs_val;
+			endcase
+			pc <= pc_next;
+		end
+	
+	assign disp = cpu_disp;
+	
+endmodule