Implement CPU Controller

Controller.sv

@@ -0,0 +1,71 @@
+`default_nettype none
+
+module Controller(
+  input var logic clock,
+  input var logic reset,
+  input var logic[7:0] databus,
+
+  output var logic[1:0] opcode,
+  output var logic regs_set,
+  output var logic[2:0] regs_savesel,
+  output var logic[2:0] regs_loadsel,
+  output var logic[2:0] alu_opc,
+  output var logic[2:0] cond_opc,
+  output var logic pc_set
+);
+
+  var logic[5:0] arg;
+  var logic[2:0] arg0;
+  var logic[2:0] arg1;
+  assign opcode = databus[7:6];
+  assign arg = databus[5:0];
+  assign arg0 = databus[2:0];
+  assign arg1 = databus[5:3];
+
+  always @(posedge clock or posedge reset) if (reset) begin
+      regs_set = 1'b0;
+      regs_savesel = 3'b000;
+      regs_loadsel = 3'b000;
+      alu_opc = 3'b000;
+      cond_opc = 3'b000;
+      pc_set = 1'b0;
+  end else case (opcode)
+    2'b00: begin
+      // Load
+      regs_set = 1'b1;
+      regs_savesel = 3'b000; // Always save to reg0
+      regs_loadsel = 3'b000;
+      alu_opc = 3'b000;
+      cond_opc = 3'b000;
+      pc_set = 1'b0;
+    end
+    2'b01: begin
+      // ALU
+      regs_set = 1'b1;
+      regs_savesel = 3'b011; // Always save to reg3
+      regs_loadsel = 3'b000;
+      alu_opc = arg0;
+      cond_opc = 3'b000;
+      pc_set = 1'b0;
+    end
+    2'b10: begin
+      // Copy
+      regs_set = 1'b1;
+      regs_savesel = arg0;
+      regs_loadsel = arg1;
+      alu_opc = 3'b000;
+      cond_opc = 3'b000;
+      pc_set = 1'b0;
+    end
+    2'b11: begin
+      // Cond
+      regs_set = 1'b0;
+      regs_savesel = 3'b000;
+      regs_loadsel = 3'b000;
+      alu_opc = 3'b000;
+      cond_opc = arg0;
+      pc_set = 1'b1;
+    end
+  endcase
+
+endmodule