nandgame/logic_unit.sv


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// nandgame logic unit

`timescale 1us/1us

`include "nandgame_types.v"

module logic_unit #(
  parameter DATA_WIDTH = 16
) (
  input [(DATA_WIDTH-1):0] X,
  input [(DATA_WIDTH-1):0] Y,
  input LogicCode operation,

  output logic [(DATA_WIDTH-1):0] RES
);

// learning: instead of this nested ternary...
// assign RES = operation == LOGIC_AND ? (X & Y) : 
//               operation == LOGIC_OR ? (X | Y) :
//               operation == LOGIC_XOR ? (X ^ Y) :
//               operation == LOGIC_NEGT ? (~X) : 0;

// ... you can do this:

always_comb begin
    case (operation)
        LOGIC_AND: RES = X & Y;
        LOGIC_OR:  RES = X | Y;
        LOGIC_XOR: RES = X ^ Y;
        LOGIC_NEGT: RES = ~X;
        default: RES = 0;
    endcase
end

endmodule