module arithmeticUnit ( input [1:0] opCode, input [3:0] A, B, input CarryIN, output [3:0] add_Y, sub_Y, output CarryOUT, output overflow ); wire [3:0] addY, subY; wire CarryOUTADD, CarryOUTSUB; addition a1(.A(A), .B(B), .CarryIN(CarryIN), .Y(addY), .CarryOUT(CarryOUTADD), .overflow(overflow)); subtraction s1(.A(A), .B(B), .BorrowIN(CarryIN), .Y(subY), .BorrowOUT(CarryOUTSUB)); and add1 (add_Y[0], opCode[0], addY[0]); and add2 (add_Y[1], opCode[0], addY[1]); and add3 (add_Y[2], opCode[0], addY[2]); and add4 (add_Y[3], opCode[0], addY[3]); and sub1 (sub_Y[0], opCode[1], subY[0]); and sub2 (sub_Y[1], opCode[1], subY[1]); and sub3 (sub_Y[2], opCode[1], subY[2]); and sub4 (sub_Y[3], opCode[1], subY[3]); or or1 (CarryOUT, CarryOUTADD, CarryOUTSUB); endmodule