Somado Completo

// -------------------------
// Somador Completo para um bit
// Output carryOut("vai um")
// Output soma(resultado da soma)
// inputs a,b,CarryIn("Vem um")
// -------------------------
module fullAdder ( output carryOut,output soma,input a,input b,input carryIn );
wire nota;
wire notb;
wire notcarryIn;
wire and1;
wire and2;
wire and3;
wire and4;
wire and5;
wire and6;
wire and7;
wire and8;
not notA(nota,a);
not notB(notb,b);
not notcarry(notcarryIn,carryIn);
and and1(and1,nota,notb,carryIn);
and and2(and2,nota,b,notcarryIn);
and and3(and3,a,notb,notcarryIn);
and and4(and4,a,b,carryIn);
or or1(soma,and1,and2,and3,and4);
and and5(and5,nota,b,carryIn);
and and6(and6,a,notb,notcarryIn);
and and7(and7,a,b,notcarryIn);
and and8(and8,a,b,carryIn);
or or2(carryOut,a,b,carryIn);
endmodule // fullAdder
module test_fullAdder;
// ------------------------- definir dados
reg [3:0] a;
reg [3:0] b;
wire [3:0] carryOut; // “vai-um”
wire [4:0] soma;
fullAdder FA0 ( carryOut[0], soma[0], a[0], b[0],1'b0);
fullAdder FA1 ( carryOut[1], soma[1], a[1], b[1],carryOut[0]);
fullAdder FA2 ( carryOut[2], soma[2], a[2], b[2],carryOut[1]);
fullAdder FA3 ( carryOut[3], soma[3], a[3], b[3],carryOut[2]);
assign soma[4]=carryOut[3];
// ------------------------- parte principal
initial begin
$display("   a    b  soma  vai(carry)");
$monitor("%4b %4b %4b %4b", a, b, soma, carryOut);
a = 4'b0000; b = 4'b0000;
#1 a = 4'b0001; b = 4'b0001;
#1 a = 4'b0010; b = 4'b0010;
#1 a = 4'b0011; b = 4'b0011;
end
endmodule // test_fullAdder