RosettaCodeData/Task/Four-bit-adder/SystemVerilog/four-bit-adder-1.v

34 lines
659 B
Verilog

module Half_Adder( input a, b, output s, c );
assign s = a ^ b;
assign c = a & b;
endmodule
module Full_Adder( input a, b, c_in, output s, c_out );
wire s_ha1, c_ha1, c_ha2;
Half_Adder ha1( .a(c_in), .b(a), .s(s_ha1), .c(c_ha1) );
Half_Adder ha2( .a(s_ha1), .b(b), .s(s), .c(c_ha2) );
assign c_out = c_ha1 | c_ha2;
endmodule
module Multibit_Adder(a,b,s);
parameter N = 8;
input [N-1:0] a;
input [N-1:0] b;
output [N:0] s;
wire [N:0] c;
assign c[0] = 0;
assign s[N] = c[N];
generate
genvar I;
for (I=0; I<N; ++I) Full_Adder add( .a(a[I]), .b(b[I]), .s(s[I]), .c_in(c[I]), .c_out(c[I+1]) );
endgenerate
endmodule