// Via http://www.edaplayground.com/s/6/591 // stackoverflow 20556634 // http://stackoverflow.com/questions/20556634/how-can-i-iteratively-create-buses-of-parameterized-size-to-connect-modules-also // Code your design here `define macro_args `define indexed_part_select module Multiplier_flat #(parameter M = 4, parameter N = 4)( input [M-1:0] A, //Input A, size M input [N-1:0] B, //Input B, size N output [M+N-1:0] P ); //Output P (product), size M+N /* Calculate LSB using Wolfram Alpha N==3 : http://www.wolframalpha.com/input/?i=0%2C+4%2C+9%2C+15%2C+... N==4 : http://www.wolframalpha.com/input/?i=0%2C+5%2C+11%2C+18%2C+26%2C+35%2C+... N==5 : http://www.wolframalpha.com/input/?i=0%2C+6%2C+13%2C+21%2C+30%2C+... */ `ifdef macro_args // initial \$display("Use Macro Args"); `define calc_pp_lsb(n) (((n)-1)*((n)+2*M)/2) //`define calc_pp_msb(n) (`calc_pp_lsb(n+1)-1) `define calc_pp_msb(n) ((n**2+(2*M+1)*n-2)/2) //`define calc_range(n) `calc_pp_msb(n):`calc_pp_lsb(n) `define calc_pp_range(n) `calc_pp_lsb(n) +: (M+n) wire [`calc_pp_msb(N):0] PP; assign PP[`calc_pp_range(1)] = { 1'b0 , { A & {M{B[0]}} } }; assign P = PP[`calc_pp_range(N)]; `elsif indexed_part_select // initial \$display("Use Indexed Part Select"); localparam MSB = (N**2+(2*M+1)*N-2)/2; wire [MSB:0] PP; assign PP[M:0] = { 1'b0 , { A & {M{B[0]}} } }; assign P = PP[MSB -: M+N]; `else // initial \$display("Use Worst Case"); localparam MSB = (N**2+(2*M+1)*N-2)/2; wire [MSB:0] PP; assign PP[M:0] = { 1'b0 , { A & {M{B[0]}} } }; assign P = PP[MSB : MSB+1-M-N]; `endif genvar i; generate for (i=1; i < N; i=i+1) begin: addPartialProduct wire [M+i-1:0] gA,gB,gS; wire Cout; assign gA = { A & {M{B[i]}} , {i{1'b0}} }; `ifdef macro_args assign gB = PP[`calc_pp_range(i)]; assign PP[`calc_pp_range(i+1)] = {Cout,gS}; `elsif indexed_part_select assign gB = PP[(i-1)*(i+2*M)/2 +: M+i]; assign PP[i*((i+1)+2*M)/2 +: M+i+1] = {Cout,gS}; `else localparam LSB = (i-1)*(i+2*M)/2; localparam MSB = (i**2+(2*M+1)*i-2)/2; localparam MSB2 = ((i+1)**2+(2*M+1)*(i+1)-2)/2; assign gB = PP[MSB : LSB]; assign PP[ MSB2 : MSB+1] = {Cout,gS}; `endif RippleCarryAdder#(M+i) adder( .A(gA), .B(gB), .S(gS), .Cin (1'b0), .Cout(Cout) ); end endgenerate `ifdef macro_args // Cleanup global space `undef calc_pp_range `undef calc_pp_msb `undef calc_pp_lsb `endif endmodule module Multiplier_2D #(parameter M = 4, parameter N = 4)( input [M-1:0] A, //Input A, size M input [N-1:0] B, //Input B, size N output [M+N-1:0] P ); //Output P (product), size M+N wire [M+N-1:0] PP [N-1:0]; // Note: bits PP[0][M+N-1:M+1] are never used. Unused bits are optimized out during synthesis //assign PP[0][M:0] = { {1'b0} , { A & {M{B[0]}} } }; //assign PP[0][M+N-1:M+1] = {(N-1){1'b0}}; // uncomment to make probing readable assign PP[0] = { {N{1'b0}} , { A & {M{B[0]}} } }; assign P = PP[N-1]; genvar i; generate for (i=1; i < N; i=i+1) begin: addPartialProduct wire [M+i-1:0] gA,gB,gS; wire Cout; assign gA = { A & {M{B[i]}} , {i{1'b0}} }; assign gB = PP[i-1][M+i-1:0]; //assign PP[i][M+i:0] = {Cout,gS}; //if (i+1