Untitled

module pipelined_carry_lookahead_adder #(parameter WIDTH = 4) (
    input clk,
    input [WIDTH-1:0] i_add1,
    input [WIDTH-1:0] i_add2,
    output [WIDTH:0] o_result
);
    wire [WIDTH:0] w_C;
    wire [WIDTH-1:0] w_G, w_P, w_SUM;
    wire [WIDTH-1:0] w_SUM_stage1, w_SUM_stage2;
    wire [WIDTH:0] w_C_stage2;

    // Stage 1: Full Adders
    genvar ii;
    generate
        for (ii = 0; ii < WIDTH; ii = ii + 1) begin
            assign w_SUM[ii] = i_add1[ii] ^ i_add2[ii] ^ w_C[ii];
        end
    endgenerate

    N_bit_register #(WIDTH) reg_stage1 (.clk(clk), .d(w_SUM), .q(w_SUM_stage1));

    // Stage 2: Generate and Propagate Terms
    genvar jj;
    generate
        for (jj = 0; jj < WIDTH; jj = jj + 1) begin
            assign w_G[jj] = i_add1[jj] & i_add2[jj];
            assign w_P[jj] = i_add1[jj] | i_add2[jj];
        end
    endgenerate

    // Stage 3: Carry Terms
    generate
        for (jj = 0; jj < WIDTH; jj = jj + 1) begin
            assign w_C[jj + 1] = w_G[jj] | (w_P[jj] & w_C[jj]);
        end
    endgenerate

    N_bit_register #(WIDTH) reg_stage2 (.clk(clk), .d(w_C[WIDTH-1:0]), .q(w_C_stage2));
    N_bit_register #(WIDTH) reg_stage3 (.clk(clk), .d(w_SUM_stage1), .q(w_SUM_stage2));

    assign w_C[0] = 1'b0; // no carry input on first adder
    assign o_result = {w_C_stage2[WIDTH], w_SUM_stage2}; // Verilog Concatenation

endmodule