CIC_pretest

module SET ( clk , rst, en, central, radius, mode, busy, valid, candidate );

input clk, rst;
input en;
input [23:0] central; // [23:20] Xa [19:16] Ya ; [15:12] Xb [11:8] Yb ;
                             // remain the rest of it
input [11:0] radius;  // [11:8] ra ; [7:4] rb ; remain the rest of it
input [1:0] mode;

output reg busy;    //high > busy
output reg valid;   //high > output
output [7:0] candidate;

reg [7:0] candidate_tmp,candidate_tmp1,candidate_tmp2;
reg [3:0]cnt_x,cnt_y;
reg [7:0]X_ptr,Y_ptr;
reg [9:0]r;

assign  candidate[7:0] = candidate_tmp[7:0];

/* To run all the points */
always@(posedge clk or posedge rst)
begin
    if(rst)
    begin
        cnt_x <= 4'h1;
        cnt_y <= 4'h1;
        busy <= 1'b0;
        valid <= 1'b0;
    end
    else if(en)
    begin
        busy <= 1'b1;
        valid <= 1'b0;
        cnt_x <= 4'h1;
        cnt_y <= 4'h1;
    end
    else
    begin
        if(cnt_x == 4'h8 && cnt_y == 4'h8)
        begin
                busy <= 1'b0;
                valid <= 1'b1;
                cnt_x <= 4'h1;
                cnt_y <= 4'h1;
        end

        else if(cnt_x == 4'h8)
        begin
            cnt_x <= 4'h1;
            cnt_y <= cnt_y + 1;
        end

        else if(cnt_y == 4'h8)
        begin
            cnt_x <= cnt_x + 1;
        end

        else
            cnt_x <= cnt_x + 1;
    end
end

/* Modes */
always@(posedge clk or posedge rst)
begin
    if(rst)
    begin
        candidate_tmp <= 8'b0;
    end
    else if(en)
    begin
        candidate_tmp <= 8'b0;
        candidate_tmp1 <= 8'b0;
        candidate_tmp2 <= 8'b0;
    //A
        X_ptr[7:4] <=  central[23:20];
        Y_ptr[7:4] <=  central[19:16];
        r[9:5] <= radius[11:8];
    //B
        X_ptr[3:0] <=  central[15:12];
        Y_ptr[3:0] <=  central[11:8];
        r[4:0] <= radius[7:4];
    end
    else
    begin
        case(mode)
            2'b00:begin //set A and set B
                if( ((X_ptr[7:4]*X_ptr[7:4]-2*X_ptr[7:4]*cnt_x[3:0]+cnt_x[3:0]*cnt_x[3:0])
                    + (Y_ptr[7:4]*Y_ptr[7:4]+cnt_y[3:0]*cnt_y[3:0]-2*cnt_y[3:0]*Y_ptr[7:4])) <= (r[9:5]*r[9:5]) )
                    candidate_tmp <= candidate_tmp+1;
            end
                // Use a2-2ab+b2 to replace (a-b)2 to avoid negative situation

            2'b01:begin //set A & B
                if( (((
                 (X_ptr[7:4]*X_ptr[7:4]-2*X_ptr[7:4]*cnt_x[3:0]+cnt_x[3:0]*cnt_x[3:0])
                +(Y_ptr[7:4]*Y_ptr[7:4]+cnt_y[3:0]*cnt_y[3:0]-2*cnt_y[3:0]*Y_ptr[7:4]))) <= (r[9:5]*r[9:5]))
                 && ((((X_ptr[3:0]*X_ptr[3:0]-2*X_ptr[3:0]*cnt_x[3:0]+cnt_x[3:0]*cnt_x[3:0])+(Y_ptr[3:0]*Y_ptr[3:0]-2*Y_ptr[3:0]*cnt_y[3:0]+cnt_y[3:0]*cnt_y[3:0]))) <= (r[4:0]*r[4:0])))
                    candidate_tmp <= candidate_tmp+1;
            end

            2'b10:begin //set (A | B) - (A & B)
                if(
                    (((((X_ptr[7:4]*X_ptr[7:4]-2*X_ptr[7:4]*cnt_x[3:0]+cnt_x[3:0]*cnt_x[3:0])+(Y_ptr[7:4]*Y_ptr[7:4]+cnt_y[3:0]*cnt_y[3:0]-2*cnt_y[3:0]*Y_ptr[7:4]))) <= (r[9:5]*r[9:5]))
                || ((((X_ptr[3:0]*X_ptr[3:0]-2*X_ptr[3:0]*cnt_x[3:0]+cnt_x[3:0]*cnt_x[3:0])+(Y_ptr[3:0]*Y_ptr[3:0]-2*Y_ptr[3:0]*cnt_y[3:0]+cnt_y[3:0]*cnt_y[3:0]))) <= (r[4:0]*r[4:0])))
                &&
                !(((((X_ptr[7:4]*X_ptr[7:4]-2*X_ptr[7:4]*cnt_x[3:0]+cnt_x[3:0]*cnt_x[3:0])+(Y_ptr[7:4]*Y_ptr[7:4]+cnt_y[3:0]*cnt_y[3:0]-2*cnt_y[3:0]*Y_ptr[7:4]))) <= (r[9:5]*r[9:5]))
                && ((((X_ptr[3:0]*X_ptr[3:0]-2*X_ptr[3:0]*cnt_x[3:0]+cnt_x[3:0]*cnt_x[3:0])+(Y_ptr[3:0]*Y_ptr[3:0]-2*Y_ptr[3:0]*cnt_y[3:0]+cnt_y[3:0]*cnt_y[3:0]))) <= (r[4:0]*r[4:0])))
                    )
                    //candidate_tmp1 <= candidate_tmp1 +1;
                   //candidate_tmp2 <= candidate_tmp2+1;
                candidate_tmp <= candidate_tmp+1;
            end
        //default:mode <= 2'b00;
        endcase
    end
end

endmodule