`timescale 1ns / 1ps  // NW 31.10.10

module Divider(
  input clk, run,
  output stall,
  input [31:0] x, y,
  output [31:0] quot, rem);

reg [4:0] S;  // state
reg [31:0] r3, q2;
wire [31:0] r0, r1, r2, q0, q1, d;

assign stall = run & ~(S == 31);
assign r0 = (S == 0) ? 0 : r3;
assign d = r1 - y;
assign r1 = {r0[30:0], q0[31]};
assign r2 = d[31] ? r1 : d;
assign q0 = (S == 0) ? x : q2;
assign q1 = {q0[30:0], ~d[31]};
assign rem = r2;
assign quot = q1;

always @ (posedge(clk)) begin
  r3 <= r2; q2 <= q1;
  S <= run ? S+1 : 0;
end

endmodule