Example servo control module in Verilog. Sweeps 4 servo motors back and forth at different speeds.

mojo_top_servo_demo.v

/*
  Servo motor control demo module
  Four servos swing back and forth with different speeds.
*/
module mojo_top(
  input clk, // 50MHz clock input
  //remaining default inputs/outputs omitted
  output [3:0] servo_out //PWM output lines for each servo
  );
  //Usual setup code omitted (setting SPI lines, reset, etc.
  localparam NUM_SERVOS = 4;

  //pos is a 32 bit array (8 bits per servo)
  wire [(NUM_SERVOS*8)-1:0] pos;
  genvar i;
  //Generate a serparate up/down counter for each servo
  //Each one moves at a different speed (different CTR_LEN)
  generate
    for (i = 0; i < NUM_SERVOS; i=i+1) begin: counter_gen_loop
      counter #(.CTR_LEN(26+i)) pos_counter (
        .clk(clk),
        .rst(rst),
        .value(pos[(i+1)*8-1:i*8])
      );
    end
  endgenerate

  //loop to generate the servo controllers, 1 per servo.
  //each has its position wired to the corresponding up/down counter above.
  generate
    for (i = 0; i < NUM_SERVOS; i=i+1) begin: servo_gen_loop
      servo_controller servo_sweep (
        .clk(clk),
        .rst(rst),
        .position(pos[(i+1)*8-1:i*8]),
        .servo(servo_out[i])
      );
    end
  endgenerate
endmodule