d2

<?php
//Settlement
/**
 * @ORM\ManyToOne(targetEntity="Certificate\LocalizationBundle\Entity\Localization", inversedBy="settlement")
 */
private $localization;

//Localization
/**
 * @ORM\OneToMany(targetEntity="Certificate\LocalizationBundle\Entity\LocalizationSettlement", mappedBy="localization", cascade={"persist"})
 */
private $settlement;

//Controller
$localization = new Localization();

$localization->setCode(time());
$localization->setName('Name');
$localization->setStreet('street');
$localization->setZipCode(00-000);
$localization->setCity('WWA');

$settlement = new LocalizationSettlement();
$settlement->setPercent(75);
$localization->setSettlement($settlement);

$em = $this->get('doctrine.orm.entity_manager');
$em->persist($localization);

$em->flush();