Waits until next fixed frame rate update function. See Also: FixedUpdate.

yield new WaitForFixedUpdate ();

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    IEnumerator Example() {
        yield return new WaitForFixedUpdate();
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Example() as IEnumerator:
		yield WaitForFixedUpdate()