Despite a recent revision, IEEE 1588\u2122-2008 does not provide a complete implementation for PTP that accounts for variable delays introduced by network components. The disk drive includes a magnetic recording media, a pre-amplifier, an EAMR head, and at least one clock recovery circuit. With this, it becomes possible to effectively utilize the abnormality detection result. The pillar is ion implanted to form an ion-doped area in the pillar corner acting as a SD area.