1 Introduction

It is imperative that information about status changes with the ethernet PHY be delivered to the MAC device in a timely and accurate manner. This becomes an important factor in systems designed for industrial applications that are time sensitive and require accuracy. For the purpose of this app note, the link drop status will be the focus. Regardless of cable length, the PHY must accurately and quickly indicate that a link has been dropped whenever there is a disturbance on the cable to prevent issues from propagating to the rest of the system.