MDIO IP Core Solution


The MDIO core implements a Management Data Input/Output, or MDIO, interface master, also referred to as Station Management Entity (STA), that is capable of driving a 2-wire serial MDIO bus and managing MDIO interface slaves, also referred to as MDIO Manageable Devices (MMD). The MDIO core provides exclusive support for either Clause 22 of IEEE RFC802.3, the original Ethernet specification, or Clause 45 of IEEE 802.3ae specification.

A MDIO STA can be used to manage PHYs or physical layer devices in media access controllers (MACs) in Gigabit Ethernet equipment. The management of these PHYs is based on the access and modification of their various registers accomplished through the transaction of MDIO frames following either of the two protocols.


  • Implements a MDIO STA with support for either Clause 22, allowing access to up to 32 registers in 32 different devices, or Clause 45, allowing access to up to 65,536 registers in 32 different devices on 32 different ports. Clause 45 support is limited by the exclusion of read-increment-address MDIO accesses.
  • Programmable preamble prepending to the MDIO frame sent from the MDIO STA.
  • Programmable host clock division in the range of 2 to 510 for MDIO clock generation.