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MAC

MAC

This project was aimed at investigating the data transfer on Ethernet media. It consisted of three parts:

  • data transfer on copper media with a real-time protocol (RT-Mac)
  • transfer of I/O data on copper media with a simple protocol, no microprocessor (IO-Mac)
  • fibre optic data transfer (FO-Mac).
     

An interface block buffer was developed to receive and send Ethernet frames through the standard MII interface. It synchronises the signals from the physical interface to the processing system through dual-port memories. This interface block buffer was used in every step of the project.

Data transfer with a real-time protocol is based on specifications similar to the Powerlink standard. A master emits beacon signals and queries the various participants that announce themselves through an announcement protocol. In order not to disturb the system, it is separated from the rest of the network through a bridge that transmits the sampled signal to the exterior world.

The transfer of I/O data is based on specifications similar to the EIB standard with features comparable to the features of home automation: A node can send and receive several values, several nodes can control a participant, several participants can be steered by the same control, etc.

Fibre optic data transfer is asymmetrical: It includes an interface node (OLT) that communicates with several target nodes (ONU). This project allows the traffic from a 10/100Base-T Ethernet network to be transformed into a 1000Base-T connection with FPGA, and also to transform electrical signals into optical signals and vice versa. The optical transmission is based on the EPON standard (Ethernet Passive Optical Network).