VHDL implementation of MII transceiver. This is in the form of a Xilinx Vivado Project. The target for this project is the Lattice iCE5LP4K FPGA. I'm using Vivado for design and testing as I prefer it to the Lattice toolchain.
This is an implementation of a simple MII transceiver. Currently this only includes the transmitter and receiver. To use this, connect the data input and output to FIFOs. This is a work in progress and I'll probably add FIFO's later. For those unfamiliar with MII, there is a short tutorial on the Wiki.
The project is configured to take advantage of Vivado TCL scripting. Instead of committing the Vivido project, a TCL script is committed that sets up the Vivado project locally. All HDL source and testbench code goes in the /src directory. To get started do the following:
- start the Vivado IDE: ie.
./vivadoand enter the TCL console - run
source proj_tcl.tclfrom the TCL console
At this point a new directory called vhdl_mii will exist. This is where the Vivido project resides. Please do not commit any of the files from this directory.
I'm currently looking at MII to SPI conversion and decided to look into doing the conversion on an FPGA. There are not many commercially available ICs that do this. I started with this page and its accompanying examples.
The transceiver is simulated in /vhdl_mii.srcs/sim_1/imports/new/mii_testbench.vhd. The testbench simulates transmission and reception of an ethernet frame. Helpful resources for understanding the simulation are in /extras. The following are included:
- send_ethernet.py - Sends the packet used in the simulation over eth0. This is useful if you want to see the packet in real life. You'll need a Oscilloscope to see it.
- ethernet_crc.py - Generates the ethernet frame CRC for the packet in the simulation. Unless you view this packet on the MII interface using and Oscilloscope, you won't see this CRC.