Mike Field (hamster) of Hamsterworks has written a new tutorial on how to achieve a high-speed data transfer between two Papilio One 250k boards. The goal of the project was to achieve data transfer at 400 mbps, and Mike wound up exceeding the target by a pretty good margin.
From Mike’s project description,
The aim of this project is to get high speed data from one Spartan 3E FPGA to another over a single LVDS pair (and ground), and doing this without a common clock. Eventually I want to put fibre SFPs into the path allowing full electrical isolation, but getting the data between boards will only be covered here. My initial aim was to achieve 400Mb/s (line rate), quite an ambitious figure. Actual results are 512Mb/s (for 409.6 Mb/s once the 20% of coding overhead has been removed.
In the project notes, Mike describes the entirety of his efforts, from the hardware to how he reconciled the clocking and sampling, and of course the VHDL coding itself. Mike did a thorough job on the documentation for this, making it an easy project for anyone to replicate!
Please check out hamster’s project page for the full description and all the code used in it, and a big thanks to Mike for sharing with us! We would appreciate any input from our readers in the comments section!