The Libre-SOC project has been prototyped using an Lattice ECP5 FPGA before its first tapeout. Since then many things have changed. One big change is the use of a different controller for DDR3 called gram. To get DDR3 working on the OrangeCrab many changes are needed.

This talk will provide an overview on my work on Libre-SOC in the past two years, an overview of DDR SDRAM interfaces and the PHYs commonly found on FPGAs and some ways to debug the OrangeCrab using a BeagleWire.