Psram

Doom on the ModRetro Chromatic with a VexRiscv in the GW5A-25 and 7.5 MB of PSRAM as main RAM: how the LiteX design made the port quick, and the measured ladder of gateware, compiler and renderer changes that took it from 6.4 to 31 fps.

How we moved the ModRetro Chromatic FPGA from a Gowin project with encrypted IP to an all-open LiteX design, one block at a time and never broken on hardware, and what it gave back to LiteX: a soft USB 2.0 PHY, an OPI PSRAM core and a new board target.