The Lava RSC is a family of very nice Famiclones that use ICs found in the original Famicom, complemented with an FPGA used to output an analog RGB picture.

From time to time, the people at Lava update the FPGA firmware to fix bugs and add new features. The high end model, the Lava RSC, includes an SD card slot connected to an MCU, and is capable of updating the FPGA autonomously, while the Lite version requires an FPGA programmer and not-so-easy to obtain Anlogic software to complete the update.

This board reproduces the upgrade circuitry found in a Lava RSC, but as an external module. This way it's sufficient to install headers on your Lite motherboard (there are well marked spots to solder one), if you want, bring out the signals via a flat cable, and connect this adapter when you want to perform the update. The rest works the same as the original Lava RSC (beside requiring a Lite-specific firmware, of course).