Small Things Retro

In the recently released SNESTang 0.3, a softcore-based I/O system is added to enhance the menu system and file system support. Let us explore how this works. Part one of the article discusses why the soft core is necessary, choice of CPU to use and how it works with the SDRAM.

This documents the design of SNESTang 0.3 for my own reference and others who want to read the code. It also aims to be helpful to people porting other cores to Tang FPGAs.