The Akiko chip was only used in the CD32, and was primarily designed to perform chunky to planar conversion in hardware.  The Amigas graphics data is held in memory as planar data, which is fast and efficient to perform common 2 dimensional tasks with, such as scrolling a display in a game, but is slower for the sort of display that is used for creating the sort of display needed for games such as Doom II or Quake.  The intention was to make it easier to create these sorts of games for the CD32 by providing this hardware that could do this sort of conversion, but in practice, this didn’t turn out to be particularly useful.

Akiko is also responsible for interfacing with the double-speed CD-ROM drive in the CD32, and the keyboard/AUX serial port.