I forgot what the dma mode is...but the cheat options is like an action replay/game shark. It adds "cheats" not normally found in a game, like say infinute objections in pheonix wright, or one hit deaths in ultimate mortal kombat, provided the code to let the codes work has been pre-entered/the cheat database has it included.
Oh so people just send in cheats to the ttds site and if you update the firmware regularly, you'll automatically have the cheat codes? crazy.