I think this xLIBC function is what you're after: http://dcs.cemetech.net/index.php/DCSE:BasicLibs:DrawSprite#DrawSpriteTileBGA_.28TIOS_Values.29
This draws a small section of the tilemap as required (to restore a map after drawing a sprite).
This draws a small section of the tilemap as required (to restore a map after drawing a sprite).