Disclosed is an edge management unit of accessing a memory including a first memory area and a second memory area. The edge management unit comprises an edge write controller writing bucket information corresponding to input edge data in the first memory area and the edge data at a location of the second memory area appointed by the bucket information; and an edge read controller responding to a scan line signal to read the bucket information from the first memory area and the edge data from a location of the second memory area appointed by the read bucket information.