Incremental updating of animated displays using copy-on-write semantics

Abstract

Tile buffers in a graphics processing system are managed using 'copy-on-write' semantics, in which tile data stored in a memory location is not transferred to another location until the tile data for one of the buffers is modified, thereby providing copy on flip behavior to support incremental updating of the data. Tile data for a new frame is written to one of the two memory spaces by reference to a first logical buffer that associates each tile with one of the memory spaces. Concurrently, tile data for a current frame is read from the two memory spaces by reference to a second logical buffer that also associates each tile with one of the memory spaces. In response to a frame flip signal, the tile associations of the second logical buffer are modified to match those of the first logical buffer. Subsequent tile data updates are written to the memory spaces by reference to the second logical buffer after modifying one of the first and second tile associations such that they no longer match.