Patent ID: 7027064

Claim:
A method for write-back of modified graphics data, the method comprising: a) ordering a list of data blocks currently in a level one cache by a least recently used value determined for each data block; b) setting a pointer to point to a data block at the top of the list, wherein the data block at the top of the list has a largest least recently used value, and wherein a data block currently indicated by the pointer is a current data block; c) testing a dirty tag bit corresponding to the current data block, wherein the dirty tag bit indicates whether the data in the block is modified; d) setting the pointer to point to a next data block in the list, if the dirty tag bit indicates that the current data block is not modified, and returning to c); e) issuing a command to a memory request processor to write-back the current data block from the level one cache to a corresponding level two cache data block, if the dirty tag bit indicates that the current data block is modified; f) modifying the dirty tag bit corresponding to the current data block to indicate that the current data block is no longer modified and the memory locations are available for future allocation; and g) setting the pointer to point to a next data block in the list, and repeating steps c) through f) for each of the remaining data blocks in the list.