The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 21, 2003
Filed:
Nov. 25, 2002
Steven L. Morein, Cambridge, MA (US);
Michael T. Wright, Marlborough, MA (US);
Kin M. Yee, Quincy, MA (US);
ATI International Srl, , BB;
Abstract
A method and apparatus for managing compressed Z information in a video graphics system is described. Pixels in a display frame are grouped into a plurality of pixel blocks, where each pixel block includes a plurality of pixels. When possible, the Z information corresponding to the plurality of pixels in a pixel block is compressed and stored in a Z buffer in a compressed format. A Z mask value for each pixel block in the frame is stored in a Z mask memory, where the Z mask for each pixel block indicates a level of compression of the Z information for each of the pixel blocks. When Z information for a pixel block is required for processing operations, a cache is first examined to determine if the Z information for the pixel block is included in the cache. If the Z information is not included in the cache, the Z mask memory is consulted to determine the level of compression of the Z information for the particular pixel block. Based on the indication provided by the Z mask memory as to the level of compression, a predetermined amount of data is retrieved from the Z buffer, and when the Z information is in compressed format, it is decompressed. The fetched Z information is then stored in the cache for use in video graphics processing.