Computer graphics processing and selective visual display system – Display peripheral interface input device – Light pen for fluid matrix display panel
Patent
1996-01-16
1998-05-19
Wu, Xiao
Computer graphics processing and selective visual display system
Display peripheral interface input device
Light pen for fluid matrix display panel
345112, 395507, G09G 500
Patent
active
057541701
ABSTRACT:
A graphics controller overlays a movie window over the graphics pixel data. Movie pixels are from a movie source and are muxed into the pixel path by a pixel mux near the end of the graphics pipeline. A comparison of the current pixel count to the pixel address of the start and ending boundaries of the movie window controls the pixel mux, which selects either graphics pixels or movie pixels for display to a screen. Since the graphics controller is pipelined, the pixel compare near the end of the pipeline does not restart the graphics pipeline early enough for it to pre-process the graphics pixels. The graphics pipeline does not stop during the movie window but instead performs dummy fetches from the graphics memory to a CRT FIFO in the graphics pipeline. Dummy fetches are fetches of graphics pixels that are not displayed. Since these fetches contain non-displayed pixels, they are not needed except to keep the fetch count counting even during the movie window. Other requests are given priority during dummy fetches. Thus fetches to fill the CRT FIFO with pixels underneath the movie overlay which are not displayed are transparently blocked by activating dummy fetches, allowing other requestors to have full access to the graphics memory. Dummy fetches are activated by a compare of the fetch counts to the width of the graphics and movie portions of the screen, expressed in memory fetches rather than in pixels. A comparison of the total fetches in a horizontal line to the current fetch count prevents fetching un-displayed pixels past the end of the line.
REFERENCES:
patent: 4710761 (1987-12-01), Kapur
patent: 5146211 (1992-09-01), Adams et al.
patent: 5146592 (1992-09-01), Pfeiffer et al.
patent: 5179639 (1993-01-01), Taaffe
patent: 5208583 (1993-05-01), Cusick et al.
patent: 5208745 (1993-05-01), Quentin et al.
patent: 5216413 (1993-06-01), Seiler et al.
patent: 5233686 (1993-08-01), Rickenbach et al.
patent: 5264837 (1993-11-01), Buehler
patent: 5276437 (1994-01-01), Horvath et al.
patent: 5293540 (1994-03-01), Trani et al.
patent: 5319382 (1994-06-01), Fitzpatrick et al.
patent: 5345554 (1994-09-01), Lippincott et al.
patent: 5375203 (1994-12-01), Lambidakis
patent: 5398075 (1995-03-01), Ferytag et al.
patent: 5404437 (1995-04-01), Nguyen
patent: 5432905 (1995-07-01), Hsieh et al.
patent: 5608864 (1997-03-01), Bindlish et al.
Auvinen Stuart T.
NeoMagic Corp.
Wu Xiao
Wu Xu-Ming
LandOfFree
Transparent blocking of CRT refresh fetches during video overlay does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Transparent blocking of CRT refresh fetches during video overlay, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transparent blocking of CRT refresh fetches during video overlay will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1856990