US 7,576,771 B1
Method and apparatus of providing video synchronization
Kenneth J. Kotlowski, Berthoud, Colo. (US); and Daniel Daugherty, Loveland, Colo. (US)
Assigned to Advanced Micro Devices, Inc., Sunnyvale, Calif. (US)
Filed on Mar. 08, 2005, as Appl. No. 11/75,303.
Int. Cl. H04N 17/02 (2006.01); H04N 5/21 (2006.01); H04N 5/08 (2006.01)
U.S. Cl. 348—194  [348/616; 348/533; 348/525] 18 Claims
OG exemplary drawing
 
1. A method comprising the steps of:
determining a video control signal received at a video subsystem of an integrated circuit is a valid video control signal in response to a transition of the video control signal from a first logic state to a second logic state occurring at a predetermined time range;
determining the video control signal is an invalid video control signal in response to a transition of the video control signal from the first logic state to the second logic state not occurring at the predetermined time range;
in response to determining a valid video control signal is received, providing a delayed representation of the video control signal to an input of a display engine, wherein the delayed representation represents the video control signal delayed by a first predetermined amount and comprises a first pulse edge provided to the display engine at a first time; and
in response to determining an invalid video control signal is received, providing an alternate video control signal to the input of the display engine, the alternate video signal comprising a second pulse edge provided at approximately the first time.