Patent ID: 8681159

Claim:
A method for switching from a first graphics processor to a second graphics processor to drive a display, comprising: for a first plurality of image frames, generating a signal source which drives the display using the first graphics processor, wherein the second graphics processor is in a non-active state for the first plurality of image frames; receiving a request to switch the signal source which drives the display from the first graphics processor to the second graphics processor; in response to the request, configuring the second graphics processor so that the second graphics processor is ready to drive the display, wherein configuring the second graphics processor comprises substantially synchronizing output display signals from the first graphics processor and output display signals from the second graphics processor using a phase locked loop, wherein substantially synchronizing the output display signals using a phase locked loop comprises: generating a reference frequency input using the phase locked loop; selecting the reference frequency input as an input for a timing generator corresponding to the second graphics processor; determining that the phase locked loop is phased-locked; in response to determining that the phase locked loop is phase-locked, switching the signal source which drives the display from the first graphics processor to the second graphics processor, thereby causing the second graphics processor to drive the display; and for a second plurality of image frames, generating a signal source which drives the display using the second graphics processor, wherein the first graphics processor is in a non-active state for the second plurality of image frames.