Patent ID: 8823722

Claim:
A single integrated circuit, comprising: a first display controller configured to control a non-bistable display screen, wherein images disappear from the non-bistable display screen when power to the non-bistable display screen is turned off; a second display controller configured to control a bistable display screen, wherein images do not disappear from the bistable display screen when power to the bistable display screen is turned off; a memory controller configured to control a memory; a processor configured to write first display data to a first frame buffer in the memory, and to write second display data to a second frame buffer in the memory, wherein the first display controller is further configured to update the non-bistable display screen according to contents of the first frame buffer, and wherein the second display controller is further configured to update the bistable display screen according to contents of the second frame buffer; and a snooping circuit configured to (i) determine when the second display data is written to the second frame buffer, and (ii) provide a snooping signal in response to the second display data being written to the second frame buffer, wherein the second display controller is further configured to update the bistable display screen in response to the snooping signal indicating that the second display data was written to the second frame buffer.