Patent ID: 8561169

Claim:
A data processing apparatus, comprising: a display buffer for storing an array of display elements for subsequent output to a display controller, the display elements within the array comprising both secure display elements and non-secure display elements, and each display element having a security permission indication associated therewith identifying whether that display element is one of said secure display elements or one of said non-secure display elements; at least one processing unit for executing a non-secure process and a secure process, each process issuing access requests when seeking to access display elements in the display buffer, each access request specifying a location in said display buffer; and interface logic associated with the display buffer for receiving each access request, and configured for at least each access request issued by the non-secure process to determine the security permission indication associated with the display element currently stored at the location specified by that access request, and to determine how that access request should be processed dependent on the determined security permission indication.