A central processing unit and method for modifying its behavior and controlling access to a memory (120) having a plurality of memory locations for storing data values can include address range storage (170) for storing information identifying address ranges for a plurality of regions within the memory, and attribute storage (185) for storing, for each region, attributes where the attributes are linked to security, safety, or functionality during a program execution. The central processing unit further includes configuration logic (150) for configuring addresses and attribute of memory regions during the program execution and one or more execution logic units (150) associating attributes (and optionally metadata) to data processed by the central processing unit when data is accessed by the central processing unit and modifying instruction behaviors based on an instruction type and the attributes associated with the data being processed.