A memory management unit that includes: (i) multiple data segment descriptors, each data segment descriptor associated with a data memory segment; (ii) multiple program segment descriptors, each program segment descriptor associated with a program memory segment; and (iii) a controller, adapted to replace the content of the multiple data segment descriptors and the multiple program segment descriptors in response to a task switch. A method for memory management, the method includes: (i) providing multiple data segment descriptors; each data segment descriptor associated with a data memory segment, and providing multiple program segment descriptors, each program segment descriptor associated with a program memory segment; (ii) receiving and storing a program task identifier and a data task identifier; (iii) receiving a data access request and determining how to handle the data access request in response to a content of the multiple data segment descriptors; and (iv) receiving a program access request and determining how to handle the program access request in response to a content of the multiple program segment descriptors.