A data processing system has a microprocessor that is operable in real and protected address generation modes. Transition from the real mode to the protected mode is done by initializing system tables and pointer registers, switching from the real mode to the protected mode, and flushing a prefetch queue...http://www.google.com.au/patents/US5404471?utm_source=gb-gplus-sharePatent US5404471 - Method and apparatus for switching address generation modes in CPU having plural address generation modes
