Abstract: The system and method described provide for the detection and protection of memory accesses without the overhead typically incurred by memory management units. The processor includes a guarded memory unit, which monitors memory accesses to be performed by monitoring transmissions across the memory bus. The guarded memory unit includes a plurality of registers which identify memory addresses and modes which can cause a memory protection or detection violation to occur. If a memory protection violation occurs, a cancel signal is issued to cancel the memory operation prior to completion in order to protect the memory from unauthorized accesses. If a memory violation is detected, the memory operation is permitted to complete and a fault signal is issued to the processor to identify that a memory violation has been detected.

Abstract: The system and method described provide for the detection and protection of memory accesses without the overhead typically incurred by memory management units. The processor includes a guarded memory unit, which monitors memory accesses to be performed by monitoring transmissions across the memory bus. The guarded memory unit includes a plurality of registers which identify memory addresses and modes which can cause a memory protection or detection violation to occur. If a memory protection violation occurs, a cancel signal is issued to cancel the memory operation prior to completion in order to protect the memory from unauthorized accesses. If a memory violation is detected, the memory operation is permitted to complete and a fault signal is issued to the processor to identify that a memory violation has been detected.

Abstract: A microprocessor bus arbitration communications scheme for enhancing efficiency and performance of a multi-master bus system, typically within a computer system, including a central processing unit ("CPU") being a primary bus master, a bus arbiter and at least one alternative bus master coupled together by a bus. The CPU includes an internal memory element, a bus queue and bus control logic which collectively operate to generate a plurality of microprocessor bus arbitration signals to the bus arbiter. These microprocessor bus arbitration signals include a first bus arbitration signal indicating whether the CPU requires access to the bus and a second bus arbitration signal indicating that the CPU requires immediate access to the bus.