International Business Machines Corporation

Tracy James Bashore

Ahmed Gheith

Aditya Kumar

Ronald Lynn Rockhold

Andrew R Malota

Naresh Nayar

William Joseph Armstrong

Troy David Armstrong

Thomas A Liebsch

George F Eckman

A simulation technique that handles accesses to a frame of memory via a proxy object provides improved throughput in simulation environments. The proxy object, if present, processes the access at a head of a linked list of frames. If a check frame is not inserted in the list, the memory frame handles the request directly, but if a check frame is inserted, then the check operation is performed. The check frame can be a synchronization frame that blocks access to a memory frame while the check frame is present, or the check frame may be a breakpoint, watch or exception frame that calls a suitable handling routine. Additional check frames may be chained between the interface and the memory subsystem to handle synchronization, breakpoints, memory watches or other accesses to or information gathering associated with the memory frame.

Memory frame proxy architecture for synchronization and check handling in a simulator

Simulation method using memory frame proxy architecture for synchronization and check handling

A simulation technique that handles accesses to a frame of instruction memory by inserting a command object between a frame proxy and a memory frame provides improved throughput in simulation environments. The instruction frame, if present, processes the access to the frame. If an instruction frame is not present for the accessed frame, the memory frame handles the request directly. The instruction frame caches fetched and decoded instructions and may be inserted at the first access to a corresponding instruction memory frame. The instruction frame can track write accesses to instruction memory so that changes to the instruction memory can be reflected in the state of the instruction frame. Additional check frames may be chained between the interface and the memory frame to handle breakpoints, instruction memory watches or other access checks on the instruction memory frame.

Memory frame architecture for instruction fetches in simulation

A logical partition debugger allows debugging one logical partition in a computer system without requiring the shutdown of other logical partitions. The logical partition debugger is implemented in software in the partition manager. The logical partition debugger provides many common debug functions known in existing hardware and software debuggers, but does so in a manner that only the partition being debugged is affected.

Apparatus and method for debugging a logical partition

A method, apparatus, and computer program product are provided for processing an invalid address request in a computer system. A processor in the computer system receives an address requested from software and compares a real address requested with a real address range available. An invalid address request is a real address requested outside the real address range available. Responsive to identifying an invalid address, the processor issues an interrupt to supervising software. Then an address exception is posted to the user software, if appropriate.

Method and apparatus for processing an invalid address request

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Rochester, MN, United States of America

Tracy James Bashore