International Business Machines Corporation

Zhongru Julia Lin

Nadeem Malik

Avijit Saha

Chandrasekhar Narayanaswami

Brett Adam St Onge

Mehrdad Soheili-Arasi

A method and apparatus for verifying memory coherency of a simulated computer system. A verification logic unit is used for detecting the issuance of load and store instructions from the simulated system. Targets (registers or memory locations) representing the detected instructions are then stored in queues, and marked (colored) as not having been executed. After a detected instruction has been executed and completed, the corresponding target in the queue is marked as being completed. During every clock cycle of the apparatus, the verification logic unit monitors the queues for entries (Targets) marked as completed, which are then discarded.

Method and system for detecting the issuance and completion of processor

An improved method and system for creating state machines in microcode. State machines are typically defined by a plurality having at least a combinations of current state, next state. Each one of the current states and next states are typically assigned unique values to distinguish them from other current states and next states, respectively. Upon an examination of the binary bit representations for the combinations, certain repetitive patterns become apparent between certain sections of the combinations. These recognized repetitive bit patterns are grouped and represented by linked lists and associated with one another to form the necessary relationship to define the represented combinations. Thus, saving memory and/or storage resources.

Method for implementing state machine using link lists by dividing each

An efficient method and system within a data processing system for storing address tags are disclosed, which include a tag directory having a plurality of congruence classes, wherein each congruence class is arranged as a tree-like data structure. A portion of an address tag common to a plurality of address tags is stored in an entry within a node at a first level of a tree-like data structure corresponding to a congruence class of the directory. Portions of the plurality of address tags are stored in a node at a subsequent level of the tree-like data structure, such that all of the plurality of address tags share in common the portion stored in the entry within the node at the first level. Since a portion common to a plurality of address tags is stored only once, the memory space required to store the plurality of address tags is reduced.

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Austin, TX, United States of America

Zhongru Julia Lin