International Business Machines Corporation

Stacey G Lloyd

Thomas Benjamin Berg

Bruce Michael Gilbert

Redefined hardware structured transactions and the associated responses in a data processing device are made user programmable. Three registers, a identifier register, a mask register and a response register, are used to redirect transactions or other operations within an application specific integrated circuit after post-silicon testing has been completed and there is no opportunity to redirect the hardware logic contained therein. When enabled, the registers allow for the insertion of blank table entries that can be programmed at a later time to handle unexpected output responses which occur due to unforeseen problems in the preprogrammed operation of the device. Transaction redirection can be accomplished on selected fields of identified transactions. The method is applicable to any hardware device in which it is desired to redirect actions originally defined in look-up tables when such tables are not capable of adjustment or alteration without redesign or re-manufacture.

Transaction redirection mechanism for handling late specification changes and design errors

A method is provided for allocating system resources across multiple nodes of a system communicating through a hardware device. The method provides for allocation of transaction units or identifiers in an allocating component for use in a multiple target component which may be in a distinct target node within the multiple node system. Based on the operations or requests that a target node receives from multiple external request source nodes, each requiring the use of target transaction unit objects such as transaction identification bits, the method provides inclusion of such information in the initial request to a target node which allows any data transmission between the source node and the target node, or the target node and the source node to be accomplished without any further intervention by the allocating component. Such component may be a local memory control agent or device.

Distributed allocation of system hardware resources for multiprocessor systems

Allocating potentially needed resources for a transaction before having completely received the transaction is disclosed. An initial part of a transaction is received in first clock cycle. The resources potentially needed by the transaction are determined based on the initial part thereof that has been received, and allocated. The transaction then proceeds. The final part of the transaction is received in a final clock cycle. The resources actually needed by the transaction from the resources previously allocated are determined based on the remaining part thereof that has been received. Any unneeded remaining resources are then deallocated.

Allocation of potentially needed resources prior to complete transaction receipt

A method of classification of transaction address conflicts in a computer system for ensuring efficient ordering in a two-level snoopy cache architecture. The disclosure provides a method of classification and handling of address conflicts within a system to minimize the impact that address ordering places in a multiprocessor system with multiple memory control agents generating potentially conflicting addresses. A set of classification for each potential transaction conflict is provided against which decisions are provided which identifies the earliest point at which a subsequent transaction within the system may proceed to the same address identified by a previous transaction in the system. Classification of transactions are provided in several high level classes which define how such transactions within the system are handled based on the method disclosed.

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Manassas, VA, United States of America

Stacey G Lloyd