Abstract: A processor includes execution resources, data storage, and an instruction sequencing unit, coupled to the data storage and the execution resources, that supplies instructions within the data storage to the execution resources. The execution resources include a plurality of load-store units that each process only instructions that access data having associated addresses within a respective one of a plurality of subsets of an address space. The load-store units can have diverse hardware such that a maximum number of instructions that can be concurrently executed is different for different load-store units or such that some of the load-store units are restricted to executing certain classes of instructions.

Abstract: A method of extending a cache of a processing unit in a multi-processor computer system, by expanding the prior-art MESI cache-coherency protocol to include an additional cache-entry state corresponding to a most recently accessed state. A value is loaded from system memory into one or more caches of adjacent processing units, and when a requesting processing unit issues an inquiry onto the system bus to read the value, the value is sourced from the cache of the adjacent processing unit containing a copy of the value that was most recently accessed. Each cache has at least one cache line with a block for storing the value, and an indication is provided that a cache line having a block which contains an instruction or data is in a “recently read” state. Each cache entry has three bits to indicate the current state of the cache entry (one of five possible states).

Abstract: A processor having a hashed and partitioned storage subsystem includes at least one execution unit, an instruction sequencing unit coupled to the execution unit, and a cache subsystem including a plurality of caches that store data utilized by the execution unit. Each cache among the plurality of caches stores only data having associated addresses within a respective one of a plurality of subsets of an address space. In one preferred embodiment, the execution units of the processor include a number of load-store units (LSUs) that each process only instructions that access data having associated addresses within a respective one of the plurality of address subsets. The processor may further be incorporated within a data processing system having a number of interconnects and a number of sets of system memory hardware that each have affinity to a respective one of the plurality of address subsets.

Abstract: A data processing system includes an interconnect, a plurality of nodes coupled to the interconnect that each include at least one agent, response logic within each node, and a queue. In response to snooping a transaction on the interconnect, each agent outputs a snoop response. In addition, the queue, which has an associated agent, allocates an entry to service the transaction. The response logic within each node accumulates a partial combined response of its node and any preceding node until a complete combined response for all of the plurality of nodes is obtained. However, prior to the associated agent receiving the complete combined response, the queue speculatively deallocates the entry if the partial combined response indicates that an agent other than the associated agent will service the transaction.

Abstract: A multiprocessor system bus protocol system and method for processing and handling a processor request within a multiprocessor system having a number of bus accessible memory devices that are snooping on. at least one bus line. Snoop response groups which are groups of different types of snoop responses from the bus accessible memory devices are provided. Different transfer types are provided within each of the snoop response groups. A bus master device that provides a bus master signal is designated. The bus master device receives the processor request. One of the snoop response groups and one of the transfer types are appropriately designated based on the processor request. The bus master signal is formulated from a snoop response group, a transfer type, a valid request signal, and a cache line address. The bus master signal is sent to all of the bus accessible memory devices on the cache bus line and to a combined response logic system.

Abstract: A method and system for scarfing data during a data access transaction within a hierarchical data storage system. A data access request is delivered from a source device to a plurality of data storage devices. The access request includes a target address and a source path tag, wherein the source path tag includes a device identification tag that uniquely identifies a data storage device within a given level of the system traversed by the access request. A device identification tag that uniquely identifies the third party transactor within a given memory level is appended to the source path tag such that the third party transactor can scarf returning data without reserving a scarf queue entry.

Abstract: A method and system for processing a split data access transaction within a hierarchical data storage system. In accordance with the method of the present invention, a data access request is delivered from a source device onto an address bus that is shared by a plurality of data storage devices within the hierarchical data storage system, wherein the data access request includes a target address and a source path tag. The source path tag includes at least one device identification tag that uniquely identifies at least one data storage device within each level of the hierarchical data storage system traversed by the data access request. In response to a data access request hit at a given data storage device, a data access response is delivered onto a data bus, wherein the data access response includes the source path tag and the target address.

Abstract: A method and system for managing a data access transaction within a hierarchical data storage system. In accordance with the method of the present invention, a data access request is delivered from a source device to multiple data storage devices within the hierarchical data storage system. The data access request includes a source path tag and a target address. At least one device identification tag is added to the source path tag, wherein the at least one device identification tag uniquely identifies a data storage device within each level of the hierarchical data storage system traversed by the data access request such that the data access transaction can be processed in accordance with source path information that is incrementally encoded within the data access request as the data access request traverses the hierarchical data storage system.

Abstract: A Fully Interconnected System Architecture (FISA) for an improved data processing system. The data processing system topology has a processor chip and external components to the processor chip, such as memory and input/output (I/O) and other processor chips. The processor chip is interconnected to the external components via a point-to-point bus topology controlled by an intra-chip integrated, distributed switch (IDS) controller. The IDS controller provides the chip with the functionality to provide a single bus to each external component and provides an overall total bandwidth greater than traditional topologies while reducing latencies between the processor and the external components. The design of the processor chip with the intra-chip IDS controller provides a pseudo “distributed switch” which may separately access distributed external components, such as memory and I/Os, etc.

Abstract: In response to a need to initiate a global operation, a bus master within a multiprocessor system issues a combined token and operation request on a bus coupled to the bus master. The combined token and operation request solicits a token required to complete the global operation and identifies the global operation to be processed with the token, if granted. Upon receiving a combined response acknowledging both the token and operation portions of the combined request, the bus master treats the global operation as complete. If a combined response acknowledging the token portion of the combined request but retrying the operation portion (i.e., at least one snooper is busy processing a previous global operation), the bus master issues an operation request (only) for the operation portion of the combined request.

Abstract: An apparatus for transmitting packets within a symmetric multiprocessor system is disclosed. The symmetric multiprocessor system includes multiple processing nodes, with multiple agents at each node, connected to each other via an interconnect. A request transaction is initiated by a master agent in a master node to all receiving nodes. A write counter number is generated for associating with the request transaction. The master agent then waits for a combined response from the receiving nodes. After the receipt of the combined response, a data packet is sent from the master agent to an intended one of the receiving nodes according to the combined response. After the data packet has been sent, the master agent in the master node is ready to send another request transaction along with a new write counter number, without the necessity of waiting for an acknowledgement from the receiving node.

Abstract: A computer system of a number of processing nodes operate either in a loop configuration or off of a common bus with high speed, high performance wide bandwidth characteristics. The processing nodes in the system are also interconnected by a separate narrow bandwidth, low frequency recovery bus. When problems arise with node operations on the high speed bus, operations are transferred to the low frequency recovery bus and continue there at a slower rate for recovery operations. The recovery technique may be used to increase system speed and performance on a dynamic basis.

Abstract: A data processing system includes at least first and second nodes and a segmented interconnect having coupled first and second segments. The first node includes the first segment and first and second agents coupled to the first segment, and the second node includes the second segment and a third agent coupled to the second segment. The first node further includes cancellation logic that, in response to the first agent issuing a request on the segmented interconnect that propagates from the first segment to the second segment and the second agent indicating ability to service the request, sends a cancellation message to the third agent instructing the third agent to ignore the request.

Abstract: A data processing system includes an interconnect and first and second nodes, coupled to the interconnect, that each include at least one agent. Each agent within the first and second nodes outputs a snoop response in response to snooping a transaction on the interconnect. Utilizing the snoop response of each agent within the first node, first response logic within the first node produces a first cumulative combined response. This first cumulative combined response is then combined by second response logic in the second node with the snoop response of each agent in the second node to produce a second cumulative combined response. After a complete combined response is obtained in this manner, the complete combined response is distributed to all nodes so that each agent can determine its response, if any, to the transaction.

Abstract: A processor having a hashed and partitioned register file includes at least one execution unit, an instruction sequencing unit coupled to the execution unit, and a plurality of registers coupled to the execution unit. The plurality of registers are partitioned into a plurality of groups, such that registers within each group can store only data having associated addresses within a respective one of a plurality of subsets of an address space.

Abstract: In response to a need to initiate one or more global operations, a bus master within a multiprocessor system issues a combined token and operation request in a single bus transaction on a bus coupled to the bus master. The combined token and operation request solicits a single existing token required to complete the global operations within the multiprocessor system and identifies the first of the global operations to be processed with the token, if granted. Once a bus master is granted the token, no other bus master will be granted the token until the current token owner explicitly requests release. The current token owner repeats the combined token and operation request for each global operation which needs to be initiated and, on the last global operation, issues a combined request with an explicit release. Acknowledgement of the combined request with release implies release of the token for use by other bus masters.

Abstract: A method and system for processing a split data access transaction within a hierarchical data storage system. In accordance with the method of the present invention, a data access request is delivered from a source device onto an address bus that is shared by a plurality of data storage devices within the hierarchical data storage system, wherein the data access request includes a target address and a source path tag. The source path tag includes at least one device identification tag that uniquely identifies at least one data storage device within each level of the hierarchical data storage system traversed by the data access request. In response to a data access request hit at a given data storage device, a data access response is delivered onto a data bus, wherein the data access response includes the source path tag and the target address.

Abstract: A method and system for managing a data access transaction within a hierarchical data storage system. In accordance with the method of the present invention, a data access request is delivered from a source device to multiple data storage devices within the hierarchical data storage system. The data access request includes a source path tag and a target address. At least one device identification tag is added to the source path tag, wherein the at least one device identification tag uniquely identifies a data storage device within each level of the hierarchical data storage system traversed by the data access request such that the data access transaction can be processed in accordance with source path information that is incrementally encoded within the data access request as the data access request traverses the hierarchical data storage system.

Abstract: A method and system for scarfing data during a data access transaction within a hierarchical data storage system. A data access request is delivered from a source device to a plurality of data storage devices. The access request includes a target address and a source path tag, wherein the source path tag includes a device identification tag that uniquely identifies a data storage device within a given level of the system traversed by the access request. A device identification tag that uniquely identifies the third party transactor within a given memory level is appended to the source path tag such that the third party transactor can scarf returning data without reserving a scarf queue entry.

Abstract: In response to a need to initiate a global operation, a bus master within a multiprocessor system issues a combined token and operation request on a bus coupled to the bus master. The combined token and operation request solicits one of a plurality of tokens required to complete the global operation and identifies the global operation to be processed with the token, if granted. Bus snoopers contain a number of snooper queues for global operations equal to the number of global operation tokens employed within the multiprocessor system. A bus snooper, upon detecting a combined token and operation request, begins speculatively processing the operation if the snooper is not already busy. Before completing the operation, the snooper watches for a combined response with a token number acknowledging either the combined request or a subsequent token request from the same processor, which indicates that the originating bus master has been granted a token for completing a global operation.