Abstract: A system comprises a first processing block configured to receive, from a first local resource, a formatted transaction in a format that is not recognizable by a remote endpoint; determine a first transaction category, from among a plurality of transaction categories, of the formatted transaction based on content of the formatted transaction; perform one or operations on the formatted transaction based on the first transaction category to form a reformatted transaction in a format that is recognizable by the remote endpoint; and place the reformatted transaction in a queue for transmission to the remote endpoint.

Abstract: A system and method of recovering from errors in a data processing system. The data processing system includes one or more processor cores coupled to one or more memory controllers. The one or more memory controllers include at least a first memory interface coupled to a first memory and at least a second memory interface coupled to a second memory. In response to determining an error has been detected in the first memory, access to the first memory via the first memory interface is inhibited. Also, the first memory interface is locally restarted without restarting the second memory interface.

Abstract: A method and apparatus are provided for a support interface for memory-mapped resources. A support processor sends a sequence of commands over and FSI interface to a memory-mapped support interface on a processor chip. The memory-mapped support interface updates memory, memory-mapped registers or memory-mapped resources. The interface uses fabric packet generation logic to generate a single command packet in a protocol for the coherency fabric which consists of an address, command and/or data. Fabric commands are converted to FSI protocol and forwarded to attached support chips to access the memory-mapped resource, and responses from the support chips are converted back to fabric response packets. Fabric snoop logic monitors the coherency fabric and decodes responses for packets previously sent by fabric packet generation logic. The fabric snoop logic updates status register and/or writes response data to a read data register. The system also reports any errors that are encountered.

Abstract: In a multiprocessor environment, by executing cache-inhibited reads or writes to registers, a scan communication is used to rapidly access registers inside and outside a chip originating the command. Cumbersome locking of the memory location may be thus avoided. Setting of busy latches at the outset virtually eliminates the chance of collisions, and status bits are set to inform the requesting core processor that a command is done and free of error, if that is the case.

Abstract: A method and system for speculatively pre-fetching data from a memory. A memory controller on a data bus “snoops” data requests put on the data bus by a bus control logic. Based on information in the header of the data request, such as transaction type, tag, transaction size, etc., a speculative pre-fetch is made to read data from the memory associated with the memory controller. If the speculative fetch turns out to be correct, then the memory controller makes an assumption that the pre-fetch was too conservative (non-speculative), and a pre-fetch for a next data request is performed at an earlier more speculative time. If the speculative fetch turns out to be incorrect, then the memory controller makes an assumption that the pre-fetch was too speculative (made early), and a pre-fetch for a next data request is performed at a later less speculative time.

Abstract: The present invention provides an improved method, an system, and a set of computer implemented instructions for handling a cache containing multiple single-bit hard errors on multiple addresses within a data processing system. Such handles will prevent any down time by logging in the parts to be replaced by an operator when certain level of bit errors is reached. When a hard error exists on a cache address for the first time, serviceable first hard error, that cache line is deleted. Thus the damaged memory device is no longer used by the system. As a result, the system is running with “N−x” lines wherein “N” constitutes the total number of existing lines and “x” is less than “N”. An alternative method is to exchange the damaged memory device to a spare memory device. In order to provide such services, the system must first differentiate whether an error is a soft or hard error.

Abstract: An apparatus for providing concurrent communications between multiple memory devices and a processor is disclosed. Each of the memory device includes a driver, a phase/cycle adjust sensing circuit, and a bus alignment communication logic. Each phase/cycle adjust sensing circuit detects an occurrence of a cycle adjustment from a corresponding driver within a memory device. If an occurrence of a cycle adjustment has been detected, the bus alignment communication logic communicates the occurrence of a cycle adjustment to the processor. The bus alignment communication logic also communicates the occurrence of a cycle adjustment to the bus alignment communication logic in the other memory devices. There are multiple receivers within the processor, and each of the receivers is designed to receive data from a respective driver in a memory device. Each of the receivers includes a cycle delay block.

Abstract: A non-uniform memory access (NUMA) computer system includes a remote node coupled by a node interconnect to a home node having a home system memory. The remote node includes a local interconnect, a processing unit and at least one cache coupled to the local interconnect, and a node controller coupled between the local interconnect and the node interconnect. The processing unit first issues, on the local interconnect, a read-type request targeting data resident in the home system memory with a flag in the read-type request set to a first state to indicate only local servicing of the read-type request. In response to inability to service the read-type request locally in the remote node, the processing unit reissues the read-type request with the flag set to a second state to instruct the node controller to transmit the read-type request to the home node.

Abstract: A non-uniform memory access (NUMA) computer system includes a remote node coupled by a node interconnect to a home node including a home system memory. The remote node includes a plurality of snoopers coupled to a local interconnect. The plurality of snoopers includes a cache that caches a cache line corresponding to but modified with respect to data resident in the home system memory. The cache has a cache controller that issues a deallocate operation on the local interconnect in response to deallocating the modified cache line. The remote node further includes a node controller, coupled between the local interconnect and the node interconnect, that transmits the deallocate operation to the home node with an indication of whether or not a copy of the cache line remains in the remote node following the deallocation. In this manner, the local memory directory associated with the home system memory can be updated to precisely reflect which nodes hold a copy of the cache line.

Abstract: A non-uniform memory access (NUMA) data processing system includes a plurality of nodes coupled to a node interconnect. The plurality of nodes contain a plurality of processing units and at least one system memory having a table (e.g., a page table) resident therein. The table includes at least one entry for translating a group of non-physical addresses to physical addresses that individually specifies control information pertaining to the group of non-physical addresses for each of the plurality of nodes. The control information may include one or more data storage control fields, which may include a plurality of write through indicators that are each associated with a respective one of the plurality of nodes. When a write through indicator is set, processing units in the associated node write modified data back to system memory in a home node rather than caching the data.

Abstract: A non-uniform memory access (NUMA) computer system and associated method of operation are disclosed. The NUMA computer system includes at least a remote node and a home node coupled to an interconnect. The remote node contains at least one processing unit coupled to a remote system memory, and the home node contains at least a home system memory. To reduce access latency for data from other nodes, a portion of the remote system memory is allocated as a remote memory cache containing data corresponding to data resident in the home system memory. In one embodiment, access bandwidth to the remote memory cache is increased by distributing the remote memory cache across multiple system memories in the remote node.

Abstract: A computer system includes a processing unit, a system memory, and a memory controller coupled to the processing unit and the system memory. According to the present invention, the memory controller accesses the system memory to obtain prefetch data and transmits the prefetch data to the processing unit in a prefetch write operation specifying the processing unit in a destination field. In one embodiment, the memory controller transmits the prefetch write operation in response to receipt of a prefetch hint from the processing unit, which may accompany a read-type request by the processing unit. This prefetch methodology may advantageously be implemented imprecisely, with the memory controller responding to the prefetch hint only if a prefetch queue is available and ignoring the prefetch hint otherwise. The processing unit may similarly ignore the prefetch write operation if no snoop queue is available.

Abstract: A computer system includes a home node and one or more remote nodes coupled by a node interconnect. The home node includes a local interconnect, a node controller coupled between the local interconnect and the node interconnect, a home system memory, and a memory controller coupled to the local interconnect and the home system memory. In response to receipt of a data request from the remote node, the memory controller transmits requested data from the home system memory to the remote node and, in a separate transfer, conveys responsibility for global coherency management for the requested data from the home node to the remote node. By decoupling responsibility for global coherency management from delivery of the requested data in this manner, the memory controller queue allocated to the data request can be deallocated earlier, thus improving performance.

Abstract: A non-uniform memory access (NUMA) computer system includes at least one remote node and a home node coupled by a node interconnect. The home node contains a home system memory and a memory controller. In response to receipt of a data request from a remote node, the memory controller determines whether to grant exclusive or non-exclusive ownership of requested data specified in the data request by reference to history information indicative of prior data accesses originating in the remote node. The memory controller then transmits the requested data and an indication of exclusive or non-exclusive ownership to the remote node.

Abstract: A non-uniform memory access (NUMA) computer system includes a node interconnect to which a remote node and a home node are coupled. The home node contains a home system memory, and the remote node includes at least one processing unit and a cache. In response to the cache deallocating an unmodified cache line that corresponds to data resident in the home system memory, a cache controller of the cache issues a deallocate operation on a local interconnect of the remote node. In one embodiment, the deallocate operation is further transmitted to the home node via the node interconnect only in response to an indication, such as a combined response, that no other cache in the remote node caches the cache line. In response to receipt of the deallocate operation, a memory controller in the home node updates a local memory directory associated with the home system memory to indicate that the remote node does not hold a copy of the cache line.

Abstract: A non-uniform memory access (NUMA) computer system includes a first node and a second node coupled by a node interconnect. The second node includes a local interconnect, a node controller coupled between the local interconnect and the node interconnect, and a controller coupled to the local interconnect. In response to snooping an operation from the first node issued on the local interconnect by the node controller, the controller signals acceptance of responsibility for coherency management activities related to the operation in the second node, performs coherency management activities in the second node required by the operation, and thereafter provides notification of performance of the coherency management activities.

Abstract: An apparatus for accessing a banked embedded dynamic random access memory device is disclosed. The apparatus for accessing a banked embedded dynamic random access memory (DRAM) device comprises a general functional control logic and a bank RAS controller. The general functional control logic is coupled to each bank of the banked embedded DRAM device. Coupled to the general functional control logic, the bank RAS controller includes a rotating shift register having multiple bits. Each bit within the rotating shift register corresponds to each bank of the banked embedded DRAM device. As such, a first value within a bit of the rotating shift register allows accesses to an associated bank of the banked embedded DRAM device, and a second value within a bit of the rotating shift register denies accesses to an associated bank of the banked embedded DRAM device.

Abstract: An apparatus for allocating data usage in an embedded dynamic random access memory (DRAM) device is disclosed. The apparatus for allocating data usages within an embedded dynamic random access memory (DRAM) device comprises a control analysis circuit, a data/command flow circuit, and a partition management control. The control analysis circuit generates an allocation signal in response to processing performances of a processor. Coupled to an embedded DRAM device, the data/command flow circuit controls data flow from the processor to the embedded DRAM device. The partition management control, coupled to the control analysis circuit, partitions the embedded DRAM device into a first partition and a second partition. The data stored in the first partition are different from the data stored in the second partition according to their respective usage. The allocation percentages of the first and second partitions are dynamically allocated by the allocation signal from the control analysis circuit.

Abstract: Disclosed is a method and memory subsystem that allows for speculative issuance of reads to a DRAM array to provide efficient utilization of the data out bus and faster read response for accesses to a single DRAM array. Two read requests are issued simultaneously to a first and second DRAM in the memory subsystem, respectively. Data issued from the first DRAM is immediately placed on the data out bus, while data issued from the second DRAM is held in an associated buffer. The processor or memory controller then generates a release signal if the second read is not speculative or is correctly speculated. The release signal is sent to the second DRAM after the first issued data is placed on the bus. The release signal releases the data issued from the second DRAM to the buffer from the buffer on to the data out bus.

Abstract: A multiprocessor computer system in which snoop operations of the caches are synchronized to allow the issuance of a cache operation during a cycle which is selected based on the particular manner in which the caches have been synchronized. Each cache controller is aware of when these synchronized snoop tenures occur, and can target these cycles for certain types of requests that are sensitive to snooper retries, such as kill-type operations. The synchronization may set up a priority scheme for systems with multiple interconnect buses, or may synchronize the refresh cycles of the DRAM memory of the snooper's directory. In another aspect of the invention, windows are created during which a directory will not receive write operations (i.e., the directory is reserved for only read-type operations). The invention may be implemented in a cache hierarchy which provides memory arranged in banks, the banks being similarly synchronized.