Abstract: A cache control device includes an entering unit, a first searching unit, a reading unit, a second searching unit, and a rewriting unit. The entering unit alternately enters, into a pipeline, a load request for reading a directory received from a processor and a store request for rewriting a directory received from the processor. When the first searching unit determines that the directory targeted by the load request is present in the first cache memory or the second cache memory, the reading unit reads the directory from the cache memory in which the directory is present. When the second searching unit determines that the directory targeted by the store request is present in the first cache memory, the rewriting unit rewrites the directory that is stored in the first cache memory.

Abstract: A directory cache control device includes a cache unit, a detection unit, a holding unit, a determination unit, and a control unit. The cache unit caches a directory indicating an information processing apparatus caching information that is stored in a memory. The detection unit detects an error in the directory in the cache unit. The holding unit holds a memory address of the memory where information associated with the directory where the error is detected is stored. The determination unit determines whether a memory address that is a target of the read request and the address that is being held by the holding unit match each other or not. The control unit controls coherency of the information that is a target of the read request, based on a directory of the information that is the target of the read request.

Abstract: A transmission/reception device includes a transmission device that divides a plurality of connection lines into a plurality of groups, determines corresponding connection lines in the plurality of groups, determines a correspondence between test pattern and the connection line, and outputs the test pattern to the plurality of connection lines based on the correspondence between the test pattern and the connection line, and a reception device that receives the test pattern from the transmission device, compares bits in a same position of the test pattern received through a corresponding connection line in the plurality of groups based on the correspondence between the test pattern and the connection line, and generates erroneous connection line information indicating an erroneous connection line as a connection line in which an error has occurred in the plurality of connection lines based on a result of the comparison.

Abstract: A cache memory device including a cache memory that includes a plurality of entries and includes at least one block including data and a status representing a status of the data for each entry and a control unit that performs replacement of the data on each block of the cache memory, wherein the control unit includes a counter that counts the number of replacements by which the data is replaced in each entry for each entry and a switching unit that switches a replacement scheme of the data according to the number of replacements.

Abstract: To prevent a decrease in performance of controlling a snoop tag. A queue is stored with REPLACE target WAY information and an index as an entry associated with a REPLACE request received from a processor, the index stored in the queue is compared with an index of a subsequent READ request, and, as a result of the comparison, a process based on the index-coincident READ request is executed with respect to the snoop tag corresponding to a content of a cache memory of the processor. Further, the REPLACE target WAY information of the READ request is replaced with the WAY information in the index-coincident entry within the queue.

Abstract: A verification device includes a data verifying unit that verifies whether data in a packet has an error using a first or a second verification mode, a packet generating unit that generates a packet in accordance with a first packet generation mode or a second packet generation mode respectively corresponding to the first and the second verification modes, a failure monitoring unit that monitors a failure of a transmission line that requires a switching of the verification mode, a switching packet transmitting unit that transmits to a destination device, a switching packet for informing the switching of the verification mode used by the data verifying unit when the failure monitoring unit detects a failure or a removal of a failure, a generation mode switching unit that switches the generation mode, and a verification mode switching unit that switches the verification mode to the one informed by the switching packet.

Abstract: A method of updating a routing table includes: receiving, from an issue-source node, a write packet that includes update data for updating the routing table; attempting to recognize, based upon contents of the write packet, a partition in which the issue-source node is included; determining whether to permit updating the routing table based upon (1) whether the partition including the source node is recognized and (2) whether port information and partition information in the update data are stored in the routing table; and updating the routing table when updating is permitted.

Abstract: A method of switching internal settings in an information processing apparatus including a plurality of processors, a crossbar switch connected to the plurality of processors and having a first routing table and a second routing table used for routing between the plurality of processors and an external apparatus, and a management unit managing the plurality of processors. The method includes performing, by the processors, data communication with the external apparatus using the first routing table, updating, by the management unit, configuration information in the second routing table when a configuration of the information processing apparatus is changed, instructing, by the management unit, any one of the processors to switch the updated second routing table and the first routing table, and switching, by the processor instructed by the management unit, a routing table to be used for the data communication from the first routing table to the updated second routing table.

Abstract: A northbridge, when detecting a synchronization break of a redundant CPU, stops the operation of an abnormal CPU bus where an error has occurred and the firmware in a firmware hub instructs the northbridge to inhibit an external instruction. In addition, the firmware saves the inside information of a normal CPU connected to a normal CPU bus and cache data on a memory and the northbridge issues reset to all CPUs in the home system board. The firmware then restores the inside information of the CPU saved on the memory to all CPUs and instructs the northbridge to cancel the inhibition of the external instruction.

Abstract: A request issued by the CPU is output from the local arbiter by way of the CPU bus and the CPU-issued request queue. The cache replacement request loop-back circuit determines at the loop-back determination circuit whether the outputted request is a cache replacement request or not. A request other than a cache replacement request is output onto the local bus. A cache replacement request is output to the selector and sent to the request handling section when there is no valid request on the global bus.

Abstract: An information processing system includes sets of multiple processors performing processing synchronously. The system includes: a ROM storing a firmware program activating the processors to a synchronized state; a RAM defined by one address map; a firmware copying section copying the firmware program in the ROM to the RAM, on system boot; and a RAM address register storing an address of the RAM and of a copy destination of the firmware program. The system further includes: a RAM address storing section storing the address of the RAM and of the copy destination of the firmware program; a loss-of-synchronism detection section detecting loss of synchronism of the processors; and an address replacing section referring to the RAM address register upon detection of the loss of synchronism, thereby replacing an address for reading the stored firmware program, with the address of the RAM and of the copy destination of the firmware program.

Abstract: A transmission/reception device includes a transmission device that divides a plurality of connection lines into a plurality of groups, determines corresponding connection lines in the plurality of groups, determines a correspondence between test pattern and the connection line, and outputs the test pattern to the plurality of connection lines based on the correspondence between the test pattern and the connection line, and a reception device that receives the test pattern from the transmission device, compares bits in a same position of the test pattern received through a corresponding connection line in the plurality of groups based on the correspondence between the test pattern and the connection line, and generates erroneous connection line information indicating an erroneous connection line as a connection line in which an error has occurred in the plurality of connection lines based on a result of the comparison.

Abstract: An information processing device having two processing units capable of operating in synchronization with each other, includes: a common unit capable of outputting an identical signal to the two processing units; detection units that are respectively provided for the processing units and each detects errors occurred in corresponding processing unit respectively; a comparison unit that compares outputs from the two processing units; and a control unit that controls signals from the processing units to the common unit, based on a detection result of the detection units and a comparison result of the comparison unit, and determines, if errors of an identical type are simultaneously detected by the detection units, that the errors are due to an error of the common unit.

Abstract: A control device managing a plurality of nodes transmitting and receiving data containing an error correcting code, comprises means accepting, when any one of the nodes detects an uncorrectable error from the data containing the error correcting code, a signal transmitted by the node detecting the error, means judging from a record of the detection of a first node, when accepting the signal from a second node receiving data transmitted by the first node, whether or not the first node has detected the uncorrectable error from the data transmitted to the second node, and means stopping, when the first node has detected the uncorrectable error from the data transmitted to the second node, a process attributed to the acceptance of the signal from the second node.

Abstract: A verification device includes a data verifying unit that verifies whether data in a packet has an error using a first or a second verification mode, a packet generating unit that generates a packet in accordance with a first packet generation mode or a second packet generation mode respectively corresponding to the first and the second verification modes, a failure monitoring unit that monitors a failure of a transmission line that requires a switching of the verification mode, a switching packet transmitting unit that transmits to a destination device, a switching packet for informing the switching of the verification mode used by the data verifying unit when the failure monitoring unit detects a failure or a removal of a failure, a generation mode switching unit that switches the generation mode, and a verification mode switching unit that switches the verification mode to the one informed by the switching packet.

Abstract: A method of updating a routing table includes: receiving, from an issue-source node, a write packet that includes update data for updating the routing table; attempting to recognize, based upon contents of the write packet, a partition in which the issue-source node is included; determining whether to permit updating the routing table based upon (1) whether the partition including the source node is recognized and (2) whether port information and partition information in the update data are stored in the routing table; and updating the routing table when updating is permitted.

Abstract: In a system controller including a CPU-issued request queue having a circuit that processes plural requests having identical addresses not to be inputted to the CPU-issued request queue, a latest request other than a cache replace request is retained by an input-request retaining section. Consequently, even if an address of an issued request for cache replace request matches an address of a request retained by the CPU-issued request queue, the issued request for the cache replace request is not retried but is queued in the CPU-issued request queue when the address of the issued request for the cache replace request does not match the entire address retained by the input-request retaining section.

Abstract: In an information processing system loaded with a CPU having cache and a system controller having a copy of a tag of the cache (snoop tag), and the CPU not issuing replacement information about the cache tag, the number of WAYs of the snoop tags in the system controller is larger than the number of WAYs of the cache tags in the CPU to reduce a cache miss rate and suppress the degradation of performance by suppressing excess replacement of the cache tags in the CPU.

Abstract: A semiconductor integrated circuit includes a circuit block connected to an arithmetic processing unit via a bus, a power supply noise data generator which is configured to generate a power supply noise data signal by converting power supply noise generated in power supply voltage of power supply operates the circuit block, an error detector which is configured to detect an error of data outputted from the circuit block to the bus, and a write controller which is configured to associate power supply noise information based on the power supply noise data signal with data on the bus and write the data in a storage unit, and to stop to write the data in response to the detection of the error by the error detector.

Abstract: A cache-status maintaining unit stores address information of data stored in each entry of a cache memory, and maintains a status of each entry as any one of “strongly modified”, “weakly modified”, “shared”, and “Invalid”. A data-fetching-procedure selecting unit selects, upon receiving a data read request, at least one data fetching procedure based on the address information and the status. A read-data delivering unit selects latest data from among the data fetched, and delivers the latest data to a processor that issued the data read request. A cache-status updating unit updates, when registering the address information of the data, updates the status of the entry based on a type of the data read request.