Abstract: Concurrent servicing of a first cable of a cable pair while a second cable of the cable pair remains operational improves multi-processor computer system availability and serviceability. A pair of processing chips in different processing drawers may continue operation by way of the second cable while the first cable is degraded or serviced. Upon the servicing of the first cable, the serviced cable may transition to a fully operational state with no interruptions to the operations between the processing drawers by way of the second cable. Since cable faults are typically more common than processing chip or processing drawer faults, identification of cable faults and the ability to maintain operations of the processing drawers connected therewith is increasingly important.

Abstract: A memory controller stores each of a plurality of data blocks encoded by error correction code (ECC) across multiple channels of a redundant memory system. Based on receiving, from the memory system, channel data of a fetch operation requesting a data block, the memory controller decodes the channel data and concurrently generates a predicted channel mark based on tests of channel-induced syndromes generated from the channel data. The predicted channel mark identifies a marked channel among the multiple channels as a likely source of data errors. The memory controller determines whether the decoding detects an uncorrectable error in the channel data and, based on determining the decoding detects an uncorrectable error in the channel data, re-reads channel data corresponding to the data block and corrects the re-read channel data by excluding, from decoding, channel data received from the marked channel.

Abstract: Embodiments of the invention are directed to a computer-implemented method of operating a data transmission system. The data transmission system includes a transmitter and a receiver. The computer-implemented method includes using the transmitter to send serialized data from the transmitter through a plurality of lanes to the receiver. The transmitter sends the serialized data at a first serialization ratio. The receiver is configured to receive and load the serialized data at a second deserialization ratio, wherein the first serialization ration is greater than the second deserialization ratio.

Abstract: Concurrent servicing of a first cable of a cable pair while a second cable of the cable pair remains operational improves multi-processor computer system availability and serviceability. A pair of processing chips in different processing drawers may continue operation by way of the second cable while the first cable is degraded or serviced. Upon the servicing of the first cable, the serviced cable may transition to a fully operational state with no interruptions to the operations between the processing drawers by way of the second cable. Since cable faults are typically more common than processing chip or processing drawer faults, identification of cable faults and the ability to maintain operations of the processing drawers connected therewith is increasingly important.

Abstract: A computer-implemented method includes using a transmitter to send data from the transmitter through a plurality of lanes to a receiver using a synchronous operation mode that includes sending the data from the transmitter through the plurality of lanes to the receiver in a synchronous transmission manner that relies on an alignment between a transmitter clock frequency and a receiver clock frequency. A synchronous operation performance analysis (SOPA) is performed during the synchronous operation mode. A switch from the synchronous operation mode to an asynchronous operation mode is made based on a result of performing the SOPA. The asynchronous operation mode includes sending the data from the transmitter through the plurality of lanes to the receiver without requiring alignment between the transmitter clock frequency and the receiver clock frequency.

Abstract: Embodiments of the invention are directed to a computer-implemented method of operating a data transmission system. The data transmission system includes a transmitter and a receiver. The computer-implemented method includes using the transmitter to send serialized data from the transmitter through a plurality of lanes to the receiver. The transmitter sends the serialized data at a first serialization ratio. The receiver is configured to receive and load the serialized data at a second deserialization ratio, wherein the first serialization ration is greater than the second deserialization ratio.

Abstract: A computer-implemented method includes using a transmitter to send data from the transmitter through a plurality of lanes to a receiver using a synchronous operation mode that includes sending the data from the transmitter through the plurality of lanes to the receiver in a synchronous transmission manner that relies on an alignment between a transmitter clock frequency and a receiver clock frequency. A synchronous operation performance analysis (SOPA) is performed during the synchronous operation mode. A switch from the synchronous operation mode to an asynchronous operation mode is made based on a result of performing the SOPA. The asynchronous operation mode includes sending the data from the transmitter through the plurality of lanes to the receiver without requiring alignment between the transmitter clock frequency and the receiver clock frequency.

Abstract: A computer-implemented method includes fetching, by a controller, data using a plurality of memory channels of a memory system. The method further includes detecting, by the controller, that a first memory channel of the plurality of memory channels has not returned data. The method further includes marking, by the controller, the first memory channel from the plurality of memory channels as unavailable. The method further includes, in response to a fetch, reconstructing, by the controller, fetch data based on data received from all memory channels other than the first memory channel.

Abstract: A computer-implemented method includes refreshing a set of memory channels in a memory system substantially simultaneously, each memory channel refreshing a rank that is distinct from each of the other ranks being refreshed. Further, the method includes marking a memory channel from the set of memory channels as being unavailable for the rank being refreshed in the memory channel. In one or more examples, the method further includes blocking a fetch command to the memory channel for the rank being refreshed in the memory channel.

Abstract: A computer-implemented method for memory macro disablement in a cache memory includes identifying a defective portion of a memory macro of a cache memory bank. The method includes iteratively testing each line of the memory macro, the testing including attempting at least one write operation at each line of the memory macro. The method further includes determining that an error occurred during the testing. The method further includes, in response to determining the memory macro as being defective, disabling write operations for a portion of the cache memory bank that includes the memory macro by generating a logical mask that includes at least bits comprising a compartment bit, and read address bits.

Abstract: A computer-implemented method includes fetching, by a controller, data using a plurality of memory channels of a memory system. The method further includes detecting, by the controller, that a first memory channel of the plurality of memory channels has not returned data. The method further includes marking, by the controller, the first memory channel from the plurality of memory channels as unavailable. The method further includes, in response to a fetch, reconstructing, by the controller, fetch data based on data received from all memory channels other than the first memory channel.

Abstract: A computer-implemented method includes fetching, by a controller, data using a plurality of memory channels of a memory system. The method further includes detecting, by the controller, that a first memory channel of the plurality of memory channels has not returned data. The method further includes marking, by the controller, the first memory channel from the plurality of memory channels as unavailable. The method further includes, in response to a fetch, reconstructing, by the controller, fetch data based on data received from all memory channels other than the first memory channel.

Abstract: A computer-implemented method includes fetching, by a controller, data using a plurality of memory channels of a memory system. The method further includes detecting, by the controller, that a first memory channel of the plurality of memory channels has not returned data. The method further includes marking, by the controller, the first memory channel from the plurality of memory channels as unavailable. The method further includes, in response to a fetch, reconstructing, by the controller, fetch data based on data received from all memory channels other than the first memory channel.

Abstract: A computer-implemented method includes refreshing a set of memory channels in a memory system substantially simultaneously, each memory channel refreshing a rank that is distinct from each of the other ranks being refreshed. Further, the method includes marking a memory channel from the set of memory channels as being unavailable for the rank being refreshed in the memory channel. In one or more examples, the method further includes blocking a fetch command to the memory channel for the rank being refreshed in the memory channel.

Abstract: A computer-implemented method for memory macro disablement in a cache memory includes identifying a defective portion of a memory macro of a cache memory bank. The method includes iteratively testing each line of the memory macro, the testing including attempting at least one write operation at each line of the memory macro. The method further includes determining that an error occurred during the testing. The method further includes, in response to determining the memory macro as being defective, disabling write operations for a portion of the cache memory bank that includes the memory macro by generating a logical mask that includes at least bits comprising a compartment bit, and read address bits.

Abstract: Dynamic routing of data to multiple processor complexes. PCI address space is subdivided among a plurality of processor complexes. Translation table entries at each processor complex determine which processor complex is to receive a DMA transfer, thereby enabling routing of DMA data to one I/O hub node while accessing translation table entries at another I/O hub node. Further, interrupt requests may be dynamically routed to multiple processor complexes.

Abstract: A processor system includes an I/O bus to host bridge in which I/O address translation elements are shared across multiple I/O bus bridges. A TCE manager is provided for retaining in cache a TCE entry associated with a discarded channel for association with a new channel responsive to a subsequent read request for a memory page referenced by the TCE entry.

Abstract: A coherency controller for configurable caches. A base microprocessor design accommodates system configurations both with and without L2 cache tag and data arrays installed. Second level cache control logic exists within the microprocessor chip, and when the external second level cache tag and data arrays are removed their inputs to the microprocessor are tied to an inactive state. A configuration switch is set in the second level cache controller that causes snoop requests from a system bus to get reflected onto a first level cache snooping path. The first level cache status is then fed back to the second level cache controller, in a manner consistent with the timing required for support of a second level cache search, and fed into the second level cache status signal generation logic, effectively making the second level cache controller believe that the second level cache still exists for snooping.

Abstract: A cache system is provided for accessing set associative caches with no increase in critical path delay, for reducing the latency penalty for cache accesses, for reducing snoop busy time, and for responding to MRU misses and cache misses. A two level cache subsystem including an L1 cache and an L2 cache is provided. A cache directory is accessed for a second snoop request while a directory access from a first snoop request is being evaluated. During a REQUEST stage, a directory access snoop to the directory of the L1 cache is requested; and responsive thereto, during a SNOOP stage, the directory is accessed; during an ACCESS stage, the cache arrays are accessed while processing results from the SNOOP stage. If multiple data transfers are required out of the L1 cache, a pipeline hold is issued to the REQUEST and SNOOP stages, and the ACCESS stage is repeated. During a FLUSH stage, cache data read from the L1 cache during the ACCESS stage is sent to the L2 cache.

Abstract: A cache system provides for accessing set associative caches with no increase in critical path delay, for reducing the latency penalty for cache accesses and for responding to slot MRU misses and cache misses. An N-way set associative cache is provided, each set of said cache including an SRAM array macro having a memory element, an internal SRAM data register, and a read enable signal line. Read enable is generated as the NOR of slot miss and cache miss signals, and the internal SRAM data register is responsive to the slot miss signal for registering data output during a first cycle for use in a next following cycle.