Abstract: A cache-based system is adapted for dynamic cache partitioning. A cache is partitioned into a plurality of cache partitions for a plurality of entities. Each cache partition can be assigned as a private cache for a different entity. If a first cache partition satisfying a first predetermined cache partition condition and a second cache partition satisfying a second predetermined cache partition condition are detected, then the size of the first cache partition is increased by a predetermined segment and the size of the second cache partition is decreased by the predetermined segment. An entity can perform cacheline replacement exclusively in its assigned cache partition, and also be capable of reading any cache partition.

Abstract: A computer system with high-speed memory devices includes error checking logic that monitors the number and/or frequency of memory errors. The number and/or frequency of soft memory errors is provided to control logic in a memory controller, which intelligently modifies the frequency of memory calibration cycles based on the detected memory errors. Thus, in response to an unacceptable number of memory errors, the memory controller may increase the frequency of calibration cycles. The memory controller may include error checking logic that monitors memory errors on multiple memory channels, if multiple memory channel are provided, to enable the memory controller to modify calibration frequency on a channel-by-channel basis.

Abstract: A computer system with high-speed memory devices includes one or more temperature sensors and/or environmental sensors that monitor environmental parameters that may affect the operation of the high-speed memory devices. The sensor values are provided to control logic in a memory controller that can intelligently modify the operation of the memory devices in response to changing environmental conditions. Thus, in response to deteriorating environmental conditions, the memory controller may increase the frequency of calibration cycles. The sensors may be provided on multiple channels, if the memory system is configured with multiple channels, or may be individually associated with memory devices. In addition, the memory controller also monitors the expected remaining life of the memory devices, and the number of errors occurring in the memory devices, and based on these parameters, may change the frequency of the calibration cycles.

Abstract: A computer system having a main memory and a cache memory, the computer system uses portions of the cache memory to store information from defective main memory locations until the main memory can be repaired. The address space of the main memory is always maintained by substituting cache-lines of cache memory for the defective main memory locations. A fail-over memory status bit in the cache memory controller indicates when a cache line of the cache memory contains fail-over information from the defective or failing main memory so that that cache-line will not be written over by a cache replacement algorithm. When the fail-over status bit is set, the contents of the fail-over memory location(s) remains in the cache-line and all memory reads and writes are directed to only that cache-line of the cache memory and not the main memory for the fail-over memory location(s).

Abstract: A computer system includes a power supply coupled to a control logic, the power supply including a power_good output signal and Power output lines. The power_good signal notifies the control logic when the Power output lines have stabilized. The computer system also includes a plurality of voltage regulator modules (“VRM”) coupled to the control logic, wherein each VRM receives a power good signal from the control logic. A plurality of processors is also present in the computer system, each of the processors coupled to a VRM. Each of the VRMs transmits voltage to a processor to power-on the processor. Each VRM also transmits to its processor and to the control logic a voltage regulator module power good (“VRMP_G”) signal. The control logic includes means to control the sequential power-on of the processors so as to reduce the current sourcing requirements of the power supply and eliminate power supply surges.

Abstract: A computer system with high-speed memory devices includes one or more temperature sensors and/or environmental sensors that monitor environmental parameters that may affect the operation of the high-speed memory devices. The sensor values are provided to control logic in a memory controller that can intelligently modify the operation of the memory devices in response to changing environmental conditions. Thus, in response to deteriorating environmental conditions, the memory controller may increase the frequency of calibration cycles. The sensors may be provided on multiple channels, if the memory system is configured with multiple channels, or may be individually associated with memory devices. In addition, the memory controller also monitors the expected remaining life of the memory devices, and the number of errors occurring in the memory devices, and based on these parameters, may change the frequency of the calibration cycles.

Abstract: A computer system includes a memory controller that controls and formats transactions with a high speed memory. The memory controller includes a read queue, a write queue, and various other queues in which memory transactions may be stored pending execution. The memory controller periodically executes calibration cycles, such as temperature calibration cycles to the memory to reduce memory errors. The temperature calibration cycles may include an idle state during which no read transactions can be executed. The memory controller includes arbitration logic that reduces latency by issuing read transaction first. Once reads have been issued, the arbitration logic executes any pending temperature cycles. During the idle period of the calibration cycle, the arbitration logic schedules write transactions, and transactions to memory from other queues and devices, including precharge transactions, row activate transactions, refresh cycles, and other calibration cycles.

Abstract: A computer system with high-speed memory devices includes error checking logic that monitors the number and/or frequency of memory errors. The number and/or frequency of soft memory errors is provided to control logic in a memory controller, which intelligently modifies the frequency of memory calibration cycles based on the detected memory errors. Thus, in response to an unacceptable number of memory errors, the memory controller may increase the frequency of calibration cycles. The memory controller may include error checking logic that monitors memory errors on multiple memory channels, if multiple memory channel are provided, to enable the memory controller to modify calibration frequency on a channel-by-channel basis.

Abstract: A computer system with high-speed memory devices includes one or more temperature sensors and/or environmental sensors that monitor environmental parameters that may affect the operation of the high-speed memory devices. The sensor values are provided to a control logic in a memory controller, that can intelligently modify the operation of the memory devices in response to changing environmental conditions. Thus, in response to deteriorating environmental conditions, the memory controller may increase the frequency of calibration cycles, or may throttle down the operating speed of the memory devices, or may place some or all of the memory devices in a low power mode until conditions improve. The sensors may be provided on multiple channels, if the memory system is configured with multiple channels, or may be individually associated with memory devices.

Abstract: A computer system comprises a variety of components transmitting variable-rate heartbeats to a heartbeat monitor, each heartbeat indicating that the component is functioning properly. In addition, selected components serve as proxies by transmitting heartbeats to indicate that another component is functioning properly. In the preferred embodiment, one or more central processing units (CPUs) transmit heartbeats to indicate proper CPU functioning, while a bridge logic device and a network interface card (NIC) transmit heartbeats as proxies for a memory device and an external computer system, respectively. The heartbeat monitor is capable of determining initial heart rates for each component and is further capable of adaptively varying the heart rates thereafter. If the age of the heartbeat sender is relatively young, then a relatively slow heart rate is specified. Faster heart rates are specified for older components.

Abstract: A scheme may be used to remove or replace a processor in a multiprocessor computer without the need for turning the computer off to replace the processor. In this scheme, the bus to which the processor is coupled is identified so that all processors coupled to the bus may be placed in sleep mode. This act does not alter the normal operation of processors that may be coupled to another bus. Once the processors are in sleep mode, the processor may be removed or replaced. Afterward, all processors may be returned to normal operation.

Abstract: A multiprocessor computer includes a fault detection scheme which detects and identifies the failure of one of the processors. Each processor is assigned a write location, which may be a unique register. During normal computer operation, each processor intermittently performs a test and stores the results of the test in the assigned write location. The stored results are compared to expected results, and an error signal is generated if the stored results differ from the expected results to indicate that one of the processors has failed.