Abstract: A method an apparatus for interface failure survivability using error correction provides operation of an interface when a number of bits of the interface less than or equal to available error correction depth are present. Initialization tests are used to determine whether the interface errors due to failed interconnects or circuits can be corrected, or whether the interface must be disabled. Subsequent alignment at initialization or during operation idle periods may be disabled for any failed bits. The failed bit indications are determined and maintained in hardware, and used to bypass subsequent calibrations that could otherwise corrupt the interface. A fault indication specifying total failure may be generated and used to shut down the interface and/or connected subsystem in response to an uncorrectable condition and request immediate repair. A second fault indication specifying correctable failure may be generated and used to indicate a need for eventual repair.

Abstract: A data processing system that provides non-disruptive, hot-plug functionality for several major hardware components, namely processors, memory and input/output (I/O) channels. The data processing system comprises an original processor, original memory and an original I/O channel each interconnect via an interconnect fabric. The data processing system also comprises a service element and an operating system (OS). The interconnect fabric comprises wiring and hardware and software logic components that enable both the hot-plug addition (or removal) of additional processors, memory and I/O channels and the on-the-fly re-configuration features required to support the various expansions or removals of the additional components. The various components are added without disrupting the processing of the existing components and become immediately available for utilization within the enhanced system.

Abstract: A data processing system that provides hot-plug add and remove functionality for individual, hot-pluggable components without disrupting current operations of the overall processing system. The processing system includes an interconnect fabric that includes hot plug connector at which an external hot-pluggable component can be coupled to the data processing system and logic components include configuration logic and routing and operating logic. When a hot-pluggable component is connected to the hot plug connector, the service element automatically detects the connection and selects the correct configuration file for the extended system. Once the configuration file is loaded and the system checks of the new element indicates the new element is ready for integration, the new element is integrated into the existing system, and the OS allocates workload to the new element. From a customer perspective, the entire process thus occurs without powering down or disrupting the operation of the existing element.

Abstract: A microprocessor includes a functional block having dynamic power savings circuitry, a functional block control circuit, and a thermal control unit. The functional block control circuits are capable of altering performance characteristics of their associated functional blocks automatically upon detecting an over temperature condition. The thermal control unit receives an over-temperature signal indicating a processor temperature exceeding a threshold and invokes the one or more of the functional block control units in response to the signal. The functional block control units respond to signals from the thermal control unit by reducing processor activity, slowing processor performance, or both. The reduced activity that results causes the dynamic power saving circuitry to engage. The functional block control units can throttle performance by numerous means including reducing the exploitable parallelism within the processor, suspending out-of-order execution, reducing effective resource size, and the like.

Abstract: A method and logical apparatus for managing resource redistribution within a simultaneous multi-threaded (SMT) processor provides a mechanism for redistributing resources between one thread during single-threaded execution and multiple threads during multi-threaded execution. The processor receives an instruction specifying a transition from a single-threaded to a multi-threaded mode or vice-versa and halts execution of all threads executing on the processor. Internal control logic controls a sequence of events that ends instruction prefetching, queue flushing, interrupt processing and maintenance operations and waits for operation of the processor to complete for instructions that are in process. The internal control logic then signals the resources to reallocate the resources to a single-thread if the transition is to single-threaded mode by merging partitions within the resources, or to partition themselves among the threads of the transition is to multi-threaded mode.

Abstract: A method and apparatus for sending thread-execution-state-sensitive supervisory commands to a simultaneous multi-threaded processor provides a mechanism for sending supervisory commands that must be executed for only live threads. The commands may be sent from a service processor or another primary processor in the system or may be supplied by the processor itself through supervisory software control. Since the state of execution of one or more threads may change dynamically within a processor core, an external processor will not know the thread execution state at the time the command operates. The method and apparatus provide a command set and logic that supports selective execution of particular commands directed at “alive” threads (or threads in some other determinable execution state), whereby the command is performed only on resources and/or execution units depending on the actual state of thread execution when the command operates within the processor.

Abstract: A method and logical apparatus for managing thread execution within a simultaneous multi-threaded (SMT) processor provides a mechanism for switching between single-threaded and multi-threaded execution. The processor receives an instruction specifying a transition from a single-threaded to a multi-threaded mode or vice-versa and halts execution of all threads executing on the processor. Internal control logic controls a sequence of events that ends instruction prefetching, dispatch of new instructions, interrupt processing and maintenance operations and waits for operation of the processor to complete for instructions that are in process.

Abstract: A method of communicating between processing units on different integrated circuit chips in a multi-processor computer system by issuing a command from a source processing unit to a destination processing unit, receiving the command at the destination processing unit while the destination processing unit is processing program instructions, and accessing registers in clock-controlled components of the destination processing unit without interrupting processing of the program instructions by the destination processing unit. The access may be a read from status or mode registers of the destination processing unit, or write to control or mode registers. Many processing units can be interconnected in a ring topology, and the access command can be passed from the source processing unit through several other processing units before reaching the destination processing unit.

Abstract: An embeddable method and apparatus for functional pattern testing of repeatable program instruction-driven logic circuits via signal signature generation provides an improved mechanism for functional testing of integrated circuits. The apparatus may be embedded within a processor having an exerciser program loaded within an internal cache and includes one or more multiple input shift registers (MISR) coupled to a set of selected internal signal points within functional blocks of the integrated circuit for collecting a signature in response to state changes of the internal signal points caused by execution of the exerciser program. The signature is compared to a known good signature to generate pass/fail or diagnostic information during design/mask evaluation, manufacturing testing, and/or as a screening test during diagnostic boot in a production environment.

Abstract: An apparatus for performing imprecise bus tracing in a distributed memory symmetric multiprocessor system is disclosed. The apparatus includes a bus trace macro (BTM) module that can control the snoop traffic seen by one or more of the memory controllers in the data processing system and utilize a local memory attached to the memory controller for storing trace records. After the BTM module is enabled for tracing operations, the BTM module snoops transactions on the interconnect and packs information contained within these transactions into a block of data of a size that matches the write buffers within the memory controller. In addition, the BTM module also includes a dropped record counter for counting the number of address transactions that were not converted to trace records because all the write buffers were completely full. After an occurence of the write buffers full condition, a time stamp trace record is inserted before a new trace record can be written.

Abstract: A trace array for recording states of signals includes N-storage locations for k trace signals. In the write mode, an address generator combines the outputs of an event signal counter and a cycle clock counter to generate trace array addresses. A start code is written each time an event signal occurs and event addresses are saved. Recording is stopped by a stop signal and the stop address is saved. A compression code and time stamp code are written when no state changes occur in any trace signals at the cycle clock times to compress recorded trace signal data. An output processor reads out stored states of the trace signals and uses the start codes, event addresses, stop address, compression code and time stamp to reconstruct the original trace signal sequences for analysis.

Abstract: An integrated circuit having a temperature sensitive circuit (TSC) to generate a signal indicative of the substrate temperature near the TSC. The integrated circuit has circuitry configured to receive a TSC signal from at least one TSC and to convert the TSC signal to a signal indicative of the integrated circuit's temperature. The thermal control circuit compares the integrated circuit temperature to a threshold and produces a corrective action signal when the temperature exceeds the threshold. The corrective action signal is provided to corrective action circuitry preferably configured to modify the operation of the IC to reduce the IC temperature in proximity to the corresponding TSC.

Abstract: A writeable K by P trace array with parallel inputs and outputs is incorporated within a VLSI integrated circuit. The trace array is partitioned into N sub-arrays each sub-array having M=P/N entries for the K input signals. Logic circuitry couples selected K input signals to the trace array so that M states of the K input signals may be stored in each of the N sub-arrays. A start signal enables storing of states of the K input signals at time intervals determined by a clock. The clock is counted in a counter and when M is reached the counter is reset back to an initial state. New states of the K input signals written over old states until a pre-determined event signals occurs, at which time storing the sub-array is stopped saving the stored states of the logic inputs. Writing is simultaneously started in a succeeding sub-array in the same fashion until another event signal occurs.

Abstract: A method and apparatus for harvesting problematic code sections that may cause a hang condition based on a hardware design flaw is presented. Monitoring is performed to detect a hang condition. Responsive to detecting a hang condition, steps are employed by hardware and/or software to recover from a hang condition, such as flushing instructions dispatched to the plurality of execution units. Upon successful completion of hang recovery, a debug interrupt is injected, causing a debug interrupt handler to be immediately involved before the resumption of normal execution. The debug interrupt handler may then harvest problematic code sections in the undisturbed execution error that may have caused the hang condition.

Abstract: A method, program and system for electrical shorts testing are provided. The invention comprises setting any chips to be tested to drive 0's on their drive interfaces, and setting all receive interfaces on the chips to receive 0's and log any failures. Next a single receive interface is selected for testing. A hardware shift register is associated with each drive side interface, wherein each bit of the register is connected to an off-chip driver on the interface. This hardware shift register for the selected interface is then set to all 0's, and the first bit of the shift register is loaded to a 1. The invention then performs a pause count. After this count, the 1 is shifted to the next bit in the register and another pause count is performed. This process is repeated until the 1 is walked completely through the register and all pins on the interface have been tested. The walking 1 test is then repeated for any additional interfaces that require testing.

Abstract: A trace array having M entries with corresponding M addresses is used to store the states of input signals. The M addresses of the trace array are sequenced with a counter that counts a clock beginning at a starting count and counting to an ending count. If the ending count is exceeded, the counter starts over at the starting count. The counter outputs are decoded to addresses of the trace array. An event signal is generated on the occurrence of an operation of interest and the counter is started and stopped in response to sequences of the event signals, thus starting and stopping the recording of states of the input signals in the trace array. When an error or particular condition signal occurs, traces corresponding to the input signals are saved in the trace array. A start signal enables tracing and event logic generates event sequence signals which alternately start and stop the recording of traces.

Abstract: A method and apparatus for scanning the test and diagnostics control logic on a chip maintains the state of the chip in a frozen state as the scan of the normally free-running logic occurs. The chip is configured to select the test and diagnostics control logic if an instruction to scan the test and free-running logic is in the instruction register. A scan switch is configured to pass the scan output from the free-running logic to the test data output on the chip. Test data input is passed to the test and diagnostics control logic through the use of the scan select, as with the other logic units. The control interface is configured to feed a stop control and scan control signal back to the free-running logic under control of stop enable and scan enable signals. Outputs are forced to an electrically safe value by shadowing the driver control register, which controls the functional output.

Abstract: A method and apparatus for providing cooperative fault recovery between an operating system and a service processor allows fault detection and recovery capability utilizing a service processor while an operating system is running on a main processor. A register is provided within the main processor component for sending information to the service processor. An attention signal is provided to the service processor to indicate that the operating system has written information to the register and is requesting the service processor's attention. A JTAG standard interface is used to access the register from the service processor and an interrupt is provided to the operating system to indicate that the service processor has written information to the register and is requesting the operating system's attention.

Abstract: The system and method of the present invention is embodied in a multi-state on-chip logic analyzer that is preferably integrated into a VLSI circuit. In general, the logic analyzer is preferably coupled to a multilevel trace array for storing event trace data generated by the logic analyzer. Input and output logic coupled to both the trace array and the logic analyzer allows reading or writing from or to the trace array, and programming of trigger and condition criteria for transitioning states within the logic analyzer. The logic analyzer has the capability match one or more programmable trigger events to satisfy one or more programmable conditions. Further, the logic analyzer preferably has the capability to initialize programmable conditions in desired states, and to store event trace data in an on-chip array for trace data reconstruction and analysis.

Abstract: A method and apparatus for patching a problematic instruction within a pipelined processor in a data processing system is presented. A plurality of instructions are fetched, and the plurality of instructions are matched against at least one match condition to generate a matched instruction. The match conditions may include matching the opcode of an instruction, the pre-decode bits of an instruction, a type of instruction, or other conditions. A matched instruction may be marked using a match bit that accompanies the instruction through the instruction pipeline. The matched instruction is then replaced with an internal opcode or internal instruction that causes the instruction scheduling unit to take a special software interrupt. The problematic instruction is then patched through the execution of a set of instructions that cause the desired logical operation of the problematic instruction.