摘要:
A system and method in which the receiving chip separately latches each half of the data received from the double data rate bus. Each half is launched as soon as it is available; one on the normal chip cycle time and the other is launched from a Master (L1) latch a half cycle into the normal chip cycle time. The first launched half of the data proceeds through the chip along its standard design chip path to be captured by the chips driving interface latch and launched again after one cycle of latency on the chip. The second half of the data proceeds through the chip one half cycle behind the first half, and is latched a half clock cycle later part way through the path into a Slave (L2) latch. On the next edge of the local clock, the data then continues from the L2 latch to the driving double data rate interface. This allows a half cycle set up time for the second half of the data so that it can be launched again, maintaining a one-cycle time on the chip.
摘要:
Systems, methods and computer program products for providing a nested two-bit symbol bus error correcting code. Methods include constructing a nested error correcting code (ECC) scheme. The method includes receiving a Hamming distance n code. A symbol correcting code H-matrix is created by iteratively adding rows of H-matrix bits on a symbol column basis such that the symbol correcting code H-matrix describes a symbol correcting code, and the Hamming distance n code is preserved as a subset of the symbol correcting code H-matrix.
摘要:
A system for processing errors in a processor comprising, an error counter, a pass counter, and a processing portion operative to determine whether a first error is active, increment an error counter responsive to determining that the first error is active, increment the pass counter responsive to determining that all errors have been checked, and clear the error counter responsive to determining that the pass counter is greater than or equal to a pass count threshold value.
摘要:
Methods and means of error correction code (ECC) debugging may comprise detecting whether a bit error has occurred; determining which bit or bits were in error; and using the bit error information for debug. The method may further comprise comparing ECC syndromes against one or more ECC syndrome patterns. The method may allow for accumulating bit error information, comparing error bit failures against a pattern, trapping data, counting errors, determining pick/drop information, or stopping the machine for debug.
摘要:
Disclosed is a method and apparatus for arbitration between multiple pipelines over shared resources for an SMP computer system. The computer includes logic to defer arbitration until later in the pipeline to help reduce latency to each pipeline. Also, introduced is the concept of retry tags for better priority to avoid lock-out. The system also includes round-robin tokens to manage rejected requests to allow better fairness on conflicts. While the processing logic employed specifically applies to cross-interrogation, the logic can be extended to other common resources. The illustrated SMP computer system also has self-correcting logic to maintain good round-robin tokens.
摘要:
A method of calibrating an elastic interface is provided to automatically achieve a minimal cycle delay through the interface. An existing self-alignment interface (i.e. elastic interface) is used to de-skew within a cycle and stage the data to have it arrive on a given, programmed target cycle. However, this target cycle must be calculated in advance and may be larger than it needs to be, causing more latency on the interface. This method is used to determine the earliest target cycle (with or without additional guard-band). This target cycle is used to adjust the interface automatically to achieve this earliest target cycle. The determination of earliest target cycle can be done once, continuously, or using a sample window. The method also can be used for interfaces that have frequency multipliers or phase shifts at its boundaries.
摘要:
Uncorrectable errors are detected during the transmission of a data word according to an error correction code. Then, any address faults are identified from among the detected uncorrectable errors. In addition, address faults as well as uncorrectable memory data failures are detected from among the detected uncorrectable errors. Furthermore, address parity bits are not required to be stored to memory.
摘要:
Error detection and correction circuitry, optimized to reduce the time required to correct single errors and to detect the presence of uncorrectable errors, uses an optimized H-Matrix and provides reduced logic circuitry. Correctable error syndromes are defined as comprising an odd number of ones and an uncorrectable-error detection circuit generates an uncorrectable-error indication when an even number of ones are detected. The correctable-error syndromes are defined as having a predefined combination of ones and zeros in each of a set of corresponding bit positions and different combinations of ones and zeros in other bit positions. An error syndrome comprising only zeros is designated as indicative of a no error condition. Logic circuitry is provided which implements the error detection and correction circuitry with a reduced set of logic gates.
摘要:
A clock tuning system and method for a data processing system with enhanced timing failure diagnostics and unlayering capabilities. Both common and individual phase adjusting capabilities ensure programmable tuning of clock pulses distributed throughout a computer system, thereby facilitating isolation of timing margin failure to specific clock signals or enhancing system performance by shifting timing margin between logic paths. Both single-clock and dual-clock data processing are discussed, as well as clock tuning embodiments for each.
摘要:
Providing homogeneous recovery in a redundant memory system that includes a memory controller, a plurality of memory channels in communication with the memory controller, an error detection code mechanism configured for detecting a failing memory channel, and an error recovery mechanism. The error recovery mechanism is configured for receiving notification of the failing memory channel, for blocking off new operations from starting on the memory channels, for completing any pending operations on the memory channels, for performing a recovery operation on the memory channels and for starting the new operations on at least a first subset of the memory channels. The memory system is capable of operating with the first subset of the memory channels.