Abstract: A memory subsystem that includes segment level sparing. The memory subsystem includes a cascaded interconnect system with segment level sparing. The cascaded interconnect system includes two or more memory assemblies and a memory bus. The memory bus includes multiple segments and the memory assemblies are interconnected via the memory bus.

Abstract: A memory subsystem with a memory bus and a memory assembly. The memory bus includes multiple bitlanes. The memory assembly is in communication with the memory bus and includes instructions for receiving an error code correction (ECC) word in multiple packets via the memory bus. The ECC word includes data bits and ECC bits arranged into multiple multi-bit ECC symbols. Each of the ECC symbols is associated with one of the bitlanes on the memory bus. The memory assembly also includes instructions for utilizing one of the ECC symbols to perform error detection and correction for the bits in the ECC word received via the bitlane associated with the ECC symbol.

Abstract: A system and method for error correction and detection in a memory system. The system includes a memory controller, a plurality of memory modules and a mechanism. The memory modules are in communication with the memory controller and with a plurality of memory devices. The mechanism detects that one of the memory modules has failed possibly coincident with a memory device failure on an other of the memory modules. The mechanism allows the memory system to continue to run unimpaired in the presence of the memory module failure and the memory device failure.

Abstract: A system and method for providing a high fault tolerant memory system. The system includes a memory system having a memory controller, a plurality of memory modules and a mechanism. The plurality of memory modules are in communication with the memory controller and with a plurality of memory devices. The plurality of memory devices include at least one spare memory device for providing memory device sparing capability. The mechanism is for detecting that one of the memory modules has failed possibly coincident with a memory device failure on an other of the memory modules. The mechanism allows the memory system to continue to run unimpaired in the presence of the memory module failure and the possible memory device failure.

Abstract: Systems and methods for improving serviceability of a memory system including a method for identifying a failing memory element in a memory system when two or more modules operate in unison in response to a read request. The method includes receiving syndrome bits and an address associated with an uncorrectable error (UE). In response to a previous correctable error (CE) having occurred, the location of the previous CE is retrieved. The location of the CE specifies a memory device position of the CE. A location of the UE is determined using the location of the previous CE and the syndrome bits of the UE as input. The location of the UE specified a memory device position. A failing memory element associated with the location of the UE is identified.

Abstract: A memory subsystem with a memory bus and a memory assembly. The memory bus includes multiple bitlanes. The memory assembly is in communication with the memory bus and includes instructions for receiving an error code correction (ECC) word in multiple packets via the memory bus. The ECC word includes data bits and ECC bits arranged into multiple multi-bit ECC symbols. Each of the ECC symbols is associated with one of the bitlanes on the memory bus. The memory assembly also includes instructions for utilizing one of the ECC symbols to perform error detection and correction for the bits in the ECC word received via the bitlane associated with the ECC symbol.

Abstract: Systems, method, and computer program products for utilizing a spare lane for additional checkbits. Systems include computer, storage or communications systems with bitlanes for transferring error correcting code (ECC) words in packets over a bus in multiple cycles, a spare bitlane available to the bus, a spared mode and an initial mode. The spared mode is executed when the spare bitlane has been deployed as a replacement bitlane for carrying data for one of the other bitlanes. The initial mode is executed when the spare bitlane has not been deployed as a replacement bitlane. The initial mode includes utilizing the spare bitlane for carrying one or more additional ECC checkbits. The initial mode provides at least one of a more robust error detecting function for the bus than the spared mode and a more robust error correcting function for the bus than the spared mode.

Abstract: Systems, method, and computer program products for providing a nested two-bit symbol bus error correcting code for transfer over a bus in two or more transfers Methods include constructing a nested error correcting code (ECC) scheme. The method includes receiving a Hamming distance n code including original checkbits. A symbol correcting code H-matrix framework is defined including specifying bit positions for the original checkbits and for additional checkbits associated with a symbol correcting code. The bit positions are specified such that the additional checkbits are in bit positions that are transferred over a bus in a transfer subsequent to a first transfer. A symbol correcting code H-matrix is created using the bit positions indicated by the framework by iteratively adding rows of H-matrix bits on a symbol column basis such that the symbol correcting code H-matrix describes the symbol correcting code, and the Hamming distance n code is preserved as a subset of the symbol correcting code H-matrix.

Abstract: 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.

Abstract: Systems, method, and computer program products for providing a nested two-bit symbol bus error correcting code scheme for transfer over a bus in two or more transfers. Methods include constructing a nested error correcting code (ECC) scheme. The method includes receiving a Hamming distance n code including original checkbits. A symbol correcting code H-matrix framework is defined including specifying bit positions for the original checkbits and for additional checkbits associated with a symbol correcting code. The bit positions are specified such that the additional checkbits are in bit positions that are transferred over a bus in a transfer subsequent to a first transfer.

Abstract: Systems, method, and computer program products for providing a nested two-bit symbol bus error correcting code scheme for transfer over a bus in two or more transfers. Methods include constructing a nested error correcting code (ECC) scheme. The method includes receiving a Hamming distance n code including original checkbits. A symbol correcting code H-matrix framework is defined including specifying bit positions for the original checkbits and for additional checkbits associated with a symbol correcting code. The bit positions are specified such that the original checkbits and the additional checkbits are in bit positions that are transferred over a bus in a transfer subsequent to a first transfer.

Abstract: An improved chip sparing system and method of operation are provided in which a failed chip is detected even if there are multiple errors on a single chip and one or more spare chips are provided within the system; and in which spare chips or space chip I/Os are dynamically inserted into the system upon detection of a failed chip or chip I/O without the necessity of shutting down and rebooting the system or even without the necessity of re-initializing the memory.

Abstract: An improved memory card and its use in a computer system is provided. The computer system has a system bus which provides requests from a CPU to a memory controller, which then provides signals to the memory card or module or a memory bus. The memory card is provided with first and second banks of DRAMs, a memory card bus and a DSP. Logic circuitry including a memory card data bus controller provides communication of the DSP with the banks of DRAM chips. Logic circuitry is also provided which can selectively connect the DSP to either the first or second bank of DRAMs and selectively connect the memory bus with the other bank of DRAMs or with both banks of DRAMs. Hence when the CPU is accessing one bank of DRAMS the DSP can access the other bank of DRAMs thus allowing the DSP to function utilizing the bank of DRAMs not being accessed by the memory bus to service the CPU or some I/O device.

Abstract: A memory card adapter and method is provided which can add features or provide functions to a computer system's memory modules without having to replace and discard existing memory modules. An adapter is provided which has electrical contacts that are capable of being plugged into a memory module receiving socket of. a motherboard and a memory module receiving socket capable of receiving and retaining a memory module such as a SIMM. The adapter has logic, circuitry and/or memory chips to add new function to the existing memory module and also has all information and hardware needed for proper interface with the motherboard of the computer system. The present invention can add a variety of function such as parity, error correction code and error correction code on SIMM as well as convert signals which form from the system for use on the SIMM which signals in the form generate by the computer are not compatible with the SIMM.

Abstract: According to the present invention, a computer system and method of operation of the system is provided wherein the computer system has a memory controller which generates first and second RAS signals and Y rows of addresses in memory, and wherein the memory of the system, either as a planar or add-on memory, is configured with Y+1 rows of addresses operable by a single RAS. The system includes logic, preferably which is on an ASIC chip, to convert one of the RAS signals from the memory controller in conjunction with at least one address list to the high order address bit for the memory rows, thus constituting Y+1 rows of addressable space. The logic also generates a master RAS signal when either RAS generated by the memory controller goes active. The logic also provides for a refresh operation of all of the memory locations during a RAS only refresh operation.

Abstract: A serial bus and connection to a device on a computer system through a system memory controller is provided on a memory card having a DSP and a memory bus controller to allow the DSP on the memory card to gain access to the system device without using the system memory bus. The serial bus is a two wire serial bus connecting the device to the DSP through the system memory controller. If more than one memory card is present with DSPs or more than one device is contending for access, the system memory controller or arbitrate the access of each memory card or contending device. In such case the serial bus will signal the system memory controller when it wants access to the particular device, and the system memory controller will act as arbitrator to grant or not grant access to the particular memory card or device requesting access. If access is granted the bus memory controller outputs the required control or command word on the serial bus followed by the address and the required data.

Abstract: A serial bus and connection to a device on a computer system through a system memory controller is provided on a memory card having a DSP and a memory bus controller to allow the DSP on the memory card to gain access to the system device without using the system memory bus. The serial bus is a two wire serial bus connecting the device to the DSP through the system memory controller. If more than one memory card is present with DSPs or more than one device is contending for access, the system memory controller or arbitrate the access of each memory card or contending device. In such case the serial bus will signal the system memory controller when it wants access to the particular device, and the system memory controller will act as arbitrator to grant or not grant access to the particular memory card or device requesting access. If access is granted the bus memory controller outputs the required control or command word on the serial bus followed by the address and the required data.

Abstract: A memory module for attachment to a computer system having a memory bus and a method of using the memory module for error correction by scrubbing soft errors on-board the module is provided. The module includes a printed circuit card with memory storage chips on the card to store data bits and associated ECC check bits. Tabs are provided on the circuit card to couple the card to the memory bus of the computer system. Logic circuitry selectively operatively connects and disconnects the memory chip and the memory bus. A signal processor is connected in circuit relationship with the memory chips.

Abstract: The disclosed invention relates generally to electronic data storage systems that access data storage memory modules via a data bus comprised of multiple data query lines and, more particularly, to an electronic data storage system provided with a data bus that can be selectively provided with terminations thereby permitting the data storage memory to use either modules that require that the data query lines be open-ended, i.e., without terminations or modules that require that the data bus be terminated and to a method for operating such a system. The present invention is particularly directed to a single memory system that can accommodate either 3.3V DIMMs or DDR DIMMs. This is especially accomplished by providing the processor circuit, used in memory storage systems, with both (3.

Abstract: An improved memory module and its use in a computer system is provided. The module includes a DSP first and second individually addressable banks of memory chips. The first bank is configured to function principally under the control of the signal processing element and the second bank is configured to function principally under the control of a system memory controller, although all the portions of each of the memory banks is addressable by both the signal processing element and the system memory controller. Both banks of memory chips can be placed in at least one higher power state and at least one lower power state by either the system memory controller or the DSP. The activity of each bank is sensed while in the higher power state, and the condition of each of the banks is sensed with respect to any activity during operation of the memory bank at the higher power state.