Abstract: A high reliability dual inline memory module with a fault tolerant address and command bus for use in a server. The memory module is a card approximately 151.35 mm or 5.97 inches long provided with about a plurality of contacts of which some are redundant, a plurality of DRAMs, a phase lock loop, a 2 or 32 K bit serial EE PROM and a 28 bit and a 1 to 2 register having error correction code (ECC), parity checking, a multi-byte fault reporting circuitry for reading via an independent bus, and real time error lines for determining and reporting both correctable errors and uncorrectable error conditions coupled to the server's memory interface chip and memory controller or processor such that the memory controller sends address and command information to the register via address/command lines together with check bits for error correction purposes to the ECC/Parity register.

Abstract: A memory hub device with test logic is configured to communicate with memory devices via multiple hub device ports, and is also configured to communicate on one or more busses in an upstream and downstream direction. The test logic includes a built-in self test apparatus providing logic to simultaneously and independently test the memory devices interfaced to one or more of the hub device ports using read and write data patterns. The test logic also includes configuration registers to hold fault and diagnostic information, and to initiate one or more tests. The memory hub device can further include command collision detection logic, a trace array, buffer transmit mode logic, trigger logic, clock adjustment logic, transparent mode logic, and a configured command sequencer, as well as additional features.

Abstract: A memory system includes a memory controller, one or more memory channel(s), and a memory subsystem having a memory interface device (e.g. a hub or buffer device) located on a memory subsystem (e.g. a DIMM) coupled to the memory channel to communicate with the memory device(s) array. This buffered DIMM is provided with one or more spare chips on the DIMM, wherein the data bits sourced from the spare chips are connected to the memory hub device and the bus to the DIMM includes only those data bits used for normal operation. The buffered DIMM with one or more spare chips on the DIMM has the spare memory shared among all the ranks, and the memory hub device includes separate control bus(es) for the spare memory device to allow the spare memory device(s) to be utilized to replace one or more failing bits and/or devices within any rank of memory in the memory subsystem.

Abstract: A computer memory, having one or more of a semiconductor memory device having an internal memory array comprising a plurality of semiconductor dynamic random access memory (DRAM) cells arranged in a matrix of rows and columns, and provided as a memory module rank of such memory devices arranged in an array on a DIMM of one or more of said semiconductor memory device on a substrate which can be coupled via a memory device data interface to a memory system as a memory subsystem, each of said memory device having a low power shut-down state that can be activated using a common memory data interface. Control of power to a DRAM issues over the data interface two commands to a DRAM power control command decode, a power-state program signal and a power-state reset signal as a power-state control commands to control the power state of said DRAM, and to activate for READ/WRITE a memory cell as a normal active or spare device.

Abstract: Testing a model of a logic circuit model. The testing includes generating valid random input stimulus sequences for a logic circuit model. Enumerating critical resource requirements, enumerating critical resource availabilities does this, and selecting of stimulus sequences and determining legal times for execution of said stimulus sequences based on resource availability. This includes generating a plurality of possible combinations of input stimulus sequences and generating an array representation of critical resource requirements. These are used to generate an array representation of critical resources availabilities.

Abstract: A dual inline memory module (DIMM) includes a card having a length of about 151.2 to about 151.5 millimeters, a plurality of individual local memory devices attached to the card, and a buffer device attached to the card, the buffer device configured for converting a packetized memory interface. The card includes at least 276 pins configured thereon.

Abstract: A memory subsystem system including a rectangular printed circuit card having a first side and a second side, a length of between 149.5 and 153.5 millimeters, and first and second ends having a width smaller than the length. The memory system also includes a first plurality of pins on the first side extending along a first edge of the card that extends the length of the card, and a second plurality of pins on the second side extending on the first edge of the card. The memory system further includes a positioning key having it center positioned on the first edge of the card and located between 84.5 and 88.5 millimeters from the first end of the card and located between 62.5 and 66.5 millimeters from the second end of the card.

Abstract: A method for providing indeterminate read data latency in a memory system. The method includes determining if a local data packet has been received and storing it into a buffer device. The method also includes determining if the buffer device contains a data packet and determining if an upstream driver for transmitting data packets to a memory controller via an upstream channel is idle, and in response thereto the data packet is transmitted to the upstream driver. The method further includes determining if an upstream data packet has been received and the upstream driver is not idle, then the upstream data packet is stored into the buffer device. The upstream data packet is selectively transmitted to the upstream driver. If the upstream driver is not idle, then any data packets in progress are continued being transmitted to the upstream driver.

Abstract: Systems and methods for providing collision detection in a memory system including a memory system for storing and retrieving data for a processing system. The memory system includes resource scheduling conflict logic for monitoring one or more memory resources for detecting resource scheduling conflicts. The memory system also includes error reporting logic for generating an error signal in response to detecting a resource scheduling conflict at one or more of the memory resources.

Abstract: A communication interface device, system, method, and design structure for error correcting code (ECC) protected quasi-static bit communication (SBC) on a high-speed bus are provided. The communication interface device includes high-speed sampling logic to capture high-speed data from the high-speed bus using a high-speed sampling clock and SBC sampling logic to capture SBC samples from the high-speed bus using an SBC sampling clock. The SBC sampling clock is slower than the high-speed sampling clock. The communication interface device also includes an SBC finite state machine (FSM) to detect a received SBC command in response to a static pattern persisting for a predetermined number of the SBC samples and command decoding logic to decode the received SBC command.

Abstract: A hub device, memory system, and method for providing a cascade interconnect memory system with enhanced reliability. The hub device includes an interface to a high-speed bus for communicating with a memory controller. The memory controller and the hub device are included in a cascade interconnect memory system and the high-speed bus includes bit lanes and one or more clock lanes. The hub device also includes a bi-directional fault signal line in communication with the memory controller and readable by a service interface. The hub device also includes a fault isolation register (FIR) for storing information about failures detected at the hub device, the information including severity levels of the detected failures. In addition, the hub device includes error recovery logic for responding to a failure detected at the hub device. Responding to the error includes recording a severity level of the failure in the FIR and taking an action at the hub device that is responsive to the severity level of the failure.

Abstract: A memory module that includes a first group of memory devices arranged in one or more ranks and a second group of memory devices arranged in one or more ranks. The memory module also includes a first and second port, wherein the first port is operable simultaneously with and independently of the second port. The memory module further includes a first memory device bus in communication with the first port and the first group of memory devices, and a second memory device bus in communication with the second port and the second group of memory devices. The memory module further includes a hub device configured to re-drive information in a cascade interconnect system. The hub device includes logic for reading data from and writing data to the ranks of memory devices via the first and second ports and the first and second memory device buses.

Abstract: A system and method for providing a cyclical redundancy code (CRC) for use in a high-speed serial link. The system includes a cascade interconnect memory system including a memory controller, a memory hub device and a downstream link. The downstream link is in communication with the memory controller and the memory hub device and includes at least thirteen signal lanes for transmitting a multiple transfer downstream frame from the memory controller to the memory hub device. A portion of the downstream frame includes downstream CRC bits to detect errors in the downstream frame. The downstream CRC bits capable of detecting any one of a lane failure, a transfer failure and up to five bit random errors.

Abstract: A communication interface device, system, method, and design structure for enhancing bus efficiency and utilization in a memory system. The communication interface device includes a first bus interface to communicate on a high-speed bus, a second bus interface to communicate on a lower-speed bus, and clock ratio logic configurable to support multiple clock ratios between the high-speed bus and the lower-speed bus. The clock ratio logic reduces a high-speed clock frequency received at the first bus interface and outputs a reduced ratio of the high-speed clock frequency on the lower-speed bus via the second bus interface supporting variable frame sizes.

Abstract: A processing device, system, method, and design structure for providing a microprocessor interface with dynamic segment sparing and repair. The processing device includes drive-side switching logic including driver multiplexers to select driver data for transmitting on link segments of a bus, and receive-side switching logic including receiver multiplexers to select received data from the link segments of the bus. The bus includes multiple data link segments, a clock link segment, and at least two spare link segments selectable by the drive-side switching logic and the receive-side switching logic to replace one or more of the data link segments and the clock link segment.

Abstract: Systems and methods for providing a variable frame format protocol in a cascade interconnected memory system. The systems include a memory hub device that utilizes a first bus interface to communicate on a high-speed bus. The hub device also includes frame decode logic for translating variable format frames received via the first bus interface into memory device commands and data. The translating includes identifying write data headers and associated write data for self-registering write to data buffer commands.

Abstract: A communication interface device, system, method, and design structure for providing dynamic segment sparing and repair in a memory system. The communication interface device includes drive-side switching logic including driver multiplexers to select driver data for transmitting on link segments of a bus, and receive-side switching logic including receiver multiplexers to select received data from the link segments of the bus. The bus includes multiple data link segments, a clock link segment, and at least two spare link segments selectable by the drive-side switching logic and the receive-side switching logic to replace one or more of the data link segments and the clock link segment.

Abstract: A system, memory hub device, method and design structure for providing an enhanced cascade interconnected memory system are provided. The system includes a memory controller, a memory channel, a memory hub device coupled to the memory channel to communicate with the memory controller via one of a direct connection and a cascade interconnection through another memory hub device, and multiple memory devices in communication with the memory controller via one or more cascade interconnected memory hub devices. The memory channel includes unidirectional downstream link segments coupled to the memory controller and operable for transferring configurable data frames. The memory channel further includes unidirectional upstream link segments coupled to the memory controller and operable for transferring data frames.

Abstract: A memory subsystem system including a rectangular printed circuit card having a first side and a second side, a length of between 149.5 and 153.5 millimeters, and first and second ends having a width smaller than the length. The memory system also includes a first plurality of pins on the first side extending along a first edge of the card that extends the length of the card, and a second plurality of pins on the second side extending on the first edge of the card. The memory system further includes a positioning key having it center positioned on the first edge of the card and located between 84.5 and 88.5 millimeters from the first end of the card and located between 62.5 and 66.5 millimeters from the second end of the card.

Abstract: A processing device, processing system, method, and design structure for an enhanced microprocessor interconnect with bit shadowing are provided. The processing device includes shadow selection logic to select a driver bit position as a shadowed driver value, and line drivers to transmit data for the selected driver bit position and the shadowed driver value on separate link segments of a bus. The processing device also includes shadow compare logic to compare a selected received value with a shadowed received value from the bus and identify a miscompare in response to a mismatch of the compare, and shadow counters to count a rate of the miscompare relative to a bus error rate over a period of time. A defective link segment is identified in response to the rate of the miscompare within a predefined threshold of the bus error rate.