Abstract: A memory system that has a multi-channel volatile memory subsystem is coupled to a non-volatile memory subsystem to provide independent, configurable backup of data. The volatile memory subsystem has one or more main memory modules that use a form of volatile memory such as DRAM memory, for which the NV subsystem provides selective persistent backup. The main memory modules are dual in-line memory modules or DIMMs using DDR SDRAM memory devices. The non-volatile memory subsystem (NV backup) includes an NV controller and non-volatile memory NVM. The NV backup can also include a memory cache to aid with handling and storage of data. In certain embodiments, the NV controller and the nonvolatile memory are coupled to the one or more DIMM channels of the main memory via associated signal lines. Such signal lines can be, for example, traces on a motherboard, and may include one or more signal buses for conveying data, address, and/or control signals.

Abstract: A memory module operable to communicate data with a memory controller via a memory bus. The memory module comprises memory devices and logic configurable to receive and register a set of input address and control signals associated with a read or write memory command and to output data transfer control signals. The memory module further comprises circuitry coupled between the memory bus and the memory devices. The circuitry is configurable to be in any of a plurality of states including a first state and a second state, and to transition from the first state to the second state in response to the data transfer control signals. The circuitry in the first state is configured to disable signal communication through the circuitry. The circuitry in the second state is configured to transfer the data signals associated with the read or write command in accordance with a transfer time budget of the memory module.

Abstract: A system can include a host computer system and a host system bus coupled to the host computer system. One or more storage devices can be coupled to the host system bus and configured to store data. Additionally, a computational storage device (CSD) can be coupled to the host system bus and configured to receive a data write request comprising data from the host computer system. The CSD can further include a memory and an application processor. The application processor of the CSD can be configured to write the data of the data write request to the one or more storage devices in response to receiving the data write request.

Abstract: A system and method for configuring fault tolerance in nonvolatile memory (NVM) are operative to set a first threshold value, declare one or more portions of NVM invalid based on an error criterion, track the number of declared invalid NVM portions, determine if the tracked number exceeds the first threshold value, and if the tracked number exceeds the first threshold value, perform one or more remediation actions, such as issue a warning or prevent backup of volatile memory data in a hybrid memory system. In the event of backup failure, an extent of the backup can still be assessed by determining the amount of erased NVM that has remained erased after the backup, or by comparing a predicted backup end point with an actual endpoint.

Abstract: A memory module is operable in a computer system having a memory controller and a system bus and comprises memory devices organized in one or more ranks and in a plurality of groups, and circuits configurable to receive from the memory controller a system clock and input control and address (C/A) signals, and output registered C/A signals and buffer control signals. The memory module further comprises a plurality of buffer circuits. In response to the buffer control signals, each buffer circuit is configured to communicate first data/strobe signals with at least one memory device and to communicate second data/strobe signals with the memory controller. The buffer circuit includes at least one delay circuit configured to delay at least one signal of the first data/strobe signals based on a first delay and a second delay.

Abstract: A memory expansion device operable with a host computer system (host) comprises a non-volatile memory (NVM) subsystem, cache memory, and control logic configurable to receive a submission from the host including a read command and specifying a payload in the NVM subsystem and demand data in the payload. The control logic is configured to request ownership of a set of cache lines corresponding to the payload, to indicate completion of the submission after acquiring ownership of the cache lines, and to load the payload to the cache memory. The set of cache lines correspond to a set of cache lines in a coherent destination memory space accessible by the host. The control logic is further configured to, after indicating completion of the submission and in response to a request from the host to read demand data in the payload, return the demand data after determining that the demand data is in the cache memory.

Abstract: A memory subsystem is operable with a memory controller of a host computer system via an interface. The memory subsystem comprises dynamic random access memory elements and a memory subsystem controller. The memory subsystem controller has an open drain output, and is configured to provide a first signaling interface via the open drain output during normal operations and a second signaling interface via the open drain output during an initialization operation. The second signaling interface is distinct from the first signaling interface and the initialization operation is distinct from any of the normal operations. The first signaling interface is used by the memory subsystem controller to indicate a parity error in response to a parity error having occurred during the normal operations. The second signaling interface is used by the memory subsystem controller to output a signal related to initialization operation sequences during the initialization operation.

Abstract: A memory module according to some embodiments is operable in a computer system including a memory controller coupled to a memory channel. The memory module comprises a volatile memory subsystem, non-volatile (NV) memory subsystem and a module controller coupled to the volatile memory subsystem and the NV memory subsystem. The volatile memory subsystem includes dynamic random access memory (DRAM) devices and is configurable to communicate with the memory controller via the memory channel during memory read or write operations. The module controller is configured to output data strobe signals to accompany data from the volatile memory subsystem during a memory read operation and to output to accompany data strobes output by data buffers in response to data strobe signals from the memory controller during a system-initiated operation to transfer data from the NV memory subsystem to the volatile memory subsystem.

Abstract: A memory module comprises dynamic random access memory (DRAM) devices arranged in ranks, and a module controller configurable to receive address and control signals for a memory operation, and to output first module control signals to the DRAM devices, causing a selected rank to output or receive N-bit-wide data. The module controller is further configurable to output second module control signals to a plurality of data buffers coupled to the DRAM devices via module data lines. Each respective data buffer includes a n-bit-wide (n<N) data path and logic configurable to, in response to the second module control signals, enable the n-bit-wide data path to receive and regenerate signals carrying a respective n-bit-wide section of the N-bit-wide data communicated from/to a respective n-bit-wide section of the module data lines. The logic is further configurable to disable the n-bit-wide data path when the memory module is not being accessed for data.

Abstract: A system and method for configuring fault tolerance in nonvolatile memory (NVM) are operative to set a first threshold value, declare one or more portions of NVM invalid based on an error criterion, track the number of declared invalid NVM portions, determine if the tracked number exceeds the first threshold value, and if the tracked number exceeds the first threshold value, perform one or more remediation actions, such as issue a warning or prevent backup of volatile memory data in a hybrid memory system. In the event of backup failure, an extent of the backup can still be assessed by determining the amount of erased NVM that has remained erased after the backup, or by comparing a predicted backup end point with an actual endpoint.

Abstract: According to certain aspects, a memory subsystem is coupled to a memory controller of a host computer system via an interface. The memory subsystem comprises dynamic random access memory elements and a memory subsystem controller. During a normal memory read or write operation, the memory subsystem controller is configured to receive address and command signals associated with the memory read or write operations and to control the dynamic random access memory elements in accordance with the address and command signals. The memory subsystem controller is further configured to output via the open drain output a parity error signal in response to a parity error having occurred during the memory read or write operation. During an initialization operation, the memory subsystem controller is configured to output via the open train output a signal related to one or more parts of initialization operation sequences.

Abstract: A memory system that has a multi-channel volatile memory subsystem is coupled to a non-volatile memory subsystem to provide independent, configurable backup of data. The volatile memory subsystem has one or more main memory modules that use a form of volatile memory such as DRAM memory, for which the NV subsystem provides selective persistent backup. The main memory modules are dual in-line memory modules or DIMMs using DDR SDRAM memory devices. The non-volatile memory subsystem (NV backup) includes an NV controller and non-volatile memory NVM. The NV backup can also include a memory cache to aid with handling and storage of data. In certain embodiments, the NV controller and the nonvolatile memory are coupled to the one or more DIMM channels of the main memory via associated signal lines. Such signal lines can be, for example, traces on a motherboard, and may include one or more signal buses for conveying data, address, and/or control signals.

Abstract: A memory module is operable in a computer system to communicate data with a system memory controller via a system memory bus. The memory module comprises a plurality of memory devices mounted on a circuit board, a data module mounted on the circuit board and coupled between the plurality of memory devices and the system memory bus, and a control circuit mounted on the circuit board and coupled to the data module, the plurality of memory devices, and the system memory bus. The data module includes a plurality of data handlers in a plurality of integrated circuits. The memory module is operable in any of a plurality of modes, including a first mode and a second mode. The plurality of memory devices in the first mode is accessed by the system memory controller for normal memory read or write operations.

Abstract: A system and method for configuring fault tolerance in nonvolatile memory (NVM) are operative to set a first threshold value, declare one or more portions of NVM invalid based on an error criterion, track the number of declared invalid NVM portions, determine if the tracked number exceeds the first threshold value, and if the tracked number exceeds the first threshold value, perform one or more remediation actions, such as issue a warning or prevent backup of volatile memory data in a hybrid memory system. In the event of backup failure, an extent of the backup can still be assessed by determining the amount of erased NVM that has remained erased after the backup, or by comparing a predicted backup end point with an actual endpoint.

Abstract: The present application presents a Uniform Memory Access (UMA) network including a cluster of UMA nodes. A system in a UMA node comprises persistent memory; non-persistent memory, a node control device operatively coupled to the persistent memory and the non-persistent memory, a local interface for interfacing with the local server in the respective UMA node, and a network interface for interfacing with the UMA network. The node control device is configured to translate between a local unified memory access (UMA) address space accessible by applications running on a local server and a global UMA address space that is mapped to a physical UMA address space. The physical UMA address space includes physical address spaces associated with different UMA nodes in the cluster of UMA nodes. Thus, a server in the UMA network can access the physical address spaces at other UMA nodes without going through the servers in the other UMA nodes.

Abstract: A memory module is operable in a memory system with a memory controller. The memory module comprises memory devices, a module control circuit, and a plurality of buffer circuits coupled between respective sets of data signal lines in a data bus and respective sets of the memory devices. Each respective buffer circuit is mounted on the module board and coupled between a respective set of data signal lines and a respective set of memory devices. Each respective buffer circuit is configured to receive the module control signals and the module clock signal, and to buffer a respective set of data signals in response to the module control signals and the module clock signal. Each respective buffer circuit includes a delay circuit configured to delay the respective set of data signals by an amount determined based on at least one of the module control signals.

Abstract: A memory module comprises a volatile memory subsystem including DRAM, a non-volatile memory subsystem including Flash memory, and a module control device. The Flash memory includes main Flash providing a main Flash memory space and scratch Flash providing a scratch Flash memory space. The module control device is configured to receive a request from the memory controller to move one or more segments of data in a first Flash block in the main Flash to the DRAM and to, for each respective segment of data: select a respective set of pages in the DRAM; transfer respective data stored in the respective set of pages from the DRAM to a corresponding segment in the scratch Flash; and transfer the respective segment of data to the respective set of pages in the DRAM. Thus, data can be moved segment by segment between the DRAM and the Flash memory.

Abstract: A memory module comprises a volatile memory subsystem, a non-volatile memory subsystem, and a module controller coupled to the volatile memory subsystem and to the non-volatile memory subsystem. The module controller is configurable to control data transfers between the volatile memory subsystem and the non-volatile memory subsystem. The module controller includes a data selection circuit configurable to pre-search data transferred from the non-volatile memory with respect to one or more search criteria before providing the pre-select data relevant to the one or more search criteria to the volatile memory subsystem.

Abstract: A memory system that has a multi-channel volatile memory subsystem is coupled to a non-volatile memory subsystem to provide independent, configurable backup of data. The volatile memory subsystem has one or more main memory modules that use a form of volatile memory such as DRAM memory, for which the NV subsystem provides selective persistent backup. The main memory modules are dual in-line memory modules or DIMMs using DDR SDRAM memory devices. The non-volatile memory subsystem (NV backup) includes an NV controller and non-volatile memory NVM. The NV backup can also include a memory cache to aid with handling and storage of data. In certain embodiments, the NV controller and the non-volatile memory are coupled to the one or more DIMM channels of the main memory via associated signal lines. Such signal lines can be, for example, traces on a motherboard, and may include one or more signal buses for conveying data, address, and/or control signals.

Abstract: A memory module is operable in a memory system with a memory controller. The memory module comprises a module control device to receive command signals and a system clock from the memory controller and to output a module clock, module C/A signals and data buffer control signals. The module C/A signals are provided to memory devices organized in one or more ranks, while the data buffer control signals, together with the module clock, are provided to a plurality of buffer circuits corresponding to respective groups of memory devices and are used to control data paths in the buffer circuits. The plurality of buffer circuits include clock regeneration circuits to regenerate clock signals with programmable delays from the module clock. The regenerated clock signals are provided to respective groups of memory devices so as to locally sync the buffer circuits with respective groups of memory devices.