Abstract: One or more multi-level NAND flash cells are operated so as to store only single-level data, and these operations achieve an increased level of charge separation between the data states of the single-level operation by requiring a write to both the upper and lower pages, even though only one bit of data is being stored. That is, the second write operation increases the difference in floating gate charge between the erased state and the programmed state of the first write operation without changing the data in the flash memory cell. In one embodiment, a controller instructs the flash memory to perform two write operations for storing a single bit of data in an MLC flash cell. In another embodiment, the flash memory recognizes that a single write operation is directed a high reliability memory area and internally generates the required plurality of programming steps to place at least a predetermined amount of charge on the specified floating gate.

Abstract: Memory modules address the growing gap between main memory performance and disk drive performance in computational apparatus such as personal computers. Memory modules disclosed herein fill the need for substantially higher storage capacity in end-user add-in memory modules. Such memory modules accelerate the availability of applications, and data for those applications. An exemplary application of such memory modules is as a high capacity consumer memory product that can be used in Hi-Definition video recorders. In various embodiments, memory modules include a volatile memory, a non-volatile memory, and a command interpreter that includes interfaces to the memories and to various busses. The first memory acts as an accelerating buffer for the second memory, and the second memory provides non-volatile backup for the first memory. In some embodiments data transfer from the first memory to the second memory may be interrupted to provide read access to the second memory.

Abstract: Memory modules address the growing gap between main memory performance and disk drive performance in computational apparatus such as personal computers. Memory modules disclosed herein fill the need for substantially higher storage capacity in end-user add-in memory modules. Such memory modules accelerate the availability of applications, and data for those applications. An exemplary application of such memory modules is as a high capacity consumer memory product that can be used in Hi-Definition video recorders. In various embodiments, memory modules include a volatile memory, a non-volatile memory, and a command interpreter that includes interfaces to the memories and to various busses. The first memory acts as an accelerating buffer for the second memory, and the second memory provides non-volatile backup for the first memory. In some embodiments data transfer from the first memory to the second memory may be interrupted to provide read access to the second memory.

Abstract: One or more multi-level NAND flash cells are operated so as to store only single-level data, and these operations achieve an increased level of charge separation between the data states of the single-level operation by requiring a write to both the upper and lower pages, even though only one bit of data is being stored. That is, the second write operation increases the difference in floating gate charge between the erased state and the programmed state of the first write operation without changing the data in the flash memory cell. In one embodiment, a controller instructs the flash memory to perform two write operations for storing a single bit of data in an MLC flash cell. In another embodiment, the flash memory recognizes that a single write operation is directed a high reliability memory area and internally generates the required plurality of programming steps to place at least a predetermined amount of charge on the specified floating gate.

Abstract: Providing electrical isolation between the chipset and the memory data is disclosed. The disclosure includes providing at least one buffer in a memory interface between a chipset and memory modules. Each memory module includes a plurality of memory ranks. The buffers allow the memory interface to be split into first and second sub-interfaces. The first sub-interface is between the chipset and the buffers. The second sub-interface is between the buffers and the memory modules. The method also includes interleaving output of the buffers, and configuring the buffers to properly latch the data being transferred between the chipset and the memory modules. The first and second sub-interfaces operate independently but in synchronization with each other.

Abstract: Methods and apparatus for a memory system using a new memory module architecture are disclosed. In one embodiment, the memory module has two ranks of memory devices, each rank connected to a corresponding one of two 64-bit-wide data registers. The data registers connect to two 64-bit-wide ports of a 128:64 multiplexer/demultiplexer, and a 64-bit-wide data buffer connects to the opposite port of the multiplexer/demultiplexer. A controller synchronizes the operation of the data registers, the multiplexer/demultiplexer, and the data buffer. In an operating environment, the data buffer connects to a memory bus. When a data access is performed, both ranks exchange data signaling with their corresponding data registers during a single data access. At the buffer, the memory bus data transfer occurs in two consecutive clock cycles, one cycle for each rank. This allows the memory bus transfer rate to double for the same memory bus width and memory device speed.

Abstract: A memory component with built-in self test includes a memory array. An input/output interface is coupled to the memory array and has a loopback. A controller is provided to transmit memory array test data to the memory array to store the memory array test data, and to read the memory array test data from the memory array. A compare register is also provided to compare the memory array test data transmitted to the memory array with the memory array test data read from the memory array.

Abstract: Technique and system for adjusting delays between signals. A number of signals are produced, and delays between the signals are determined. Programmable delay elements are used, each driven by a signal indicative of one of the delays. By delaying each of a number of the signals by different amounts, the signals can be caused to arrive at desired times, e.g., in synchronism with one another.

Abstract: Buffering data transfer between a chipset and memory modules is disclosed. The disclosure includes providing and configuring at least one buffer. The buffers are provided in an interface between a chipset and memory modules. The buffers allow the interface to be split into first and second sub-interfaces. The first sub-interface is between the chipset and the at least one buffer. The second sub-interface is between the at least one buffer and the memory modules. The buffers are then configured to properly latch the data being transferred between the chipset and the memory modules. The first and second sub-interfaces operate independently but in synchronization with each other.

Abstract: Providing electrical isolation between the chipset and the memory data is disclosed. The disclosure includes providing at least one buffer in a memory interface between a chipset and memory modules. Each memory module includes a plurality of memory ranks. The buffers allow the memory interface to be split into first and second sub-interfaces. The first sub-interface is between the chipset and the buffers. The second sub-interface is between the buffers and the memory modules. The method also includes interleaving output of the buffers, and configuring the buffers to properly latch the data being transferred between the chipset and the memory modules. The first and second sub-interfaces operate independently but in synchronization with each other.

Abstract: The present invention utilizes a buffer to isolate a stack of memory devices, thereby taking advantage of the increased memory density available from stacked memory devices while reducing capacitive loading. A memory module in accordance with the present invention may include a stack of memory devices and a buffer coupled to the first and second memory devices and arranged to capacitively isolate the first and second memory devices from a bus. In a memory system in accordance with the present invention, multiple buffered stacks of memory devices are preferably coupled in a point-to-point arrangement, thereby further reducing capacitive loading.

Abstract: Methods and apparatus for a memory system using a new memory module architecture are disclosed. In one embodiment, the memory module has two ranks of memory devices, each rank connected to a corresponding one of two 64-bit-wide data registers. The data registers connect to two 64-bit-wide ports of a 120:64 multiplexer/demultiplexer, and a 64-bit-wide data buffer connects to the opposite port of the multiplexer/demultiplexer. A controller synchronizes the operation of the data registers, the multiplexer/demultiplexer, and the data buffer. In an operating environment, the data buffer connects to a memory bus. When a data access is performed, both ranks exchange data signaling with their corresponding data registers during a single data access. At the buffer, the memory bus data transfer occurs in two consecutive clock cycles, one cycle for each rank. This allows the memory bus transfer rate to double for the same memory bus width and memory device speed.

Abstract: Providing electrical isolation between the chipset and the memory data is disclosed. The disclosure includes providing at least one buffer in a memory interface between a chipset and memory modules. Each memory module includes a plurality of memory ranks. The buffers allow the memory interface to be split into first and second sub-interfaces. The first sub-interface is between the chipset and the buffers. The second sub-interface is between the buffers and the memory modules. The method also includes interleaving output of the buffers, and configuring the buffers to properly latch the data being transferred between the chipset and the memory modules. The first and second sub-interfaces operate independently but in synchronization with each other.

Abstract: Methods and apparatus for a memory system using a ring memory bus architecture are disclosed. In one embodiment, a primary memory controller maintains point-to-point bus connections with each of two memory modules; the two modules maintain a third point-to-point bus connection between themselves, such that the three connections together form a ring bus. When data is sent from the controller to a module, half of the data is sent to the module in one direction along the ring and half is sent in the other direction, through the other module. Reverse bus communications from the module to the controller follow the reverse of these paths. This allows the bus to be half the width as it would otherwise be. In an alternate embodiment, each module contains two banks of memory that are arranged in a second ring bus local to the module. This can double the density of devices mounted on a module, while reducing pin count and simplifying signal routing on the module.

Abstract: A plurality of memory modules interface through a daisy-chain providing a point-to-point connection for each memory module. The first and the last memory module in the daisy chain each connect to a separate memory controller port forming a ring circuit. A distinct set of signals connect the memory modules in each direction. A junction circuit in each memory module provides line isolation, a coupling to the adjoining memory modules in the daisy chain, or in the case of the first and last memory module in the daisy chain, a memory module and a memory controller, and a data synchronization circuit. Each junction circuit provides as well as voltage conversion so that the memory devices on a memory module operate at a different voltage than the memory controller, and multiplexing/de-multiplexing so that a lesser number of lines interface with each junction circuit.

Abstract: Providing electrical isolation between the chipset and the memory data is disclosed. The disclosure includes providing at least one buffer in a memory interface between a chipset and memory modules. Each memory module includes a plurality of memory ranks. The at least one buffer allows the memory interface to be split into first and second sub-interfaces. The first sub-interface is between the chipset and the buffer. The second sub-interface is between the buffer and the memory modules. The method also includes interleaving output of the memory ranks in the memory modules, and configuring the at least one buffer to properly latch data being transferred between the chipset and the memory modules. The first and second sub-interfaces operate independently but in synchronization with each other.

Abstract: The present invention provides a system and method for providing reliable transmission in a buffered memory system. The system includes memory devices, a memory controller, data buffers, an address/command buffer, and a clock circuit. The memory controller sends data, address information, status information and command information, to the memory devices and receives data from the memory devices. The buffers interconnect the memory devices and the memory controller. The clock circuit is embedded in the addr/cmd buffer. The clock circuit takes an input clock and outputs an output clock to the data buffers and/or the memory devices to control clock-skew to the data buffers and/or the memory devices.

Abstract: The present invention utilizes a buffer to isolate a stack of memory devices, thereby taking advantage of the increased memory density available from stacked memory devices while reducing capacitive loading. A memory module in accordance with the present invention may include a stack of memory devices and a buffer coupled to the first and second memory devices and arranged to capacitively isolate the first and second memory devices from a bus. In a memory system in accordance with the present invention, multiple buffered stacks of memory devices are preferably coupled in a point-to-point arrangement, thereby further reducing capacitive loading.

Abstract: Methods and apparatus for a memory system using a branching point-to-point memory bus architecture are disclosed. In one embodiment, a primary memory controller maintains a point-to-point bus connection with one memory module and that memory module maintains a separate point-to-point bus connection with a second module. Data passing between the memory controller and the second memory module passes through a buffer circuit on the first memory module. For data received from the memory controller, the buffer circuit also passes that data up a module bus segment to a first bank of memory devices. That bank of memory devices maintains a second module bus segment with a second bank of memory devices. Data passing between the buffer circuit and the second bank of memory devices passes through a pass-through circuit on the first bank of memory devices. In this manner, a point-to-point memory bus architecture can be maintained even when a memory module contains more than one bank of memory devices.

Abstract: The present invention utilizes a buffer to isolate a stack of memory devices, thereby taking advantage of the increased memory density available from stacked memory devices while reducing capacitive loading. A memory module in accordance with the present invention may include a stack of memory devices and a buffer coupled to the first and second memory devices and arranged to capacitively isolate the first and second memory devices from a bus. In a memory system in accordance with the present invention, multiple buffered stacks of memory devices are preferably coupled in a point-to-point arrangement, thereby further reducing capacitive loading.