Abstract:
A dual function memory device architecture compatible with asynchronous operation and synchronous serial operation. The dual function memory device architecture includes one set of physical ports having two different functional assignments. Coupled between the physical ports and core circuits of the memory device are asynchronous and synchronous input and output signal paths or circuits. The signal paths include shared or dedicated buffers coupled to the ports, asynchronous and synchronous command decoders, a network of switches, and a mode detector. The mode detector determines the operating mode of the dual function memory device from a port, and provides the appropriate switch selection signal. The network of switches routes the input or output signals through the asynchronous or synchronous circuits in response to the switch selection signal. The appropriate command decoder interprets the input signals and provides common control logic with the necessary signals for initiating the corresponding operation.
Abstract:
Apparatus and methods for carrying out operations in a non-volatile memory cell having multiple memory states are disclosed. One of the methods is a method for programming N bits in a non-volatile memory cell configured to store up to N+1 bits, where N is an integer greater than zero. The method for programming includes programming N bits of data in the cell. The method for programming also includes programming an additional bit of data that is a logical function of the N bits of data in the cell. The cell is configured to provide 2N+1 threshold voltage ranges for bit storage and, in accordance with the logical function: i) a first set of 2N threshold voltage ranges of the 2N+1 threshold voltage ranges are used to store the N bits of data; and ii) a remaining second set of 2N threshold voltage ranges alternating with the first set are unused.
Abstract:
A semiconductor device includes a bridging device having an external data interface, an external status interface, and a plurality of internal data interfaces. A plurality of memory devices are each connected to the bridging device via one of the internal data interfaces. Each of the memory devices has a ready/busy output connected to an input of the bridging device. The bridging device is configured to output a current state of each ready/busy output in a packetized format on the external status interface in response to a status request command received on the external status interface; and read information from a status register of a selected memory device over one of the internal data interfaces and provide the information on the external data interface in response to a status read command received on the external data interface. A method of operating a semiconductor device is also disclosed.
Abstract:
A delay locked loop operates over a wide range of frequencies and has high accuracy, small silicon area usage, low power consumption and a short lock time. The DLL combines an analog domain and a digital domain. The digital domain is responsible for initial lock and operational point stability and is frozen after the lock is reached. The analog domain is responsible for normal operation after lock is reached and provides high accuracy using smaller silicon area and low power.
Abstract:
A composite memory device including discrete memory devices and a bridge device for controlling the discrete memory devices. A configurable clock controller receives a system clock and generates a memory clock having a frequency that is a predetermined ratio of the system clock. The system clock frequency is dynamically variable between a maximum and a minimum value, and the ratio of the memory clock frequency relative to the system clock frequency is set by loading a frequency register with a Frequency Divide Ratio (FDR) code any time during operation of the composite memory device. In response to the FDR code, the configurable clock controller changes the memory clock frequency.
Abstract:
The present invention includes a circuit, system and method for selectively turning off internal clock drivers to reduce operating current. The present invention may be used to reduce power consumption by reducing operating current in a memory device. Operating current may be reduced by turning off internal clock drivers that deliver a clock signal during selected periods of time. According to an embodiment of clock control circuitry of the present invention, an internal clock is disabled if a no operation command is detected during periods of time when no read or write burst operation is taking place. Methods, memory devices and computer systems including the clock control circuitry and its functionality are also disclosed.
Abstract:
A memory device of the non-volatile type including a memory array having a plurality of memory cells organized as sectors, each sector having a main word line associated with a plurality of local word lines, each local word line coupled to the main word line by a respective local word line driver circuit, each of the local word line driver circuits consisting of a first MOS transistor coupled between the respective main word line and a respective local word line and a second MOS transistor coupled between the respective local word line and a first biasing terminal.
Abstract:
A system includes a memory controller and a plurality of memory devices that are connected in-series to the memory controller. The system operation is synchronous with clock that is provided in a fashion of source synchronous clock structure. The source synchronous clock structure includes a PLL (Phase-Locked Loop) that reshapes an incoming clock and a reshaped clock is provided. The PLL provides a shifted clock in phase of 90°. The phase-shifted clock and data are transmitted from the first device to the second device. Clock phase shift provides a center-edge clock with data to be transmitted. The devices are assigned with unique IDs. The least significant bit of the ID number of the last device is used for determination of clock alignment: edge- or center-aligned clock with data produced by the memory controller.
Abstract:
A clock mode configuration circuit for a memory device is described. A memory system includes any number of memory devices serially connected to each other, where each memory device receives a clock signal. The clock signal can be provided either in parallel to all the memory devices or serially from memory device to memory device through a common clock input. The clock mode configuration circuit in each memory device is set to a parallel mode for receiving the parallel clock signal, and to a serial mode for receiving a source synchronous clock signal from a prior memory device. Depending on the set operating mode, the data input circuits will be configured for the corresponding data signal format, and the corresponding clock input circuits will be either enabled or disabled. The parallel mode and the serial mode is set by sensing a voltage level of a reference voltage provided to each memory device.
Abstract:
A memory system architecture has serially connected memory devices. The memory system is scalable to include any number of memory devices without any performance degradation or complex redesign. Each memory device has a serial input/output interface for communicating between other memory devices and a memory controller. The memory controller issues commands in at least one bitstream, where the bitstream follows a modular command protocol. The command includes an operation code with optional address information and a device address, so that only the addressed memory device acts upon the command. Separate data output strobe and command input strobe signals are provided in parallel with each output data stream and input command data stream, respectively, for identifying the type of data and the length of the data. The modular command protocol is used for executing concurrent operations in each memory device to further improve performance.