Abstract: A method for calibrating a DDR memory controller is described. The method provides an optimum delay for a core clock delay element to produce an optimum capture clock signal. The method issues a sequence of read commands so that a delayed version of a dqs signal toggles continuously. The method delays a core clock signal to sample the delayed dqs signal at different delay increments until a 1 to 0 transition is detected on the delayed dqs signal. This core clock delay is recorded as “A.” The method delays the core clock signal to sample the core clock signal at different delay increments until a 0 to 1 transition is detected on the core clock signal. This core clock delay is recorded as “B.” The optimum delay value is computed from the A and B delay values.

Abstract: A method for accessing a semiconductor device having a memory array, the method includes receiving a mode register command to set a command latency value in a mode register, receiving a chip select signal, activating a command receiver in response to the chip select signal, receiving, with the command receiver, an access command with a first latency from the chip select signal equal to the command latency value, accessing the memory array in response to the access command, and deactivating the command receiver with a second latency from the chip select signal equal to a deactivation latency value.

Abstract: A DLL system in a memory device with wide frequency application includes: a clock receiver that generates a clock for the DLL system; a delay line, coupled to the clock receiver, for receiving the generated clock and delaying the clock according to a received power supply; a power regulator, for generating the power supply to the DLL delay line according to a bias; a control logic, coupled to the clock receiver, for generating a plurality of logic signals respectively corresponding to a plurality of frequency ranges of the clock; and a bias generator, coupled between the control logic and the power regulator, for providing the bias to the power regulator, wherein the value of the bias is according to a logic signal output by the control logic.

Abstract: Methods and systems for detection and correction of timing signal drift in memory systems are provided. A start time and an end time of a first time interval is determined with control circuitry such that a last falling edge in a first of a plurality of data strobe sequences received from the memory occurs outside of the first time interval. A start time and an end time of a close-enable time interval is adjusted based at least in part on determining whether a second of the plurality of data strobe sequences occurs within the first time interval. Sampling of data received from the memory is disabled in response to determining that the last falling edge in the second received data strobe sequence occurs within the close-enable time interval.

Abstract: A memory system includes a plurality of memory devices having data terminals that are commonly connected to a memory controller. Each of the memory devices includes a data output circuit that outputs read data that is read from a memory cell array in response to a read command to the data terminal, and an output-timing adjustment circuit that adjusts an output timing of read data that is output from the data output circuit. The memory controller sets an adjustment amount of adjustment performed by an output-timing adjustment circuit such that delay times from when the read command is issued until when the read data is received match in the memory devices, by issuing a setting command to each of the memory devices.

Abstract: A method for robust preamble location and gate training in a Double Data Rate type Three (DDR3) computing environment. A single algorithm is employed to begin sampling a Data Strobe Signal (DQS) at a maximum delay value designed to fall within the driven region of a DQS. The method then begins sampling the DQS in a sequence of delay values from right to left. Each result of the sampling indicating a high state and a low state are stored as well as the occasions where the DQS transitioned from high to low indicating a rising edge. At a consecutive number of samples returning a low state, the method determines the preamble has been reached and discontinues sampling. The method retains the most recently stored rising edge as the first rising edge and configures the result for gate training.

Abstract: An apparatus includes multiple first memory circuits, in which the multiple first memory circuits are positioned on at least one dual in-line memory module (DIMM). The apparatus includes an interface circuit operable to interface the first memory circuits with a system; present the first memory circuits to the system as one or more simulated second memory circuits; transmit, in response to receiving a first refresh control signal sent from the system to the one or more simulated memory circuits, multiple second refresh control signals to the first memory circuits; and apply a respective delay to each second refresh control signal transmitted to a corresponding first memory circuit. Each simulated second memory circuit has a corresponding second memory capacity that is greater than a first memory capacity of at least one of the first memory circuits.

Abstract: A clock transfer circuit includes a clock transfer unit configured to receive an external clock and transfer the received external clock as one or more internal clocks and a clock control unit configured to control the clock transfer unit to transfer the external clock as a column clock among the internal clocks in response to an active command and block a transfer of the external clock as the column clock in response to a precharge command.

Abstract: A method of operation of a non-volatile dynamic random access memory system including: accessing a dynamic random access memory; managing a delay-locked-loop control in the dynamic random access memory; sourcing timing inputs to the dynamic random access memory by a control logic unit with the delay-locked-loop control disabled including: selecting a back-up interface through a first multiplexer and a second multiplexer, asserting an on-board termination, and accessing data in the dynamic random access memory by the control logic unit at a lower frequency; and enabling a memory control interface by the control logic unit, with the delay-locked-loop control enabled including: selecting a host interface through the first multiplexer, the second multiplexer, or a combination thereof, disabling the on-board termination, and accessing the data in the dynamic random access memory by the memory control interface at a delay-locked-loop frequency.

Abstract: An embodiment of a technique to determine an expected occurrence of a signal is disclosed. The technique includes receiving first and second signals, and storing delay information representing an expected time delay from an occurrence of the first signal to a point in time corresponding approximately to an expected occurrence of the second signal. The technique further includes responding to an occurrence of the first signal by: waiting for a time interval equivalent to the expected time delay, evaluating the second signal at approximately the end of the time interval, and adjusting the stored delay information if the second signal occurred outside a time window associated with the end of the time interval.

Abstract: According to one embodiment, a memory system includes a first semiconductor memory and a controller. The first semiconductor memory receives a first clock, and outputs, in accordance with the first clock, a second clock and a data signal in synchronization with the second clock. The controller includes a detection circuit which detects a shift of a duty ratio of the second clock which is output from the first semiconductor memory. The controller also includes an adjustment circuit which adjusts a duty ratio of the first clock based on the shift detected by the detection circuit.

Abstract: A memory interface circuit includes a gating circuit that starts detection of a logic level of a data strobe signal in accordance with a data read command. A clamp circuit clamps the data strobe signal to a first logic level after the data read command is issued. A detection circuit detects a logic level of the data strobe signal, which is driven by the memory, in accordance with the data read command.

Abstract: Multi-rank memories and methods for self-refreshing multi-rank memories are disclosed. One such multi-rank memory includes a plurality of ranks of memory and self-refresh logic coupled to the plurality of ranks of memory. The self-refresh logic is configured to refresh a first rank of memory in a self-refresh state in response to refreshing a second rank of memory not in a self-refresh state in response to receiving a non-self-refresh refresh command for the second rank of memory.

Abstract: A method can include storing bank addresses, if received, on at least rising and falling edges of a same clock cycle; and if addresses stored on the rising and falling edges of the same clock cycle correspond to different banks of a memory device, starting accesses to both banks after the falling edge of the clock cycle; wherein any of the banks can be accessed in response to an address stored on a rising edge of a next clock cycle. Devices and additional methods are also disclosed.

Abstract: A double data rate pseudo SRAM (DDR PSRAM) is provided. The DDR PSRAM includes a data receiver, a memory and an address decoder. The data receiver receives a first single data rate data from a controller via a common bus according to a clock. The address decoder decodes the first single data rate data to obtain an address of the memory. The data receiver stores the double data rate data into the address of the memory. The DDR PSRAM also includes a data transmitter and a data strobe generating unit. The data transmitter obtains data stored in the address of the memory and provides a double data rate data to the controller according to the obtained data, and the data strobe generating unit a data strobe signal to the controller and toggling the data strobe signal in response to the double data rate data.

Abstract: A semiconductor memory system includes a first semiconductor memory die and a second semiconductor memory die. The first semiconductor memory die includes a primary data interface to receive an input data stream during write operations and to deserialize the input data stream into a first plurality of data streams, and also includes a secondary data interface, coupled to the primary data interface, to transmit the first plurality of data streams. The second semiconductor memory die includes a secondary data interface, coupled to the secondary data interface of the first semiconductor memory die, to receive the first plurality of data streams.

Abstract: Methods of operating a memory device and memory devices are provided. For example, a method of operating a memory array is provided that includes a synchronous path and an asynchronous path. A Write-with-Autoprecharge signal is provided to the synchronous path, and various bank address signals are provided to the asynchronous path. In another embodiment, the initiation of the bank address signals may be provided asynchronously to the assertion of the Write-with-Autoprecharge signal.

Abstract: A semiconductor memory device includes a system clock input block configured to be inputted with a system clock, a data clock input block configured to be inputted with a data clock, a first phase detection block configured to compare a phase of the system clock, generate a first phase detection signal, and determine a logic level of a reverse control signal in response to the first phase detection signal, a second phase detection block configured to compare a phase of a clock acquired by delaying the system clock by a correction time, generate a second phase detection signal, and determine a logic level of a clock select signal in response to the first and second phase detection signals, and a clock select block configured to select and output the data clock or a clock acquired by delaying the data clock.

Abstract: Systems and methods to set a voltage value associated with a communication bus that includes memory controller coupled to a memory device are disclosed. A particular method may include performing a first calibration operation associated with first data written from a memory controller to a memory device. A second calibration operation may be associated with second data read at the memory controller from the memory device. The operating parameter may be set based on a result of at least one of the first and the second calibration operations at the memory device or the memory controller.

Abstract: A method of monitoring signals is disclosed, wherein a plurality of command signals and address signals are consecutively expressed, as a measurement target. The method includes setting a strobe timing that has a predetermined initial value; calculating an error rate by monitoring the plurality of command signals, in accordance with the strobe timing; monitoring the plurality of address signals, and calculating a burst rate from a difference between the consecutive plurality of address signals, in accordance with the strobe timing; identifying timing where the calculated error rate and calculated burst rate are both optimized; and in the event the timing where both the calculated error rate and calculated burst rate are optimized cannot be identified, altering a predetermined value of the set strobe timing, and repeating the calculating, monitoring, and identifying.

Abstract: Clock signal generation circuitry. A frequency multiplier is coupled to receive a clock signal and to generate a frequency-multiplied clock signal. A switching circuit is coupled to receive at least two reference clock signals. The switching circuit provides one of the reference clock signals in response to a reference select signal. A phase locked loop (PLL) is coupled to receive the frequency-multiplied clock signal and the selected reference clock signal. The PLL generates an output clock signal.

Abstract: A memory system includes a plurality of memory devices having data terminals that are commonly connected to a memory controller. Each of the memory devices includes a data output circuit that outputs read data that is read from a memory cell array in response to a read command to the data terminal, and an output-timing adjustment circuit that adjusts an output timing of read data that is output from the data output circuit. The memory controller sets an adjustment amount of adjustment performed by an output-timing adjustment circuit such that delay times from when the read command is issued until when the read data is received match in the memory devices, by issuing a setting command to each of the memory devices.

Abstract: A DDR memory controller is described wherein a core domain capture clock is created by programmably delaying the core clock of the memory controller. The delay of this capture clock is typically calibrated during a power on the initialization sequence in concert with a DDR memory in a system environment, thereby minimizing the effects of system delays and increasing both device and system yield. An additional embodiment also includes programmably delaying the incoming dqs signal. To compensate for voltage and temperature variations over time during normal operation, a runtime dynamic calibration mechanism and procedure is also provided.

Abstract: A nonvolatile memory device is provided relating to a test operation for a Low Power Double-Data-Rate (LPDDR) nonvolatile memory device. The nonvolatile memory device comprises a command decoder configured to decode a test mode signal in a test mode to output program and erasure signals into a memory, an address decoder configured to decode a command address inputted through an address pin in the test mode to output a cell array address into the memory, and an overlay window configured to store a data inputted through a data pin in the test mode.

Abstract: A Registered DIMM (RDIMM) system with reduced electrical loading on the data bus for increases memory capacity and operation frequency. In one embodiment, the data bus is buffered on the DIMM. In another embodiment, the data bus is selectively coupled to a group of memory chips via switches.

Abstract: A double data rate pseudo SRAM (DDR PSRAM) is provided. The DDR PSRAM includes a data receiver, a memory and an address decoder. The data receiver receives a first single data rate data from a controller via a common bus according to a clock, and receives a double data rate data from the controller via the common bus according to a data strobe signal from the controller. The address decoder decodes the first single data rate data to obtain an address of the memory. The data receiver stores the double data rate data into the address of the memory.

Abstract: A shift circuit of a semiconductor device reduces the power consumption of the semiconductor device. The shift circuit comprises a plurality of shifters and a plurality of clock controllers. The plurality of shifters shifts an input signal in sequence in response to a clock. The plurality of clock each supply the clock to a corresponding shifter before an input of the corresponding shifter is activated and stop the supply of the clock to the corresponding shifter when an output of the corresponding shifter is activated.

Abstract: A system, includes a controller including a plurality of first external terminals configured to supply a command, a clock signal and an address, and communicate a data, and communicate a strobe signal related to the data, and a semiconductor memory device including a plurality of second external terminals corresponding to the plurality of first external terminals, one of the plurality of first external terminals and one of the plurality of second external terminals transferring an information specifying a length of a preamble of the strobe signal before the semiconductor memory device communicates the data,

Abstract: A memory apparatus is configured to generate refresh addresses with different values in response to one refresh command and an address, and perform a plurality of refresh operations with time differences in response to the refresh addresses. Herein, the refresh operations are performed within a refresh row cycle time.

Abstract: A data output circuit of a semiconductor memory apparatus includes: a data control driver configured to drive rising data and falling data to output control rising data and control falling data or drive level data to output the control rising data and the control falling data, in response to an output level test signal; a DLL clock control unit configured to drive a rising clock and a falling clock to output a control rising clock and a control falling clock in response to an enable signal and the output level test signal; and a clock synchronization unit configured to synchronize the control rising data and the control falling data with the control rising clock and the control falling clock to output serial rising data and serial falling data.

Abstract: A memory device can include a random access memory array configured to store data values; a plurality of bi-directional ports, configured to transfer data values into and out of the memory device on rising and falling transitions of at least one access clock signal; and at least one address bus configured to receive at least a portion of address values to random access locations on rising and falling transitions a timing clock signal having the same frequency as the access clock signal.

Abstract: An integrated circuit may include memory interface circuitry that is used to communicate with off-chip memory. The memory interface circuitry may include data strobe (DQS) enable circuitry that receives DQS signals from the off-chip memory and that outputs a gated version of the DQS signals. The DQS enable circuitry may include an input buffer, a comparator, a latch, a flip-flop, a counter, and a gating circuit. The input buffer may receive an incoming DQS signal. The comparator may be used to determine when the incoming DQS signal starts to toggle. The latch may be used to control when a gating signal is asserted. The flip-flop controls the counter, which limits the duration that the gating signal is asserted. The gating circuit receives the DQS signal from the buffer and the gating signal and passes the DQS signal through to its output only when the gating signal is asserted.

Abstract: Embodiments of a data capture system and method may be used in a variety of devices, such as in memory controllers and memory devices. The data capture system and method may generate a first set of periodic signals and a second set of periodic signals that differs from the first set. Either the first set of periodic signals or the second set of periodic signals may be selected and used to generate a set of data capture signals. The selection of either the first set or the second set may be made on the basis of the number of serial data digits in a previously captured burst of data. The data capture signals may then be used to capture a burst of serial data digits.

Abstract: Described herein are embodiments of selectively setting a memory command clock as a memory buffer reference clock. An apparatus configured for setting a memory command clock as a memory buffer reference clock may include a memory buffer configured to interface between a host and memory, and reference clock selection logic configured to selectively set a memory command clock as a memory buffer reference clock. Other embodiments may be described and/or claimed.

Abstract: In one embodiment, a semiconductor memory device receives a refresh command and address information, and supplies a refresh control signal and the address information in common to core chips. Each of the core chips includes a layer-address comparison circuit that determines whether the address information assigns an own core chip, and a refresh control circuit that refreshes an own memory cell based on the refresh control signal when the address information assigns the own core chip. With this arrangement, a memory capacity of a chip that is refreshed by a refresh command for one time is reduced, and therefore a shortest issuing interval of a refresh command can be shortened.

Abstract: Provided is a semiconductor integrated circuit according to an exemplary aspect of the present invention including a data transmitting circuit and a data receiving circuit that receives data transmitted from the data transmitting circuit. The data transmitting circuit includes a data output circuit that outputs the data or sets an output to a high impedance state, and a control circuit that outputs a control signal to the data output circuit so that the data output circuit outputs the data when the data transmitting circuit transmits the data, and the data output circuit keeps outputting data last output in the previous data transmission, during a predetermined period after the previous data transmission when the data transmitting circuit further transmits another data after transmitting the data.

Abstract: A device and method to perform memory operations at a clock domain crossing is disclosed. In a particular embodiment, a method includes providing a first clock signal to a write clock input of a memory to write data to the memory. The data is read from the memory according to a second clock signal that is different from the first clock signal. A third clock signal is provided to a read clock input of the memory. The third clock signal has a frequency that is substantially an integer multiple of a frequency of the second clock signal. The integer multiple is greater than one.

Abstract: Power management of an embedded dynamic random access memory (eDRAM) using collected performance counter statistics to generating a set of one or more eDRAM effectiveness predictions. Using a set of one or more eDRAM effectiveness thresholds, each corresponding to one of the set of eDRAM effectiveness predictions, to determine whether at least one eDRAM effectiveness prediction has crossed over threshold. In the case that at least one eDRAM effectiveness prediction has crossed over its threshold, transitioning the eDRAM to a new power state. Power management is achieved by transitioning to a power-off state or self-refresh state and reducing the amount of power consumed by the eDRAM as compared to a power-on state.

Abstract: Hardware-based methods and apparatus are provided for training high speed data links used in data transfer applications. A data valid window is calibrated on one or more high speed links by determining an offset delay value for at least one datapath using a finite state machine, wherein the offset delay value is based on a maximum offset delay value and a minimum offset delay value for the at least one datapath; and delaying a read data strobe signal based upon a base delay and the offset delay value for the at least one datapath. The offset delay value can be, for example, an average of the maximum offset delay and the minimum offset delay. The received pattern can be a predefined pattern or a programmable pattern. In addition, the received pattern can cover single-bit transitions and/or multi-bit transitions.

Abstract: A circuit is configured to be operatively coupled to a plurality of memory devices arranged into one or more logical ranks. Each logical rank may correspond to a set of at least two physical ranks. The circuit is configured to be operatively coupled to a memory controller of a computer system to receive a logical rank refresh command. In response, the circuit can initiate a first refresh operation for one or more first physical ranks and then initiate a second refresh operation for one or more second physical ranks. The circuit can further include a memory location storing a refresh time (tRFC) value accessible by the memory controller and based at least in part on a calculated maximum amount of time for refreshing the logical rank.

Abstract: An asynchronously pipelined SDRAM has separate pipeline stages that are controlled by asynchronous signals. Rather than using a clock signal to synchronize data at each stage, an asynchronous signal is used to latch data at every stage. The asynchronous control signals are generated within the chip and are optimized to the different latency stages. Longer latency stages require larger delays elements, while shorter latency states require shorter delay elements. The data is synchronized to the clock at the end of the read data path before being read out of the chip. Because the data has been latched at each pipeline stage, it suffers from less skew than would be seen in a conventional wave pipeline architecture. Furthermore, since the stages are independent of the system clock, the read data path can be run at any CAS latency as long as the re-synchronizing output is built to support it.

Abstract: A bus driver circuit divides an internal data bus for an integrated circuit memory into at least two groups, designated by speed. A faster group of data lines and a slower group of data lines are placed in an interleaved fashion in order to provide a two group shielding solution. At the earliest opportunity following the reception of a read command, the data from memory banks in the memory is sorted into these two groups. For a DDR3 memory, the sorting method is based on the A2 column address, known as C2. All of the data is brought out of the banks in parallel and sorted as it enters the main amplifiers. These main amplifiers are also divided into two groups, faster and slower. Each amplifier then connects to a data line (G-line) of the same group. The clock assigned to the fast group fires right away, thereby connecting the data associated with the fast amplifiers to the fast data group. This data group then proceeds to the output buffers through the entire data path as fast as possible.

Abstract: A controller for a DDR PSRAM is provided. The controller includes a single rate processing unit, a double rate processing unit and a selector. The signal rate processing unit obtains a single data rate data according to a first data and a first clock. The double rate processing unit obtains a double data rate data according to a second data and a second clock that is two times the frequency of the first clock. The selector selectively provides any of the single data rate data and the double data rate data to the DDR PSRAM via a common bus according to a control signal.

Abstract: A non-volatile memory device is operated by outputting data in response to an alternating sequence of first and second edges of a read control signal, respectively. A determination is made whether the read control signal and a write control signal are in synchronization at one of the first edges. Output of the data is stopped at the second edge that follows the one of the first edges of the read control signal if the read control signal and the write control signal are in synchronization at the one of the first edges.

Abstract: A digital memory system includes a memory controller having a driver configured for generating a digital signal. A memory module has a receiver in communication with the driver. The driver is configured for selectively directing the digital signal to the receiver of the memory module. A voltage control module is configured for determining a traffic intensity at which the digital signal is directed to the receiver and dynamically adjusting the reference voltage as a function of the traffic intensity at which the digital signal is directed to the receiver.

Abstract: A memory device can include a plurality of double data rate data (DDR) ports, each configured to receive write data and output read data on a same set of data lines independently and concurrently in synchronism with at least a first clock signal; an address port configured to receive address values on consecutive, different transitions of a second clock, each address value corresponding to an access on a different one of the data ports; and a memory array section comprising a plurality of banks, each bank providing pipelined access to storage locations therein.

Abstract: Integrated circuits may communicate with off-chip memory. Such types of integrated circuits may include memory interface circuitry that is used to interface with the off-chip memory. The memory interface circuitry may be calibrated using a procedure that includes read calibration, write leveling, read latency tuning, and write calibration. Read calibration may serve to ensure proper gating of data strobe signals and to center the data strobe signals with respect to read data signals. Write leveling ensures that the data strobe signals are aligned to system clock signals. Read latency tuning serves to adjust read latency to ensure optimum read performance. Write calibration may serve to center the data strobe signals with respect to write data signals. These calibration operations may be used to calibrate memory systems supporting a variety of memory communications protocols.

Abstract: For example, a semiconductor device includes latch circuits, whose input nodes are connected to an input selection circuit and whose output nodes are connected to an output selection circuit; and a control circuit, which controls the input selection circuit and the output selection circuit. The control circuit includes a shift register to generate an input pointer signal and a binary counter to generate an output pointer signal. The input selection circuit selects one of the latch circuits on the basis of a value of the input pointer signal. The output selection circuit selects one of the latch circuits on the basis of a value of the output pointer signal. Therefore, it is possible to prevent a hazard from occurring in the input selection circuit, as well as to reduce the number of signal lines that transmit the output pointer signal.

Abstract: A memory module comprises a plurality of semiconductor memory devices each having a termination circuit for a command/address bus. The semiconductor memory devices are formed in a substrate of the memory module, and they operate in response to a command/address signal, a data signal, and a termination resistance control signal.

Abstract: Circuits, methods, and apparatus that vary one or more attributes or parameters of a closed-loop clock circuit as a function of a characteristic of its operating frequency. One example provides a delay-locked loop having a loop bandwidth that can be varied as a function of its operating frequency. In this specific example, operating frequency is determined. This determination may be made directly, either by measuring operating frequency, or indirectly, by taking a measurement or reading, such as by reading a value for column address select latency. Once the operating frequency is determined, the loop bandwidth can be set. In one example, the loop bandwidth is set by adjusting the depth of the delay-locked loop's loop filter.