Patent application number | Description | Published |
20090059642 | Memory Controller With Multi-Modal Reference Pad - A memory controller operates in two modes to support different types of memory devices. In a first mode, the memory controller distributes a dedicated reference voltage with each of a plurality of signal bundles to a corresponding plurality of memory devices. The reference voltages are conveyed using pads that are alternatively used for e.g. timing-reference signals in a second mode, so the provision for bundle-specific reference voltages need not increase the number of pads on the memory controller. | 03-05-2009 |
20090089557 | UTILIZING MASKED DATA BITS DURING ACCESSES TO A MEMORY - Embodiments of an apparatus that uses unused masked data bits during an access to a memory are described. This apparatus includes a selection circuit, which selects data bits to be driven on data lines during the access to the memory. This selection circuit includes a control input that receives a data mask signal, which indicates whether a set of data bits is to be masked during the access to the memory. During the access to the memory, the selection circuit selects either the set of data bits to be driven when the data mask signal is not asserted, or an alternative set of values to be driven when the data mask signal is asserted. | 04-02-2009 |
20100309964 | ASYMMETRIC COMMUNICATION ON SHARED LINKS - Embodiments of a system that communicates bidirectional data between two devices via shared links is described. In this system, data is transmitted on the shared links by one of the devices using single-ended drivers, and corresponding symbols are received on the shared links by the other device using differential comparison circuits. The data may be encoded as a series of parallel codewords prior to transmission. Each shared link may communicate a respective symbol in each codeword, which can have one of two possible logical values (e.g., a logic 0 or a logic 1). The corresponding symbols received by the other device may comprise a parallel symbol set, and each of the differential comparison circuits may compare symbols received on pairs of the shared links. A decoder in the other device may decode a respective parallel symbol set from the outputs of the differential comparison circuits to recover the encoded data. | 12-09-2010 |
20110051854 | ERROR DETECTION AND OFFSET CANCELLATION DURING MULTI-WIRE COMMUNICATION - Embodiments of a circuit are described. In this circuit, a receive circuit includes M input nodes that receive a set of M symbols on M links during a time interval, where the set of M symbols are associated with a codeword. Moreover, the receive circuit includes a decoder, coupled to the M input nodes, that determines the codeword in a code space based on the set of M symbols and that decodes the codeword to a corresponding set of N decoded symbols. Additionally, the receive circuit may include a detector that detects an imbalance in a number of instances of a first value in the set of M symbols, and a number of instances of a second value in the set of M symbols, and, if an imbalance is detected, that asserts an error condition. | 03-03-2011 |
20110069782 | Capacitive-coupled Crosstalk Cancellation - This disclosure presents a method of canceling inductance-dominated crosstalk using a capacitive coupling circuit; it also presents a method of calibrating, selecting and programming a capacitance value used for coupling, so as to add a derivative of each aggressor signal to each victim signal, and thereby negate crosstalk that would otherwise be seen by a given receiver. In the context of a multiple-line bus, cross-coupling circuits may be used between each pair of “nearest neighbors,” with values calibrated and used for each particular transmitter-receiver pair. Embodiments are also presented which address crosstalk induced between lines that are not nearest neighbors, such as, for example, for use in a differential signaling system. | 03-24-2011 |
20110102043 | REDUCING POWER-SUPPLY-INDUCED JITTER IN A CLOCK-DISTRIBUTION CIRCUIT - A system for compensating for power-supply-induced jitter (PSIJ) in a chain of clock buffers within an integrated circuit is described. During operation, the system couples a first supply voltage from a first voltage source to a supply node of each clock buffer in a first chain of clock buffers. Note that a change in the first supply voltage causes a change in a first propagation delay associated with the first chain of the clock buffers. The system also couples a second chain of clock buffers in series with the first chain of clock buffers. The system then couples the first voltage source to each clock buffer in the second chain of clock buffers through coupling circuitry. Next, the system adjusts the coupling circuitry so that the change in the first supply voltage from the first voltage source causes a change in a second propagation delay associated with the second chain of the clock buffers, wherein the change in the first propagation delay and the change in the second propagation delay are complementary. | 05-05-2011 |
20110127990 | FREQUENCY RESPONSIVE BUS CODING - A data system | 06-02-2011 |
20110293041 | Receiver Resistor Network for Common-Mode Signaling - A receiver circuit to receive signals from first and second pairs of transmission lines includes first and second interfaces, each with first and second input nodes to receive respective signals. The receiver circuit also includes a resistor network with first, second, third, and fourth resistive elements. The first and second resistive elements are each connected between the input nodes of a respective interface. The third and fourth resistive elements each include a pair of resistors connected in series between the input nodes of a respective interface, and an intermediate node between the resistors. The intermediate nodes are connected to an AC ground. The receiver circuit further includes a differential amplifier with first and second inputs coupled respectively to the first and second interfaces and an output to provide a signal derived from common mode components of the signals received at the input nodes. | 12-01-2011 |
20120169412 | FAST POWER-ON BIAS CIRCUIT - Conventional bias circuits exhibit a number of limitations, including the time required to power-up a bias circuit following a low-power state. Large current surges in the supply network induce ringing, further complicating a power-up process. Example embodiments reduce power-up time and minimize current surges in the supply by selectively charging and discharging capacitance to the circuit during power-up and power-down of the bias circuit. | 07-05-2012 |
20130249612 | METHOD AND APPARATUS FOR SOURCE-SYNCHRONOUS SIGNALING - A low-power, high-performance source-synchronous chip interface which provides rapid turn-on and facilitates high signaling rates between a transmitter and a receiver located on different chips is described in various embodiments. Some embodiments of the chip interface include, among others: a segmented “fast turn-on” bias circuit to reduce power supply ringing during the rapid power-on process; current mode logic clock buffers in a clock path of the chip interface to further reduce the effect of power supply ringing; a multiplying injection-locked oscillator (MILO) clock generator to generate higher frequency clock signals from a reference clock; a digitally controlled delay line which can be inserted in the clock path to mitigate deterministic jitter caused by the MILO clock generator; and circuits for periodically re-evaluating whether it is safe to retime transmit data signals in the reference clock domain directly with the faster clock signals. | 09-26-2013 |
20130346822 | ERROR DETECTION AND OFFSET CANCELLATION DURING MULTI-WIRE COMMUNICATION - Embodiments of a circuit are described. In this circuit, a receive circuit includes M input nodes that receive a set of M symbols on M links during a time interval, where the set of M symbols are associated with a codeword. Moreover, the receive circuit includes a decoder, coupled to the M input nodes, that determines the codeword in a code space based on the set of M symbols and that decodes the codeword to a corresponding set of N decoded symbols. Additionally, the receive circuit may include a detector that detects an imbalance in a number of instances of a first value in the set of M symbols and a number of instances of a second value in the set of M symbols, and, if an imbalance is detected, that asserts an error condition. | 12-26-2013 |
20140210545 | ON-CHIP REGULATOR WITH VARIABLE LOAD COMPENSATION - An integrated circuit includes a voltage regulator to supply a regulated voltage and a data output that couples to an unterminated transmission line. The circuit draws a variable amount of power from the voltage regulator according to the data. The voltage regulator includes a first current generation circuit to provide a data transition-dependent current. | 07-31-2014 |
20140258768 | CHANGING SETTINGS FOR A TRANSIENT PERIOD ASSOCIATED WITH A DETERMINISTIC EVENT - Disclosed embodiments relate to a system that changes transmitter and/or receiver settings to deal with reliability issues caused by a predetermined event, such as a change in a power state or a clock start event. One embodiment uses a first setting while operating a transmitter during a normal operating mode, and a second setting while operating the transmitter during a transient period following the predetermined event. A second embodiment uses similar first and second settings in a receiver, or in both a transmitter and a receiver employed on one side of a bidirectional link The first and second settings can be associated with different swing voltages, edge rates, equalizations and/or impedances. | 09-11-2014 |
20140281205 | MEMORY CIRCUIT AND METHOD FOR ITS OPERATION - In an illustrative embodiment, the memory circuit includes first and second data paths on which data is transferred for read and write memory operations and first and second mixer circuits for adjusting the phase of clock signals applied to their inputs. The mixer circuits are cross-coupled so that the outputs of the first and second mixers are both available to both the first and second data paths. One mixer is used to provide a first phase adjusted clock signal for use by the operating circuit and the other mixer is used to provide a second phase adjusted clock signal for use by a following operation whatever that may be. | 09-18-2014 |