Rambus Patent Applications

Selectable-Tap Equalizer

Granted: March 12, 2009
Application Number: 20090067484
A signaling circuit having a selectable-tap equalizer. The signaling circuit includes a buffer, a select circuit and an equalizing circuit. The buffer is used to store a plurality of data values that correspond to data signals transmitted on a signaling path during a first time interval. The select circuit is coupled to the buffer to select a subset of data values from the plurality of data values according to a select value. The equalizing circuit is coupled to receive the subset of…

Selectable-Tap Equalizer

Granted: March 12, 2009
Application Number: 20090067482
A signaling circuit having a selectable-tap equalizer. The signaling circuit includes a buffer, a select circuit and an equalizing circuit. The buffer is used to store a plurality of data values that correspond to data signals transmitted on a signaling path during a first time interval. The select circuit is coupled to the buffer to select a subset of data values from the plurality of data values according to a select value. The equalizing circuit is coupled to receive the subset of…

Memory Controller With Multi-Modal Reference Pad

Granted: March 5, 2009
Application Number: 20090059642
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…

Selectable-Tap Equalizer

Granted: March 5, 2009
Application Number: 20090060017
A signaling circuit having a selectable-tap equalizer. The signaling circuit includes a buffer, a select circuit and an equalizing circuit. The buffer is used to store a plurality of data values that correspond to data signals transmitted on a signaling path during a first time interval. The select circuit is coupled to the buffer to select a subset of data values from the plurality of data values according to a select value. The equalizing circuit is coupled to receive the subset of…

Methods and systems for operating memory in two modes

Granted: February 19, 2009
Application Number: 20090049324
A memory system permits synchronized transmission of data with multiple memory modules in a dynamically expandable bus system such as with a point-to-point memory bus using strobed data transmission. Memory modules of the system are selectively configured to switch transmission modes to either transmit data to a memory controller or a timing reference signal to another memory module from a common terminal coupled to a common path of the bus which may depend on the number of memory…

Methods and apparatus for strobe signaling and edge detection thereof

Granted: February 5, 2009
Application Number: 20090034344
A data system component having a state machine circuit and receivers that utilize high and low threshold signals permits accurate detection of strobe signal pattern edges such as those for preamble, burst and post-amble conditions in the strobe signal. The state machine circuit may then be configured to set conditions associated with further circuit elements such as for power saving, data reception, on-die termination, etc. based on the conditions detected in the strobe signal to improve…

PERIODIC CALIBRATION FOR COMMUNICATION CHANNELS BY DRIFT TRACKING

Granted: February 5, 2009
Application Number: 20090034669
A method and system that provides for execution of a first calibration sequence, such as upon initialization of a system, to establish an operation value, which utilizes an algorithm intended to be exhaustive, and executing a second calibration sequence from time to time, to measure drift in the parameter, and to update the operation value in response to the measured drift. The second calibration sequence utilizes less resources of the communication channel than does the first…

Multi-drop bus system

Granted: February 5, 2009
Application Number: 20090037626
A multi-drop bus system and a method for operating such a system. The system includes a multi-drop bus having at least one bus line, each bus line being made up of a multiple of line segments. Each of the line segments terminates at a drop point and each drop point is coupled to a load impedance. The characteristic impedance of a line segment is matched to the equivalent impedance presented by the load impedance in combination with the characteristic impedance of a following segment, or…

CONTINUOUS TIMING CALIBRATED MEMORY INTERFACE

Granted: January 29, 2009
Application Number: 20090031091
A system that adjusts the timing of write operations at a memory controller is described. This system operates by observing timing drift for read data at the memory controller, and then adjusting the timing of write operations at the memory controller based on the observed timing drift for the read data.

Phase Controlled Oscillator Circuit with Input Signal Coupler

Granted: January 15, 2009
Application Number: 20090015340
An oscillating signal in an oscillator is caused to phase shift toward the phase of an input signal coupled to the oscillating signal. The resonant frequency of the oscillator is about equal to an integer multiple of the frequency of the input signal. The input signal may be generated in a pulse generator to have an input pulse duration less than or equal to that of the oscillating signal. The oscillator circuit may be used as a filter to filter pulse width variations or to filter jitter…

Integrated Circuit Memory Device, System And Method Having Interleaved Row And Column Control

Granted: November 13, 2008
Application Number: 20080279032
An integrated circuit memory device, system and method embodiments decode interleaved row and column request packets transferred on an interconnect at a first clock frequency. Separate row decode logic and column decode logic, clocked at a relatively slower second clock frequency, output independent column and row control internal signals to a memory core in response to memory commands in the request packets. An integrated circuit memory device includes an interface having separate row…

HIGH-SPEED COMMUNICATION SYSTEM WITH A FEEDBACK SYNCHRONIZATION LOOP

Granted: November 6, 2008
Application Number: 20080273647
In a communications device having a physical layer device and a processing device connected to the physical layer device, the number of input/output (I/O) ports required for communication between the devices in the gigabit range is substantially reduced by utilizing millivolt differential I/O drivers and receivers. In addition, a calibration feedback loop synchronizes the data and clock signals on the processing device, thereby eliminating the need to recover the clock on the processing…

Adaptive-Allocation Of I/O Bandwidth Using A Configurable Interconnect Topology

Granted: November 6, 2008
Application Number: 20080276020
Apparatus and methods allocate I/O bandwidth of an electrical component, such as an IC, by configuring an I/O interface into various types of interfaces. In an embodiment of the present invention, an I/O interface is configured into either a bi-directional contact, unidirectional contact (including either a dedicated transmit or dedicated receive contact) or a maintenance contact used in a maintenance or calibration mode of operation. The I/O interface is periodically reconfigured to…

SINGLE-CLOCK, STROBELESS SIGNALING SYSTEM

Granted: October 30, 2008
Application Number: 20080267000
A signaling system includes a signaling path, a master device coupled to the signaling path, a slave device coupled to the signaling path, and a clock generator. The slave device includes timing circuitry to generate an internal clock signal having a phase offset relative to a clock signal supplied by the clock generator, the phase offset being determined at least in part by a signal propagation time on the signal path.

Equalizing Transceiver With Reduced Parasitic Capacitance

Granted: September 18, 2008
Application Number: 20080224739
A signaling circuit having reduced parasitic capacitance. The signaling circuit includes a plurality of driver circuits each having an output coupled to a first output node, and a plurality of select circuits each having an output coupled to a control input of a corresponding one of the driver circuits. Each of the select circuits includes a control input to receive a respective select signal and a plurality of data inputs to receive a plurality of data signals. Each of the select…

Memory System And Device With Serialized Data Transfer

Granted: August 28, 2008
Application Number: 20080209141
A memory system with serialized data transfer. The memory system includes within a memory controller and a plurality of memory devices. The memory controller receives a plurality of write data values from a host and outputs the write data values as respective serial streams of bits. Each of the memory devices receives at least one of the serial streams of bits from the memory controller and converts the serial stream of bits to a set of parallel bits for storage.

Early Read After Write Operation Memory Device, System And Method

Granted: July 24, 2008
Application Number: 20080175070
A memory device, system and method for allowing an early read operation after one or more write operations is provided according to an embodiment of the present invention. The memory device comprises an interface for providing a first write address, a first write data, and a read address. A memory core is coupled to the interface and includes a first memory section having a first data path and a first address path and a second memory section having a second data path and a second address…

METHOD AND APPARATUS FOR ADJUSTING THE PERFORMANCE OF A SYNCHRONOUS MEMORY SYSTEM

Granted: July 3, 2008
Application Number: 20080162759
A method and apparatus for adjusting the performance of a memory system is provided. A memory system comprises a master device and a slave device. A memory channel couples the master device to the slave device such that the slave device receives the system operating information from the master device via the memory channel. The slave device further includes means for tuning circuitry within the slave device such that the performance of the memory system is improved.

System To Detect And Identify Errors In Control Information, Read Data And/Or Write Data

Granted: July 3, 2008
Application Number: 20080163007
An integrated circuit, such as an integrated circuit memory or buffer device, method and system, among other embodiments, generate a plurality of error codes, such as CRC codes, corresponding to control information, write data and read data transactions, respectively. The plurality of separately generated CRC codes is logged or stored in respective storage circuits, such as circular buffers. The stored plurality of CRC codes corresponding to each transaction then may be used to determine…

Memory Module Including A Plurality Of Integrated Circuit Memory Devices And A Plurality Of Buffer Devices In A Matrix Topology

Granted: June 19, 2008
Application Number: 20080144411
A memory module includes a plurality of signal paths that provide data to a memory module connector interface from a plurality of respective integrated circuit buffer devices that access data from an associated plurality of integrated circuit memory devices. The memory module forms a plurality of “data slices” or a plurality of portions of the memory module data bus that is coupled to the respective integrated circuit buffer devices. Each integrated circuit buffer device is also…