Abstract:
A method and system provides for execution of calibration cycles from time to time during normal operation of the communication channel. A calibration cycle includes de-coupling the normal data source from the transmitter and supplying a calibration pattern in its place. The calibration pattern is received from the communication link using the receiver on the second component. A calibrated value of a parameter of the communication channel is determined in response to the received calibration pattern. The steps involved in calibration cycles can be reordered to account for utilization patterns of the communication channel. For bidirectional links, calibration cycles are executed which include the step of storing received calibration patterns on the second component, and retransmitting such calibration patterns back to the first component for use in adjusting parameters of the channel at first component.
Abstract:
A memory module having reduced access granularity. The memory module includes a substrate having signal lines thereon that form a control path and first and second data paths, and further includes first and second memory devices coupled in common to the control path and coupled respectively to the first and second data paths. The first and second memory devices include control circuitry to receive respective first and second memory access commands via the control path and to effect concurrent data transfer on the first and second data paths in response to the first and second memory access commands.
Abstract:
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 calibration sequence. In one embodiment, the first calibration sequence for measurement and convergence on the operation value utilizes long calibration patterns, such as codes that are greater than 30 bytes, or pseudorandom bit sequences having lengths of 2N−1 bits, where N is equal to or greater than 7, while the second calibration sequence utilizes short calibration patterns, such as fixed codes less than 16 bytes, and for example as short as 2 bytes long.
Abstract:
In a reconfigurable data strobe-based memory system, data strobes may be re-tasked in different modes of operation. For example, in one mode of operation a differential data strobe may be used as a timing reference for a given set of data signals. In a second mode of operation, one of the components of the differential data strobe may be used as a timing reference for a first portion of the set of data signals and the other component used as a timing reference for a second portion of the set of data signals. Different data mask-related schemes also may be invoked for different modes of operation. For example, in a first mode of operation a memory controller may generate a data mask signal to prevent a portion of a set of data from being written to a memory array. Then, in a second mode of operation the memory controller may invoke a coded value replacement scheme or a data strobe transition inhibition scheme to prevent a portion of a set of data from being written to a memory array.
Abstract:
A memory module includes a substrate, plural memory devices, and a buffer. The plural memory devices are organized into at least one rank, each memory device having plural banks. The buffer includes a primary interface for communicating with a memory controller and a secondary interface coupled to the plural memory devices. For each bank of each rank of memory devices, the buffer includes data buffer circuitry and address buffer circuitry. The data buffer circuitry includes first storage to store write data transferred during a bank cycle interval (tRR). The address buffer circuitry includes second storage to store address information corresponding to the data stored in the first storage.
Abstract:
A signaling system is disclosed. The signaling system includes a first integrated circuit (IC) chip to receive a data signal and a strobe signal. The first IC includes circuitry to sample the data signal at times indicated by the strobe signal to generate phase error information and circuitry to output the phase error information from the first IC device. The system further includes a signaling link and a second IC chip coupled to the first IC chip via the signaling link to output the data signal and the strobe signal to the first IC chip. The second IC chip includes delay circuitry to generate the strobe signal by delaying an aperiodic timing signal for a first time interval and timing control circuitry to receive the phase error information from the first IC chip and adjust the first time interval in accordance with the phase error information.
Abstract:
An integrated circuit device includes a transmitter circuit including an output driver. The integrated circuit device includes a first register to store a value representative of a drive strength setting associated with the transmitter circuit such that the output driver outputs data in accordance with the drive strength setting. The integrated circuit device also includes a second register to store a value representative of an equalization setting associated with the transmitter circuit such that the output driver outputs data in accordance with the equalization setting. The integrated circuit device further includes a third register to store a value representative of a slew rate setting associated with the transmitter circuit such that the output driver outputs data in accordance with the slew rate setting.
Abstract:
A memory controller component includes transmit circuitry and adjusting circuitry. The transmit circuitry transmits a clock signal and write data to a DRAM, the write data to be sampled by the DRAM using a timing signal. The adjusting circuitry adjusts transmit timing of the write data and of the timing signal such that an edge transition of the timing signal is aligned with an edge transition of the clock signal at the DRAM.
Abstract:
An integrated circuit device includes a transmitter circuit including an output driver. The integrated circuit device includes a first register to store a value representative of a drive strength setting associated with the transmitter circuit such that the output driver outputs data in accordance with the drive strength setting. The integrated circuit device also includes a second register to store a value representative of an equalization setting associated with the transmitter circuit such that the output driver outputs data in accordance with the equalization setting. The integrated circuit device further includes a third register to store a value representative of a slew rate setting associated with the transmitter circuit such that the output driver outputs data in accordance with the slew rate setting.
Abstract:
A memory component includes a memory core comprising dynamic random access memory (DRAM) storage cells and a first circuit to receive external commands. The external commands include a read command that specifies transmitting data accessed from the memory core. The memory component also includes a second circuit to transmit data onto an external bus in response to a read command and pattern register circuitry operable during calibration to provide at least a first data pattern and a second data pattern. During the calibration, a selected one of the first data pattern and the second data pattern is transmitted by the second circuit onto the external bus in response to a read command received during the calibration.