摘要:
A memory system uses multiple pulse amplitude modulation (multi-PAM) output drivers and receivers to send and receive multi-PAM signals. A multi-PAM signal has more than two voltage levels, with each data interval now transmitting a “symbol” at one of the valid voltage levels. In one embodiment, a symbol represents two or more bits. The multi-PAM output driver drives an output symbol onto a signal line. The output symbol represents at least two bits that include a most significant bit (MSB) and a least significant bit (LSB). The multi-PAM receiver receives the output symbol from the signal line and determines the MSB and the LSB.
摘要:
A memory system architecture/interconnect topology that includes at least one point-to-point link between a master, and at least one memory subsystem. The memory subsystem includes a buffer device coupled to a plurality of memory devices. The memory system may be upgraded through dedicated point-to-point links and corresponding memory subsystems. The master communicates to the plurality of memory devices in each memory subsystem through the respective buffer device via each point-to-point link
摘要:
A system includes a master device connected to one or more slave devices via a channel, the channel communicating an externally generated first system clock towards the master device. A delay locked loop circuit receives the first system clock and a second phase feedback signal as inputs and generates a transmit clock signal. A phase offset circuit receives the transmit system clock and generates a phase shifted version of the transmit clock signal as a second system clock. A first phase detector receives a receive system clock and the transmit system clock and generates a first phase feedback signal. A delay element receives the first system clock and the first phase feedback signal and generates a delayed first system clock. A second phase detector receives the delayed first system clock and the second system clock and generates the second phase feedback signal.
摘要:
A memory module includes an integrated circuit buffer device that receives control information via a connector interface. A first plurality of signal lines carries a first address from the integrated circuit buffer device to a first memory device. A second plurality of signal lines carries a first control signal from the integrated circuit buffer device to the first memory device. The first control signal specifies a read operation by the first memory device such that the first memory device provides first data, accessed from a memory location in the first memory device based on the first address, to the integrated circuit buffer device. A first signal line carries a first signal from the integrated circuit buffer device to the first memory device. The first signal synchronizes communication of the first control signal from the integrated circuit buffer device to the first memory device. A third plurality of signal lines carries a second address from the integrated circuit device to the second memory device. A fourth plurality of signal lines carries a second control signal from the integrated circuit buffer device to the second memory device. The second control signal specifies a read operation. The second control signal corresponds to the control information. A second signal line carries a second signal from the integrated circuit buffer device to the second memory device. The second signal synchronizes communication of the second control signal from the integrated circuit buffer device to the second memory device. A transmitter circuit is disposed on the integrated circuit buffer device.
摘要:
A memory system architecture/interconnect topology that includes at least one point-to-point link between a master, and at least one memory subsystem. The memory subsystem includes a buffer device coupled to a plurality of memory devices. The memory system may be upgraded through dedicated point-to-point links and corresponding memory subsystems. The master communicates to the plurality of memory devices in each memory subsystem through the respective buffer device via each point-to-point link
摘要:
Disclosed herein is a process-tracking clock duty cycle integrator. Common mode feedback is used to set a common mode output voltage that varies with the voltage threshold of MOS elements that implement the circuit. In addition, a buffer is used to control the common mode input voltage to the differential amplifier circuit, and to vary the common mode input voltage with the voltage threshold.
摘要:
A circuit for clocking includes an input data path, a receiver, a set of flip-flops, at least one interpolator and a controller. The receiver is coupled to the input data path for receiving input data. The flip-flops, coupled to the receiver, sample the input data. A first interpolator, coupled to one or more of the flip-flops, receives the sampled input data. The controller, coupled to the first interpolator, controls the first interpolator by providing phase information regarding the input data to the first interpolator. The circuit reduces any jitter transferred from the input path to an output path.
摘要:
A clock and data recovery circuit may comprise a first transmission line comprising a plurality of segments of a first predetermined length. The first transmission line receives and propagates a clock signal through the segments of the first predetermined length. The clock and data recovery circuit may further comprise a second transmission line comprising a plurality of segments of a second predetermined length. The second transmission line receives data from a serial bit stream and propagates the data through the segments of the second predetermined length. In some embodiments, the first or second transmission line further comprise taps to extract, from the segments of the second predetermined length, a plurality of delayed data signals. The clock and data recovery circuit may further comprise a plurality of sampling circuits, coupled to the first and second transmission lines, to generate samples from the delayed data signals and the delayed clock signals.
摘要:
Transmitter waveform dispersion penalty (“TWDP”) is decreased in a transmitter. A binary data signal is received for transmission over a channel that exhibits TWDP. The data signal is shifted less than a full clock cycle to generate at least one post cursor signal. The post cursor signal is subtracted from the data signal to generate a transmitter output data signal for transmission over the channel. In addition to decreasing TWDP, data dependent jitter is also reduced for data transmission across a channel that exhibits a multi-pole transmission characteristic. A main data signal and at least one cursor signal, which is shifted at least a portion of a clock period from the main data signal, is generated. The cursor signal is filtered to filter out effects based on the second pole of the multi-pole transmission characteristic. The main data signal is subtracted from the filtered cursor signal to generate the transmitter output data signal. Circuits and methods for transmitting serial data streams over a channel compliant with KR and SPI specifications are also disclosed.
摘要:
Methods and circuits provide function-appropriate signaling to multi-functional circuits on a constrained set of communication lines. A first communication line receives digital signals. The second communication line is employed for digital signaling related to a first function. In further steps, the method comprises initiating, based on a multi-value logic digital signal on the first communication line, an activation process that generates a second-function activation signal. Upon receipt of the second-function activation signal, the second communication line is employed for digital signaling related to a second function. Preferred activation processes involve monitoring the second communication line for a digital signature and sending the activation signal upon detection of an appropriate signature.