Qualcomm Incorporated

Arm Physical Ip, Inc.

Jan Christian Diffenderfer

Yuehchun Claire Cheng

Vaishnav Srinivas

David Ian West

Yu Song

Nan Chen

Jonathan H Liu

Guneet Singh

Philip Michael Clovis

Michael Thomas Fertsch

Robert Won Chol Kim

Paul Lawrence Viani

Shraddha Sridhar

Jasmin Smaila Ibrahimovic

Carlos Auyon

Systems and methods for delaying a signal are described herein. In one embodiment, a method for delaying a signal comprises receiving a first signal edge, and, in response to receiving the first signal edge, counting a number of oscillations of an oscillator. The method also comprises outputting a second signal edge if the number of oscillations reaches a predetermined number. The second signal edge represents a delayed version of the first signal edge.

Delay structure for a memory interface

Programmable delay circuits are described herein according to embodiments of the present disclosure. In one embodiment, a delay circuit comprises a plurality of delay stages coupled in series. Each of the delay stages comprises a delay gate on a forward path of the delay circuit, wherein the delay gate is configured to pass or block a signal on the forward path depending on a logic state of a respective select signal. Each of the delay stages also comprises a multiplexer on a return path of the delay circuit, wherein the multiplexer is configured to pass a signal on the return path or route the signal on the forward path to the return path depending on the logic state of the respective select signal. Output logic states of the delay gates and the multiplexers may remain static during a change in the delay setting of the delay circuit to reduce glitch.

Programmable delay circuit for low power applications

Systems and methods for delay control are described herein. In one embodiment, a delay system comprises a first delay circuit configured to provide a voltage bias to a second delay circuit, wherein the voltage bias controls a delay of the second delay circuit, and to update the voltage bias at an update rate. The delay system also comprises an update controller configured to adjust the update rate of the first delay circuit. For example, the update controller may adjust the update rate based on timing requirements of a memory interface incorporating the delay system. The update rate may be reduced when the timing requirements are more relaxed to reduce power, and may be increased when the timing requirements are tighter.

Programmable power for a memory interface

Systems and methods for delay control are described herein. In one embodiment, a delay circuit comprises a first delay path and a second delay path. The delay circuit also comprises a plurality of switches, wherein each switch is coupled between different points on the first and second delay paths, and each switch is configured to turn on or off in response to a respective one of a plurality of select signals. The delay circuit further comprises a multiplexer having a first input coupled to an output of the first delay path, a second input coupled to an output of the second delay path, and an output coupled to an output of the delay circuit, wherein the multiplexer is configured to selectively couple one of the outputs of the first and second delay paths to the output of the delay circuit in response to a second select signal.

Delay circuit

Systems and methods for recovering clock and data from a data input signal are disclosed that sample a plurality of clock phase signals with the data input signal to determine a timing relationship between the data input signal and the clock phase signals and use the determined to timing relationship to select one of the clock phase signals to use for sampling the data input signal to produce recovered data. The CDR can include a glitch suppression module to suppress glitches on the clock output signal that could be caused by large instantaneous jitter on the data input signal. A clock and data recovery circuit (CDR) using these methods can quickly lock to a new data input signal and can reliably receive data when there is large instantaneous timing jitter on the data input signal.

Clock and data recovery with high jitter tolerance and fast phase locking

A single-ended comparator is disclosed herein. The comparator may be implemented with low-voltage semiconductor devices that are capable of operating with high-voltage signals at an input. The single-ended comparator may be integrated in a larger circuit to receive and detect information provided on the input at voltage levels higher than the levels supported by the rest of the circuit, and transfer the information in the received signal for use by the rest of the circuit.

Single-ended high voltage input-capable comparator circuit

A master measure circuit is disclosed that may select from various nodes on a delay path carrying a signal. The master measure circuit measures the delay for propagation of the signal from one selected node to another selected node and controls an adjustable delay circuit in the delay path accordingly.

Measure-based delay circuit

A constant impedance driver provides controlled output slew rates. The driver includes a plurality of buffers, each with an output impedance that is multiple of the output impedance of the driver. Outputs of buffers are coupled in parallel to form the output of the driver. Inputs to the buffers are coupled to an input signal or delayed versions of the input signal. The buffer inputs may be selectively coupled to taps of a delay line to provide selected slew rates on the output of the driver. The buffers may be selectively enabled to change or calibrate the output impedance of the driver.

Constant impedance line driver with digitally controlled edge rate

In accordance with an aspect of an input/output device for providing fast translation between differential signals from a core of an integrated circuit and higher voltage signals that are external to the core, an I/O buffer includes low voltage devices for receiving core input signals, a cascode stage for setting a bias between the input devices and an output stage, and an output stage including a current mirror for providing a translated external output. Another aspect of the invention further includes a feedback path to cut off the current mirror to prevent static current and a keeper device to maintain an output level after cut off of the current mirror.

Growing community of inventors

Escondido, CA, United States of America

Jan Christian Diffenderfer