Qualcomm Incorporated

Ying Duan

Shih-Wei Chou

Abhay S Dixit

Chulkyu Lee

Harry Huy Dang

Jing Wu

Yasser Ahmed

Mansoor Basha Shaik

Zhi Zhu

Ohjoon Kwon

Seuk Son

Alexander Casino

Qinqing Cao

Panchami Devashya Shivarama

Todd Morgan Rasmus

Thomas Clark Bryan

Dhaval Sejpal

Da Ying

Harry Dang

A control circuit outputs a first control signal and a second control signal to a first control input and a second control input, respectively, of a programmable delay circuit. In certain aspects, the control circuit receives a rising edge of a delay control signal. In response to the rising edge of the delay control signal, the control circuit outputs a rising edge of the first control signal and a falling edge of the second control signal after the rising edge of the first control signal. The control circuit also receives a falling edge of the delay control signal. In response to the falling edge of the delay control signal, the control circuit outputs a rising edge of the second control signal and outputs a falling edge of the first control signal after the rising edge of the second control signal.

Control signal generation for a delay line

A method of synchronization using samplers includes receiving a digital control code, converting the digital control code into control signals, inputting each of the control signals to a respective one of the samplers, detecting at least one bit transition in the digital control code, generating a synchronization pulse in response to detecting the at least one bit transition in the digital control code, and inputting the synchronization pulse to clock inputs of the samplers.

Low-power synchronization using transition detection

An apparatus, including: a first signal receiver circuit including: a first reference voltage generator configured to generate a first reference voltage that tracks noise present in a supply voltage used to generate a first single-ended signal; and a first comparator configured to generate a first signal based on a comparison of the first single-ended signal and the first reference voltage.

Data communication apparatus with receiver employing transmitter supply voltage noise compensation

An input buffer includes a pair of input transistors and associated injection circuits. A first input transistor has a source coupled to a first voltage rail through a first current source and a gate coupled to a first wire of a multi-wire serial bus. Three or more resistors in a first injection circuit couple the wires of the serial bus to a first common node, which is coupled to the source of the first input transistor by a first capacitor. A second input transistor has a source coupled to the first voltage rail through a second current source and a gate coupled to a second wire of the serial bus. Three or more resistors in a second injection circuit couple the wires of the multi-wire serial bus to a second common node, which is coupled to the source of the second input transistor by a second capacitor.

Radio frequency interference common mode injection in a C-PHY receiver

A receiving apparatus includes a terminating network for a three-wire serial bus and a feedback circuit. Each wire of the three-wire serial bus may be coupled through a resistance to a common node of the terminating network. The feedback circuit has a first amplifier circuit having an input coupled to the common node, a comparator that receives an output of the first amplifier circuit as a first input and a reference voltage as a second input, and a second amplifier circuit responsive to an output of the comparator and configured to inject a current through the common node.

C-PHY receiver with self-regulated common mode servo loop

Methods, apparatus, and systems provide improved throughput on a communication link. An apparatus has a plurality of line drivers, a first wire state encoder configured to receive a first symbol in a sequence of symbols when a 3-wire link is in a first signaling state, and to define a second signaling state for the 3-wire link based on the first symbol and the first signaling state, a second wire state encoder configured to receive a second symbol in the sequence of symbols, and to define a third signaling state for the 3-wire link based on the second symbol and the second signaling state. The first symbol immediately precedes the second symbol in the sequence of symbols. The 3-wire link transitions from the first to the second signaling state, and from the second to the third signaling state in consecutive transmission intervals.

C-PHY half-rate wire state encoder and decoder

Methods, apparatus, and systems for communication over a multi-wire, multi-phase interface are disclosed. A clock recovery method includes generating a combination signal that includes transition pulses, each transition pulse being generated responsive to a transition in a difference signal representative of a difference in signaling state of a pair of wires in a three-wire bus. The combination signal is provided to a logic circuit that is configured to provide a clock signal as its output, where pulses in the combination signal cause the clock signal to be driven to a first state. The logic circuit receives a reset signal that is derived from the clock signal by delaying transitions to the first state while passing transitions from the first state without added delay. The clock signal is driven from the first state after passing a transition of the clock signal to the first state.

Small loop delay clock and data recovery block for high-speed next generation C-PHY

A receiver including a first differential sense amplifier configured to amplify an input differential data signal to generate an output differential data signal; a first set of one or more differential decision feedback equalizer (DFE) taps configured to modify the output differential data signal based on a set of one or more differential tap signals, wherein the first set of one or more differential DFE taps affect an output common mode voltage associated with the output differential data signal; and a compensation circuit configured to adjusts the output common mode voltage to compensate for the effect on the output common mode voltage by the set of one or more differential DFE taps. The compensation circuit includes reference and replica receivers to generate reference and replica output common mode voltages, and a feedback circuit to adjust the output common mode voltage based on the reference and replica output common mode voltages.

Compensation of common mode voltage drop of sensing amplifier output due to decision feedback equalizer (DFE) taps

Methods, apparatus, and systems for clock and data recovery in a C-PHY interface are disclosed. A receiving device has a plurality of differential receivers and a recovery circuit. The differential receivers are configured to generate difference signals. Each difference signal is representative of voltage difference between one pair of wires in a three-wire serial bus. The recovery circuit is configured to identify a first difference signal that has the greatest voltage magnitude among the plurality of difference signals in a first unit interval and determine signaling state of the three-wire serial bus for the first unit interval based on identity of the pair of wires corresponding to the first difference signal and polarity of the first difference signal in the first unit interval, and to generate a first edge in a clock signal responsive to a transition in the first difference signal during the first unit interval.

C-PHY data-triggered edge generation with intrinsic half-rate operation

In certain aspects, a device comprises one or more IO inputs; a first receiver coupled to a first supply voltage and the one or more IO inputs, wherein the first receiver comprises thick oxide transistors; and a high-speed circuit comprising: an isolation block coupled to the one or more IO inputs, wherein the isolation block comprises thick oxide transistors; and a second receiver coupled to the isolation block and a second supply voltage, wherein the second receiver comprises thin oxide transistors.

Seperation of low-power and high-speed analog front-end receivers

Methods, apparatus, and systems for communication over a multi-wire, multiphase interface are disclosed. A clock recovery apparatus has a plurality of pulse generating circuits, a logic circuit and a delay flipflop. Each pulse generating circuit generates transition pulses in response to transitions in one of three difference signals representative of a difference in signaling state of a pair of wires in a three-wire bus. Transitions in the difference signals can occur at boundaries between sequentially-transmitted symbols. The first logic circuit may provide a single pulse in a combination signal at each boundary between pairs of symbols by combining one or more transition pulses. The delay flipflop is configured to respond to each pulse in the combination signal by changing signaling state of a clock signal that is output by the clock recovery apparatus. The symbols may be sequentially transmitted over the three-wire bus in accordance with a C-PHY protocol.

Open-loop, super fast, half-rate clock and data recovery for next generation C-PHY interfaces

System, methods and apparatus are described that support multimode operation of a data communication interface. An apparatus includes a physical layer interface coupled to a serial bus and configurable for a high-speed mode of communication and a low-speed mode of communication, and a rate detector configured to receive a clock signal from the serial bus, and to use a reference clock to determine a unit interval representative of a data rate of the serial bus. The apparatus may also include interval calculation logic configured to determine an interval related to timing of a data signal transmitted on the serial bus, the interval having a duration expressed as a number of cycles of the reference clock. The physical layer interface may be configured to use the interval to capture data in the data signal.

MIPI D-PHY receiver auto rate detection and high-speed settle time control

Certain aspects of the present disclosure generally relate to techniques and apparatus for doubling the frequency of a signal. For example, certain aspects are directed to a phase frequency detector (PFD)-based rising-edge-delay-only frequency doubling circuit. One example frequency doubler circuit generally includes a first delay stage, a second delay stage, a first PFD, a first rising-edge-only adjustable delay cell, a second PFD, a second rising-edge-only adjustable delay cell a logic gate, and a comparator configured to compare a direct-current (DC) voltage value of an output of the logic gate with a reference voltage and control the first and second rising-edge-only adjustable delay cells based on the comparison.

Growing community of inventors

San Diego, CA, United States of America

Ying Duan