Intel Corporation

Chi-Yeu Chao

Gregory F Taylor

Keng L Wong

Songmin Kim

Chee How Lim

Hung-Piao Ma

Tawfik Arabi

Cangsang Zhao

Mingwei Huang

Thomas D Barrett

Raymond (Hon-Mo) Law

According to embodiments of the present invention, a phase-locked loop (PLL) may include circuitry to select a wide pulse width for the phase-frequency detector control signal when the PLL is in a frequency acquisition stage, a narrow pulse width for the phase-frequency detector control signal when the PLL is in a phase capture stage, and a wide pulse width of the phase-frequency detector control signal when the PLL is in a lock stage.

Phase-locked loop having dynamically adjustable up/down pulse widths

An input circuit includes a comparator circuit and a multi-reference circuit. The input circuit receives an input signal and generates an output signal as a function of the input signal and a reference signal received from the multi-reference circuit. The comparator circuit detects a crossing of the input signal relative to the reference signal and causes a corresponding transition of the output signal. In response to the transition of the output signal, the multi-reference circuit provides a different reference signal to the comparator circuit. The reference signals provided by the multi-reference circuit are selected to create hysteresis in the operation of the input circuit.

Input circuit with switched reference signals

Input/output (I/O) clock phase adjustment circuitry for use with I/O buffer circuitry of an integrated circuit chip. In one embodiment, an integrated circuit chip includes a phase adjustment circuit coupled to receive a system clock. The phase adjustment circuit generates an I/O clock coupled to be received by an I/O buffer circuit of an integrated circuit chip for I/O data transfers in a system. The phase adjustment circuit includes a phase locked loop (PLL) circuit coupled to receive the system clock through a first delay circuit. The I/O clock generated by the PLL circuit is received through a second delay circuit at a feedback clock input of the PLL circuit. The first and second delay circuits are used to control the phase of the I/O clock generated by the PLL circuit relative to the system clock. In one embodiment, a third delay circuit is included in an I/O data path of the I/O buffer circuit of the integrated circuit. The third delay circuit enables input and output data transmissions from the integrated circuit to be clocked, in effect, out of phase with the I/O clock generated by phase adjustment circuit.

Clocking an I/O buffer, having a selectable phase difference from the system clock, to and from a remote I/O buffer clocked in phase with the system clock

An integrated circuit includes circuitry to test input/output (I/O) devices. Test data is provided to a loopback circuit that drives data through the output buffer to the pad, and back onto the integrated circuit through the input buffer. Separate clock signals, with varying phase, are generated for input synchronous elements and output synchronous elements. The phase, and the relative time delay between the separate clocks, changes as an external clock is varied. The external clock is varied to verify the performance parameters of the I/O devices. Each I/O device includes a shift register that can be coupled to the other buffers in a chain, or can be configured to be in a loop.

I/O device testing method and apparatus

An input circuit that receives an input signal and generates an output signal as a function of the input signal includes a latching circuit and a time blanking circuit. The latching circuit detects a transition of the input signal and causes a corresponding transition of the output signal. The time blanking circuit prevents the output signal from transitioning again for a predetermined period. This period begins with essentially no delay from the transition of the output signal, which can reduce the input circuit's sensitivity to high frequency noise that may be present on transitions of the input signal.

Input circuit with non-delayed time blanking

A dual mode clock input buffer is disclosed. The input buffer includes a first portion for handling a single ended high voltage clock signal and a second portion for handling a differential low voltage clock signal.

Self-configurable clock input buffer compatible with high-voltage single-ended and low-voltage differential clock signals

A clocked sense amplifier flip flop includes at least one keeper unit to prevent the occurrence of a floating data node.

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Portland, OR, United States of America

Chi-Yeu Chao