Altera Corporation

Xilinx, Inc.

Greg W Starr

Xiang Zhu

Martin Langhammer

Nitin Prasad

Chiao Kai Hwang

Kumara Tharmalingam

Leon Zheng

Edward Aung

Kang-Wei Lai

James Karp

John D Logue

Samit S Sengupta

Hugh Sungki O

Kang Wei Lai

Mohammed Fakhruddin

Mihail Iotov

Toan D Tran

Robert M Ondris

Shawn K Morrison

James J Koning

Mikhail Iotov

A multiplier-accumulator (MAC) block can be programmed to operate in one or more modes. When the MAC block implements at least one multiply-and-accumulate operation, the accumulator value can be zeroed without introducing clock latency or initialized in one clock cycle. To zero the accumulator value, the most significant bits (MSBs) of data representing zero can be input to the MAC block and sent directly to the add-subtract-accumulate unit. Alternatively, dedicated configuration bits can be set to clear the contents of a pipeline register for input to the add-subtract-accumulate unit.

Flexible accumulator in digital signal processing circuitry

A method of evaluating a layout cell for electrostatic discharge (ESD) protection can include identifying at least one feature of the layout cell for use in implementing an integrated circuit (IC) and comparing the at least one feature of the layout cell to an ESD requirement for the IC. The method can include indicating whether the feature of the layout cell complies with the ESD requirement.

Cell-level electrostatic discharge protection for an integrated circuit

A data link interface can include a programmable delay chain configured to provide an amount of delay to a first clock signal that clocks a first portion of a data path. The data link interface can include a phase interpolator configured to determine an amount of phase offset applied to a second clock signal that clocks a second portion of the data path. The data link interface further can include a latency detector coupled to the programmable delay chain and the phase interpolator. The latency detector can measure a phase difference between the first and second clock signals and vary the amount of delay applied to the first clock signal and/or the amount of phase offset on the second clock signal responsive to the phase difference.

Low latency transmitter path data link interface

A method and apparatus for clock phase alignment are described. An external clock is aligned to an internal clock by adjusting phase of the external clock. The external clock is of a physical medium attachment clock domain, and the internal clock is of a physical coding clock domain. After the aligning of the external clock to the internal clock, the external clock is maintained. The internal clock is aligned to the external clock by adjusting phase of the internal clock.

Clock phase alignment

Alignment of a clock signal to a particular phase is described. In one aspect, a method includes receiving an incoming clock signal and multiple phased clock signals, each of the phased clock signals having a different phase and a substantially same phase offset from another phased clock signal. At least one detection signal based on the incoming and phased clock signals is provided, and one or more errors contributed by noise in at least the incoming clock signal are corrected in the at least one detection signal. Based on the at least one detection signal, one of the phased clock signals is selected as the most closely aligned of the phased clock signals to the predetermined clock phase, and the selected clock signal is output.

Phase detection and aligned signal selection with multiple phases of clocks

Embodiments of an integrated circuit driver, a method for operating integrated circuit driver, and predrivers are described. In one embodiment of the integrated circuit driver, a bias control circuit provides a bias signal for a first mode and a second mode. The bias signal has a first voltage level associated with operation in the first mode and a second voltage level associated with operation in the second mode. An output driver circuit receives the bias signal. In the first mode, the output driver circuit operates as a supply referenced driver, and in the second mode, the output driver circuit operates as a ground referenced driver.

Output driver and operation thereof

A system and method facilitates the implementation of analog circuitry in electronic programmable devices. A user can specify user measurable parameters for analog features of the circuit, without requiring knowledge of the internal way in which those analog circuit are implemented in the programmable device to achieve desired properties of the analog parameters of interest. The implementation can be performed in different devices which may implement the analog circuit in vastly different ways.

System and method for design entry and synthesis in programmable logic devices

Preventing transistor damage to an integrated circuit is described. The circuit includes a switch with a first pair of p-type transistors respectively coupled in source-drain parallel with second pair of p-type transistors for preventing Negative Bias Temperature Instability ('NBTI') damage to the second pair of p-type transistors. The switch is configured to such that when in a state associated with causing, or potentially causing, NBTI damage, both of the second pair of p-type transistors are in an OFF state for preventing NBTI damage thereto.

Preventing transistor damage

Circuits, methods, and apparatus that provide a sequential start-up of outputs of an oscillator following a power-up or restart. The outputs are gated by enable signals. These enable signals are derived sequentially, the first in a series being triggered by a specific output of the oscillator.

Sequential VCO phase output enabling circuit

In one aspect, an embodiment provides a clock loss sense and switchover circuit and method in which clock switchover is responsive to loss of a primary signal and to additional switch command signaling. In another aspect, an embodiment provides a clock loss sense circuit and method that utilizes counters and reset signals to compare a primary clock and secondary clock signal.

Clock loss detection and switchover circuit

An integrated circuit including a phase lock loop or delay lock loop) (PLL/DLL) circuit comprising: a clock input terminal for accepting a clock signal; a phase/frequency detector (PFD) circuit including a reference clock input connected to the clock input terminal and including a PFD feedback input and including a PFD output; a charge pump (CP) circuit; at least one external feedforward output terminal; a loop filter (LF); a loop controlled signal source (LCSS); and a feedback circuit connected between a LCSS output and the PFD feedback input, the feedback circuit including, an external feedback input terminal; first frequency selection circuitry to produce a first programmable feedback signal; second frequency selection circuitry to produce a second feedback signal; and multiplex circuitry connected with the LCSS output, the external feedback input terminal and the first and second frequency selection circuitry, to cause either the first programmable feedback signal or the second programmable feedback signal to be coupled to the PFD feedback input.

PLL/DLL circuitry programmable for high bandwidth and low bandwidth applications

Integrated circuits are stabilized by monitoring changes that affect circuit operation and by compensating for those changes using power supply adjustments. Changes in operating temperature and threshold voltage changes may be measured. Differential measurements may be made in which threshold voltages measured in continuously-biased monitoring circuits are compared to threshold voltages measured in intermittently-biased monitoring circuits. Temperature changes may be monitored using a temperature monitoring circuit based on an adjustable current source and a diode. Monitoring and compensation circuitry on the integrated circuits may use analog-to-digital and digital-to-analog converters controlled by a control unit to make temperature and threshold voltage measurements and corresponding compensating changes in power supply voltages.

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Boulder, CO, United States of America

Greg W Starr