Abstract: Data coding schemes perform level-based and/or transition-based encoding to avoid signaling conditions that create worst case crosstalk during transmission of multi-bit data from one circuit to another circuit via a parallel communication link. The coding schemes disallow certain patterns from being present in the signal levels, signal transitions, or a combination of the signal levels and signal transitions that occur in a subset of the multi-bit data that corresponds to certain physically neighboring wires of the parallel communication link.

Abstract: A phase-locked loop circuit comprises a multi-phase oscillator having a plurality of coupled oscillators. A calibration module detects mismatches between frequency characteristics of the different oscillators in the phase-locked loop circuit during a calibration process. The calibration module then calibrates the various oscillators to compensate for the detected mismatch. Once calibrated, the phase-locked loop circuit can operate with little or no performance degradation despite the mismatch in frequency characteristics between the different oscillators.

Abstract: Circuitry capable of performing fractional clock multiplication by using an injection-locked oscillator is described. Some embodiments described herein perform fractional clock multiplication by periodically changing the injection location, from a set of injection locations, where the injection signal is injected and/or by periodically changing a phase, from a set of phases, of the injection signal that is injected into the ILO.

Abstract: In a signal calibration scheme, a desired phase relationship is maintained between a set of signals. For example, in some aspects the desired phase of a clock tree generated from a high speed reference clock signal may be maintained by detecting phase differences between a low speed reference clock signal and low speed clock signals associated with different phases of the clock tree. In some aspects, the desired phase of a clock tree may be maintained by detecting framing offsets that occur through the use of the clock tree.

Abstract: In a signal calibration scheme, a desired phase relationship is maintained between a set of signals. For example, in some aspects the desired phase of a clock tree generated from a high speed reference clock signal may be maintained by detecting phase differences between a low speed reference clock signal and low speed clock signals associated with different phases of the clock tree. In some aspects, the desired phase of a clock tree may be maintained by detecting framing offsets that occur through the use of the clock tree.