摘要:
A data receiver circuit having a comparator that exhibits substantially variable offset that is controllable to represent a variable reference level, without a separate input to receive a reference voltage level. The comparator output provides an indication of the comparison between a fixed voltage level applied to its differential signal input and the variable reference level. While changing an offset code that is fed to an offset control input of the comparator, and while applying a fixed voltage level that represents a symbol in the transmission line analog signal, a value of the offset code which causes the output of the comparator to change states is captured. A similar process may be repeated for different symbol values that can be transmitted, such that an indication of the voltage margin may be obtained as a difference between two captured offset codes. Circuitry to perform the process may be provided on-chip to the receiver circuit.
摘要:
An all-digital delay measurement circuit (DMC) constructed on an integrated circuit (IC) die characterizes clocking circuits such as full phase rotation interpolators, also constructed on the IC die. The on-die all-digital DMC produces a digital output value proportional to the relative delay between two clocks, normalized to the clock period of the two clocks.
摘要:
In general, in one aspect, the disclosure describes a simulator for emulating various types of device noise in time-domain circuit simulations. The simulator is capable of adding noise to transistors as well as passive elements like resistors. The simulator utilizes at least one current source in parallel to a device to emulate the noise. The current source generates a random current output to emulate the device noise based on a random Gaussian number and the standard deviation of the device noise. The noise standard deviation can be determined based on the noise power spectral density of the device having a particular bias at that simulation time and the update time. The simulator is capable of emulating any noise source with a constant or monotonically decreasing noise spectrum (e.g., thermal noise, flicker noise) by utilizing multiple current sources having different update steps. The simulator is compatible with standard circuit simulators.
摘要:
An integrated circuit compensates for power supply voltage dependent delay using a clock circuit that is responsive to a power supply voltage measuring circuit. The clock circuit modifies a phase relationship based on a measured power supply voltage value.
摘要:
According to an embodiment, an equalization loop has a comparator with an input to receive a transmission line analog signal level. The comparator has a substantially variable offset that is controllable to represent a variable reference level. An output of the comparator provides a value that represents a comparison between the transmission line analog signal level and the variable reference level.
摘要:
An all-digital delay measurement circuit (DMC) constructed on an integrated circuit (IC) die characterizes clocking circuits such as full phase rotation interpolators, also constructed on the IC die. The on-die all-digital DMC produces a digital output value proportional to the relative delay between two clocks, normalized to the clock period of the two clocks.
摘要:
Embodiments of methods and apparatus for clock and data recovery are disclosed. In some embodiments, a method for recovering data from an input data stream of a device is disclosed, the method comprising synchronizing, during an initialization phase, a data clock (DCK) with an input data stream; synchronizing, during the initialization phase, an edge clock signal (ECK) with the input data stream based at least in part on a phase relationship between the ECK and the synchronized DCK; and sampling, during the initialization phase, a rising edge of the input data stream with the synchronized ECK to generate a transition level reference voltage. Additional variants and embodiments may also be disclosed and claimed.
摘要:
An echo cancellation circuit includes a variable offset comparator whose input is coupled to receive a transmission line analog signal level. The comparator has a substantially variable offset that is digitally controllable to represent an implied, variable reference level. An output of the comparator provides a value that represents a comparison between the analog transmission line signal level and the implied, variable reference level.
摘要:
A number of comparators are provided where each has a differential input coupled to receive a transmission line analog signal level. Each comparator has substantially variable offset that is controllable to represent a respective variable reference level, without requiring a separate input to receive a voltage reference level. An output of each comparator is to provide a value that represents a comparison between the transmission line analog signal level and the respective reference level.