Abstract:
The present disclosure provides apparatus and methods for the calibration of analog circuitry on an integrated circuit. One embodiment relates to a method of calibrating analog circuitry within an integrated circuit. A microcontroller that is embedded in the integrated circuit is booted up. A reset control signal is sent to reset an analog circuit in the integrated circuit, and a response signal for the analog circuit is monitored by the microcontroller. Based on the response signal, a calibration parameter for the analog circuit is determined, and the analog circuit is 10 configured using the calibration parameter. Other embodiments, aspects and features are also disclosed.
Abstract:
Systems and methods are provided for adjusting gain of a receiver. Adaptation circuitry is operable to identify, based on a matrix representation of a receiver's output generated from horizontal and vertical sweeps of the receiver's output, an eye opening of the receiver's output. The adaptation circuitry is also operable to determine whether a size of the eye opening needs to be changed. When it is determined that the size of the eye opening needs to be changed, the adaptation circuitry is operable to generate a digital signal to change a gain setting of the receiver. When the signal at the receiver's output is under-equalized, the AC gain of the receiver is increased. When the signal at the receiver's output is over-equalized, the AC gain of the receiver is decreased.
Abstract:
A driver circuit drives data to an output based on an input data signal in a transmission mode. The driver circuit includes transistors. A comparator generates a comparison output in a calibration mode based on a reference signal and a signal at the output of the driver circuit. A calibration control circuit adjusts an equivalent resistance of the transistors in the driver circuit based on the comparison output in the calibration mode. The equivalent resistance of the transistors in the driver circuit can be adjusted to support the transmission of data according to multiple different data transmission protocols using transmission links having different characteristic impedances. The equivalent resistance of the transistors in the driver circuit can also be adjusted to compensate for resistance in the package routing conductors and/or to compensate for parasitic resistance.
Abstract:
In one embodiment, an integrated circuit current mirror circuit is disclosed. The integrated circuit current mirror circuit includes a reference circuit, an output circuit and a mode selector circuit. The reference circuit includes an input terminal that receives a reference current. The output circuit generates an output current that is proportional to the reference current. The output circuit is coupled to a load circuit. The output current is provided to the load circuit. The mode selector circuit is coupled to the reference circuit and the output circuit. The mode selector circuit receives a plurality of mode control signals having different voltage levels. The mode selector circuit selects one of the mode control signals. The selected mode control signal is routed to the reference circuit and the output circuit to place the current mirror circuit in a desired mode.
Abstract:
A driver circuit includes unit slice circuits that generate an output data signal based on an input data signal. The driver circuit reduces a voltage swing of the output data signal without changing a termination resistance of the driver circuit in response to decreasing a number of the unit slice circuits that generate the output data signal based on the input data signal.
Abstract:
A circuit includes a phase detector circuit and a data detection circuit. The phase detector circuit generates first and second phase detection signals based on a data signal and a periodic signal. The data detection circuit includes logic circuitry that generates a logic signal based on the first and second phase detection signals. The data detection circuit also includes a plurality of delay elements that generate a series of delayed detection signals based on the logic signal. The data detection circuit generates a data detection signal indicating when the data signal contains data based on the series of delayed detection signals.
Abstract:
Integrated circuits with high-speed communications capabilities are provided. Such types of integrated circuits may include clock data recovery (CDR) circuitry. The CDR circuitry may receive incoming data and may generate multiple clock signals that are used to latch the incoming data. The CDR circuitry may include data latching circuitry for separately latching even and odd data bits in alternating clock cycles. In particular, the data latching circuitry may be controlled using first, second, third, and fourth clock signals having different respective phase settings. The first and second clock signals may be used to capture even and odd data bits, respectively. The third and fourth clock signals may be used to sample data near the transition between the even and odd data bits. The phase of the first and second clock signals may be dynamically adjusted. The phase setting that yields the optimal link performance may be selected for normal operation.
Abstract:
The present disclosure provides a floating-tap decision feedback equalization (DFE) circuit. In an exemplary implementation, the floating-tap DFE circuit may include a high-speed shift register, a deserializer and data selector, a bypass deserializer, a high-speed multiplexer and a tap generation circuit. In one aspect of the invention, the floating-tap DFE circuit may advantageously cover an entire tap range beyond a fixed tap range without holes over a range of data rates. Other embodiments, aspects and features are also disclosed.
Abstract:
Systems and methods are provided for adjusting gain of a receiver. Adaptation circuitry is operable to identify, based on a matrix representation of a receiver's output generated from horizontal and vertical sweeps of the receiver's output, an eye opening of the receiver's output. The adaptation circuitry is also operable to determine whether a size of the eye opening needs to be changed. When it is determined that the size of the eye opening needs to be changed, the adaptation circuitry is operable to generate a digital signal to change a gain setting of the receiver. When the signal at the receiver's output is under-equalized, the AC gain of the receiver is increased. When the signal at the receiver's output is over-equalized, the AC gain of the receiver is decreased.
Abstract:
One embodiment relates to an integrated circuit including multiple PMA modules, a plurality of multiple-purpose PLLs, multiple reference clock signal inputs, and a programmable clock network. Another embodiment relates to a fracture-able PLL circuit. The fracture-able PLL circuit includes a first phase-locked loop circuit generating a first frequency output, a second phase-locked loop circuit; arranged to generate a second frequency output, and a plurality of shared output resources. Reconfigurable circuitry is arranged so that either of the first and second frequency outputs is receivable by each of the plurality of shared output resources. Another embodiment relates to an integrated circuit including a first strip of PLL circuits on a first side of the integrated circuit, and a second strip of PLL circuits on a second side of the integrated circuit which is opposite from the first side. Other embodiments and features are also disclosed.