摘要:
One embodiment relates to a method of offset cancellation for a receiver in an integrated circuit. The receiver is set to a phase-detector offset-cancellation mode so as to determine offset cancellation settings for the phase detector. The offset cancellation settings are applied to the phase detector. The receiver is then set to a receiver-driver offset-cancellation mode so as to determine an offset cancellation setting for the receiver driver. This offset cancellation setting is applied to the receiver driver. Another embodiment relates to an integrated circuit configured to perform receiver offset cancellation. The integrated circuit including a receiver driver configured to receive a differential input signal, a phase detector including a plurality of latches, a calibration controller, a voltage source, and first and second pairs of switches. Other embodiments, aspects, and features are also disclosed.
摘要:
Automatic rate negotiation logic for a high speed serial interface in a programmable logic device determines whether multiple occurrences of a single-bit transition (i.e., a data transition from “0” to “1” to “0” or from “1” to “0” to “1”) occur within a predetermined time interval on a data channel of a high-speed serial interface. The interval preferably is selected such that multiple occurrences of a single-bit transition mean that the data channel is operating in full-rate mode. The rate negotiation logic may share a phase detector with clock data recovery circuitry in the interface. The phase detector may be a bang-bang phase detector specially adapted to detect single-bit transitions.
摘要:
An integrated circuit (e.g., a programmable integrated circuit such as a programmable microcontroller, a programmable logic device, etc.) includes high-speed serial data signal interface channels, some of which include more circuitry that is dedicated to performing various high-speed serial interface functions than others of those channels have. To increase the flexibility with which such circuitry in a more feature-rich channel can be used, routing is provided for selectively allowing a less feature-rich channel to use certain dedicated circuitry of a more feature-rich channel that is not itself using all of its dedicated circuitry.
摘要:
Automatic rate negotiation logic for a high speed serial interface in a programmable logic device determines whether multiple occurrences of a single-bit transition (i.e., a data transition from “0” to “1” to “0” or from “1” to “0” to “1”) occur within a predetermined time interval on a data channel of a high-speed serial interface. The interval preferably is selected such that multiple occurrences of a single-bit transition mean that the data channel is operating in full-rate mode. The rate negotiation logic may share a phase detector with clock data recovery circuitry in the interface. The phase detector may be a bang-bang phase detector specially adapted to detect single-bit transitions.
摘要:
Integrated circuits with decoupling capacitor circuitry are provided. Decoupling capacitor circuitry may include multiple arrays of decoupling capacitors. Each decoupling capacitor array may have a corresponding decoupling capacitor monitoring circuit that is associated with that decoupling capacitor array. Each decoupling capacitor monitoring circuit may include a resistor and switching circuitry. Each decoupling capacitor monitoring circuit may be coupled to a comparator and control circuitry. During testing, the control circuitry may configure each decoupling capacitor array for leakage current testing one at a time. If a decoupling capacitor array is determined to exhibit excessive leakage currents, that decoupling capacitor array will be marked as defective and will be disabled from use. If the decoupling capacitor array is determined to exhibit tolerable leakage currents, that decoupling capacitor array will be enable for use to help reduce power supply noise.
摘要:
A method, and circuitry, for choosing the correct equalization curve in adaptive equalization uses a feedback loop in which the incoming high-speed serial data are digitized and deserialized for use in the remainder of the device, and also are used by an adaptive state machine to both extract the reference levels for digitization and to control the equalization curve. Detection of the reference level and selection of the equalization curve may be performed at a different rates to avoid interfering with one another. The state machine preferably is programmable. This is useful in any device, but is particularly well-suited for a programmable device, such as a PLD or other programmable integrated circuit device, where conditions may vary according a user logic design.
摘要:
An integrated circuit (e.g., a programmable integrated circuit such as a programmable microcontroller, a programmable logic device, etc.) includes programmable circuitry and a channel of high-speed serial data signal interface (e.g., transceiver) circuitry. To facilitate enabling the integrated circuit to support any of many possible different high-speed serial communication protocols, the channel is hard-wired to include a parallel data bus of fixed width for exchanging parallel data with the programmable circuitry. Regardless of the protocol being implemented, the full width of this bus is always used. A portion of the programmable circuitry is programmed to convert data between the block width and a group width, which can be different from the block width and which is used for the data elsewhere in the integrated circuit.
摘要:
An oscillator circuit includes transistors that are cross-coupled through routing conductors in a first conductive layer. The oscillator circuit also includes a varactor, a capacitor, and an option conductor in a second conductive layer. The option conductor forms at least a portion of a connection between one of the transistors and the capacitor or the varactor.
摘要:
An oscillator circuit includes differential variable delay circuits coupled together to form a ring oscillator. Each of the differential variable delay circuits has first and second inputs and first, second, third, and fourth transistors. A constant supply voltage is provided to sources of the first and the second transistors in each of the differential variable delay circuits. A variable supply voltage is provided to sources of the third and the fourth transistors in each of the differential variable delay circuits. Gates of the first and the third transistors are coupled to the first input. Gates of the second and the fourth transistors are coupled to the second input. The oscillator circuit generates a periodic output signal having a frequency that varies based on changes in the variable supply voltage.
摘要:
An integrated circuit capable of monitoring analog voltages inside an analog block is presented. The integrated circuit has an analog test multiplexer (mux) whose inputs are connected to analog voltages of interest inside an analog block. The analog test multiplexer directs a selected analog voltage from an analog block to the output of the analog test mux. The integrated circuit further includes an analog monitor state machine which provides the selection bits to the analog test multiplexer, enabling random access to the analog voltages inside the analog block. The integrated circuit also includes an analog to digital converter for converting the selected analog voltage from the analog test multiplexer into a digital representation.