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 10 Gigabit Ethernet (10 GbE) transceiver circuitry. The programmable circuitry and the transceiver circuitry may be configured to implement the physical (PHY) layer of the 10 GbE networking specification. This integrated circuit may then be coupled to an optical transceiver module in order to transmit and receive 10 GbE optical signals. The transceiver circuitry and interface circuitry that connects the transceiver circuitry with the programmable circuitry may be hard-wired or partially hard-wired.
摘要:
A transmitter that includes a first phase locked loop (PLL) and a second PLL coupled to the first PLL is described. In one implementation, the first PLL is an inductance-capacitance (LC) type PLL and the second PLL is a ring type PLL. Also, in one embodiment, the transmitter further includes a PLL selection multiplexer coupled to the first and second PLLs, where the PLL selection multiplexer receives an output of the first PLL and an output of the second PLL and outputs either the output of the first PLL or the output of the second PLL. In one implementation, a control signal for controlling selection by the PLL selection multiplexer is programmable at runtime. In one implementation, the transmitter of the present invention further includes a clock generation block coupled to the PLL selection multiplexer, a serializer block coupled to the clock generation block and a transmit driver block coupled to the serializer block. In one embodiment, the transmit driver block includes only one post-tap pre-driver and only one main-tap pre-driver. The transmitter of the present invention is capable of operating in a wide range mode or a low jitter mode by selecting the appropriate PLL. In wide range mode, a wider frequency range is desirable. On the other hand, in low jitter mode, a low jitter is desirable.
摘要:
Signal detection circuitry for a serial interface oversamples the input—i.e., samples the input multiple times per clock cycle—so that the likelihood of missing a signal is reduced. Sampling may be done with a regenerative latch which has a large bandwidth and can latch a signal at high speed. The amplitude threshold for detection may be programmable, particularly in a programmable device. Thus, between the use of a regenerative latch which is likely to catch any signal that might be present, and the use of oversampling to avoid the problem of sampling at the wrong time, the likelihood of failing to detect a signal is greatly diminished. Logic, such as a state machine, may be used to determine whether the samples captured s do or do not represent a signal. That logic may be programmable, allowing a user to set various parameters for signal detection.
摘要:
Transmitter driver circuitry for outputting a high-speed serial data signal (e.g., in the range of about 10 gigabits per second or higher) includes H-tree driver circuitry having only a main driver stage and a post-tap driver stage. At least one transistor in the H-tree driver circuitry is constructed and connected to provide electrostatic discharge protection. PMOS and NMOS current sources are used for the H-tree driver circuitry to enhance power supply noise rejection.
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 10 Gigabit Ethernet (10 GbE) transceiver circuitry. The programmable circuitry and the transceiver circuitry may be configured to implement the physical (PHY) layer of the 10GbE networking specification. This integrated circuit may then be coupled to an optical transceiver module in order to transmit and receive 10 GbE optical signals. The transceiver circuitry and interface circuitry that connects the transceiver circuitry with the programmable circuitry may be hard-wired or partially hard-wired.
摘要:
High-speed serial data signal transmitter and/or receiver circuitry is able to dynamically switch between handling data at two (or more) different data rates. Such a switch can be made very rapidly and with no requirement for reprogramming or reconfiguring the circuitry. Circuitry for glitchlessly switching between clock signals having different frequencies is also provided and may be used in the above-mentioned transmitter and/or receiver circuitry.
摘要:
Signal detection circuitry for a serial interface oversamples the input—i.e., samples the input multiple times per clock cycle—so that the likelihood of missing a signal is reduced. Sampling may be done with a regenerative latch which has a large bandwidth and can latch a signal at high speed. The amplitude threshold for detection may be programmable, particularly in a programmable device. Thus, between the use of a regenerative latch which is likely to catch any signal that might be present, and the use of oversampling to avoid the problem of sampling at the wrong time, the likelihood of failing to detect a signal is greatly diminished. Logic, such as a state machine, may be used to determine whether the samples captured s do or do not represent a signal. That logic may be programmable, allowing a user to set various parameters for signal detection.
摘要:
Integrated circuits with phase-locked loops are provided. Phase-locked loops may include an oscillator, a phase-frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator, and a programmable divider. The voltage-controlled oscillator may include multiple inductors, an oscillator circuit, and a buffer circuit. A selected one of the multiple inductors may be actively connected to the oscillator circuit. The voltage-controlled oscillators may have multiple oscillator circuits. Each oscillator circuit may be connected to a respective inductor, may include a varactor, and may be powered by a respective voltage regulator. Each oscillator circuit may be coupled to a respective input transistor pair in the buffer circuit through associated coupling capacitors. A selected one of the oscillator circuits may be turned on during normal operation by supplying a high voltage to the selected one of the oscillator circuit and by supply a ground voltage to the remaining oscillator circuits.
摘要:
A loss-of-signal detector includes digital and analog monitoring of incoming data. The incoming signal is compared digitally to at least one predetermined pattern that may indicate a loss of signal, and also is monitored by an analog detector that detects transitions in the data. If the digital comparison fails to match any of the at least one predetermined pattern, or if transitions are detected by the analog monitoring, even if the digital comparison produces a pattern match, then loss of signal is not indicated.
摘要:
An integrated circuit device such as a programmable logic device (“PLD”) includes a plurality of blocks of legacy circuitry. These legacy blocks leave at least one corner of the device unoccupied by such legacy circuitry. This at least one corner is used for relatively newly developed circuitry so as to simplify and speed the design of relatively new circuitry, to avoid having to significantly redesign any of the legacy circuitry to give the device the capabilities of the new circuitry, etc. The relatively newly developed circuitry may be high-speed serial data signal interface (“HSSI”) circuitry that is capable of operating at serial data rates faster than any legacy HSSI circuitry on the device.