摘要:
High-speed serial interface or transceiver circuitry on a programmable logic device integrated circuit (“PLD”) includes features that permit the PLD to satisfy a wide range of possible user needs or applications. This range includes both high-performance applications and applications in which reduced power consumption by the PLD is important. In the latter case, any one or more of various features can be used to help reduce power consumption.
摘要:
In high speed receiver circuitry (e.g., on a programmable logic device (PLD) or the like), decision feedback equalization (DFE) circuitry is used to at least partly cancel unwanted offset (e.g., from other elements of the receiver). The data input to the receiver is tristated; and then each DFE tap coefficient is varied in turn to find coefficient values that are associated with transitions between oscillation and non-oscillation of the receiver output signal. The coefficient values found in this way are used to select trial values. If the output signal of the receiver does not oscillate when these trial values are used, the process is repeated starting from these (or subsequent) trial values until a final set of trial values does allow oscillation of the receiver output signal.
摘要:
High-speed serial interface or transceiver circuitry on a programmable logic device integrated circuit (“PLD”) includes features that permit the PLD to satisfy a wide range of possible user needs or applications. This range includes both high-performance applications and applications in which reduced power consumption by the PLD is important. In the latter case, any one or more of various features can be used to help reduce power consumption.
摘要:
One embodiment relates to an integrated circuit including a first strip of phase-locked loop (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. The PLL circuits in the first and second strips may be configured by programming the integrated circuit. Another embodiment relates to an integrated circuit including a plurality of phase-locked loop (PLL) circuits and a plurality of physical media attachment (PMA) triplet modules adjacent to the plurality of PLL circuits. Each PMA triplet module includes first, second and third channels. The first and third channels are arranged for use as receiving channels, and the second channel is arranged to be configurable as either a receiving channel or a clock multiplication unit. Other embodiments and features are also disclosed.
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:
A circuit includes a first area, a second area, and a third area. The second area includes a locked loop circuit that generates a clock signal. The locked loop circuit receives a supply voltage that is isolated from noise generated in the first area. The third area includes multiple quads of channels and a clock line coupled to route at least one clock signal generated in the second area to the channels in each of the quads. The third area is separate from the second area in the circuit.
摘要:
High-speed serial interface or transceiver circuitry on a programmable logic device integrated circuit (“PLD”) includes features that permit the PLD to satisfy a wide range of possible user needs or applications. This range includes both high-performance applications and applications in which reduced power consumption by the PLD is important. In the latter case, any one or more of various features can be used to help reduce power consumption.
摘要:
The architecture of a programmable logic device (“PLD”) is modified in one or more of several respects to facilitate inclusion of high-speed serial interface (“HSSI”) circuitry in the PLD. For example, the HSSI circuitry is preferably located along one side of the device, taking the place of regular peripheral IO circuitry in that area. Certain portions of the core logic circuitry are modified to better interface with the HSSI circuitry.
摘要:
Equalization of an incoming data signal can be controlled by sampling that signal at times when data values in that signal should be stable (“data samples”) and when that signal should be in transition between successive data values that are different (“transition samples”). A transition sample that has been taken between two successive differently valued data samples is compared to a reference value (which can be one of those two data samples). The result of this comparison can be used as part of a determination as to whether to increase or decrease equalization of the incoming data signal.