摘要:
Clock data recovery (CDR) circuitry of a high-speed serial interface on a programmable integrated circuit device toggles, during the electrical idle period of the receiver of the interface, between its “lock-to-reference” (“LTR”) state and its normal “lock-to-data” (“LTD”) state. Whenever during this toggling mode the CDR circuitry toggles to the LTD state, it remains in that state for a predetermined interval and then returns to the LTR state, unless, while it is in the LTD state, it receives a signal from elsewhere in the receiver that data have been received and byte synchronization has occurred. The predetermined toggling interval preferably is long enough to obtain an LTR lock to minimize frequency drift, but short enough to avoid unnecessary delay in detection of the synchronization signal. Preferably, this interval is programmable by the user within limits determined by the characterization of the programmable device. Unreliable analog signal detection is thereby avoided.
摘要:
Clock data recovery (CDR) circuitry of a high-speed serial interface on a programmable integrated circuit device toggles, during the electrical idle period of the receiver of the interface, between its “lock-to-reference” (“LTR”) state and its normal “lock-to-data” (“LTD”) state. Whenever during this toggling mode the CDR circuitry toggles to the LTD state, it remains in that state for a predetermined interval and then returns to the LTR state, unless, while it is in the LTD state, it receives a signal from elsewhere in the receiver that data have been received and byte synchronization has occurred. The predetermined toggling interval preferably is long enough to obtain an LTR lock to minimize frequency drift, but short enough to avoid unnecessary delay in detection of the synchronization signal. Preferably, this interval is programmable by the user within limits determined by the characterization of the programmable device. Unreliable analog signal detection is thereby avoided.
摘要:
A programmable logic integrated circuit device (“PLD”) includes high-speed serial interface (“HSSI”) circuitry that is at least partly hard-wired to perform at least some functional aspects of the HSSI operations. Cyclic redundancy check (CRC) generation and/or checking circuitry is now included in this HSSI circuitry, and again, this CRC circuitry is at least partly hard-wired to perform at least some functional aspects of its operations(s).
摘要:
Embodiments include a configurable multi-protocol transceiver including configurable deskew circuitry. In one embodiment, configurable circuitry is adapted to control an allowed data depth of a plurality of buffers. In another embodiment, configurable circuitry is adapted to control a deskew character transmit insertion frequency. In another embodiment, a programmable state machine is adapted to control read and write pointers in accordance with selectable conditions for achieving an alignment lock condition. In another embodiment, configurable circuitry is adaptable to select between logic and routing resources in the transceiver and logic and routing resources in a core of the IC in which the transceiver is implemented for controlling at least certain deskew operations. In another embodiment, configurable selection circuitry allows deskew processing to occur in a data path either before or after clock compensation processing depending on a communication protocol for which the transceiver is to be configured.
摘要:
A method and system for operating a communication circuit during periods of reduced energy consumption are disclosed. Data may be transmitted over a communication link from a first device to a second device in a low-power state. The data may be used by the second device to update coefficients and/or synchronize the receiver of the second device to a transmitter of the first device, thereby enabling a more efficient or rapid transition from the low-power state to an active state. A transmitter of the first device and a receiver of the second device may be activated before transmission of the data and deactivated after transmission of the data. In this manner, a receiver of the second device may be refreshed to enable a more efficient transition from the low-power state to an active state.
摘要:
On programmable device, each layer of a programmable interface, for a protocol which has a protocol stack including at least a physical layer, a data link layer and a transaction layer, is selectably bypassable. When a layer is bypassed, all other layers downstream of that layer also are bypassed. In addition, the interface may be divided into different clock domains running at different clock rates, reflecting clock rates within the programmable device and outside the programmable device. Layers may be bypassed to allow a user to substitute a custom layer in programmable logic, or to substitute an updated layer for debugging purposes.
摘要:
Embodiments in the disclosure include a multi-protocol transceiver including a configurable arrangement of receive and/or transmit circuitry. An exemplary transceiver can be selectively configured to effectively transmit and/or receive data communications corresponding to a select one of a plurality of high-speed communication protocols. Another more particular embodiment disclosed includes a configurable data path through link-wide Physical Coding Sub-layer (“PCS”) circuitry including link-wide clock compensation, encoding/decoding, and scrambling/descrambling circuitry and lane striping/de-striping circuitry; the configurable data path further includes lane-wide circuitry including clock compensation, encoding/decoding, receive block sync, and Physical Medium Access sub-layer (“PMA”) circuitry, and further includes bit muxing/de-muxing circuitry coupled to Physical Medium Dependent (“PMD”) sub-layer circuitry.
摘要:
A configurable interface includes a transmitter module and a receiver module, each configured to operate according to at least three different interface standards. The configurable interface further includes an interface module configured to determine a physical medium attachment (PMA) standard of a PMA coupled to the configurable interface and activate at least one component of the configurable interface based on the PMA standard. In an arrangement, the device interface supports a CAUI-4 standard.
摘要:
A method and system for transitioning a communication circuit to a low-power state are disclosed. Where a first device and a second device communicate over a communication link, the first device may initiate a transition from an active state to a low-power state to conserve energy. A symbol may be encoded by the first device in data and transmitted to the second device. The first device may deactivate one or more components when entering the low-power state. Additionally, responsive to receiving and decoding the symbol, the second device may deactivate one or more components when entering the low-power state. In this manner, energy consumption of one or more components can be reduced and a low-power state may be entered to conserve energy.
摘要:
One embodiment relates to an integrated circuit configured to perform dynamic transmit equalization of a bi-directional lane. The integrated circuit including an interface between the physical coding and media access control circuitry, and an equalization control circuit which is external to the physical coding circuitry and which is configured to perform the dynamic transmit equalization using said interface. Another embodiment relates to a transceiver circuit which includes physical coding circuitry and media access control circuitry. The transceiver circuit further includes an interface between the physical coding circuitry and the media access control circuitry and an equalization controller which is external to the physical coding circuitry and which is configured to perform dynamic transmit equalization using said interface. The interface is configured to provide transmit coefficient data in a time-multiplexed signal format from the media access control circuitry to the physical coding circuitry. Other embodiments, aspects, and features are also disclosed.