Abstract: A flit-based packetization approach is used for transmitting information between electronic components. A protocol stack can generate transaction layer packets from information received from a transmitting device, assemble the transaction layer packets into one or more flits, and protect the flits with a flit-level cyclic redundancy check (CRC) scheme and a flit-level forward error correction or parallel-forward error correction (FEC) scheme. Flit-level FEC schemes can provide improved latencies and efficiencies over per-lane FEC schemes. To improve retry probability, flits can contain information indicating whether immediately preceding flits are null flits. Receivers can avoid sending a retry request for a corrupted flit if a seceding flit indicates the corrupted flit is a null fit. Parity flits can be used to protect groups of flits and correct single-flit errors.

Abstract: A system and apparatus can include a first port configured to support a first link width; a second port configured to support a second link width, the second link width different from the first link width; and physical layer logic to receive from the first port a first data block arranged according to the first link width and frequency; create at least one second data block arranged according the second link width and frequency, the at least one second data block including data bytes from the first data block arranged sequentially in the at least one second data block; and transmit the at least one second data block to the second port.

Abstract: Methods and apparatuses associated with a secure stream protocol for a serial interconnect are disclosed herein. In embodiments, an apparatus comprises a transmitter and a receiver. The transmitter and receiver are configured to transmit and receive transaction layer data packets through a link, the transaction layer data packets including indicators associated with transmission of order set transmitted after a predetermined number of data blocks, when the transmission is during a header suppression mode. Additional features and other embodiments are also disclosed.

Abstract: A device includes a port with a replay buffer and protocol logic to receive a flit in a sequence of flits to be sent on a point-to-point link and determine an error in the flit. Based on the error, a copy of the flit is stored in a first position within the replay buffer as well as a copy of a next flit received in the sequence of flits, which is stored in a second position within the replay buffer. The copies of the flits are then written to a register for access by software.

Abstract: Systems, methods, and devices can involve a host device that includes a root complex, a link, and an interconnect protocol stack coupled to a bus link. The interconnect protocol stack can include multiplexing logic to select one of a Peripheral Component Interconnect Express (PCIe) upper layer mode, or an accelerator link protocol upper layer mode, the PCIe upper layer mode or the accelerator link protocol upper layer mode to communicate over the link, and physical layer logic to determine one or more low latency features associated with one or both of the PCIe upper layer mode or the accelerator link protocol upper layer mode.

Abstract: A shared memory controller is to service load and store operations received, over data links, from a plurality of independent nodes to provide access to a shared memory resource. Each of the plurality of independent nodes is to be permitted to access a respective portion of the shared memory resource. Interconnect protocol data and memory access protocol data are sent on the data links and transitions between the interconnect protocol data and memory access protocol data can be defined and identified.

Abstract: A device includes physical layer (PHY) circuitry including a physical coding sublayer, where the PHY circuitry is configured to alternatively support at least two different power control settings. The device further includes an interface to couple the PHY circuitry to a media access control (MAC) layer, where the interface comprises a set of data pins, a set of command pins, a set of status pins, one or more clock pins, and a plurality of power control pins to receive an indication of a particular one of the at least two power control settings. The PHY circuitry is to apply parameters corresponding to the particular control setting during operation based on the indication.

Abstract: Systems and devices can include a first port of a first device coupled to a second port of a second device across a multi-lane link. The first port can augment a data block with error correcting code by distributing error correcting code evenly across each lane of the data block, wherein each lane of the data block includes a same number of error correcting code. The first port can transmit the data block with the per-lane error correcting code to the second port across the multi-lane link. The second port can determine error correcting code based on the error correcting code bits received in the data block, and perform error correction on the symbols of the data block based on the error correcting code received.

Abstract: Systems, methods, and computer-readable media are disclosed for an apparatus coupled to a communication bus, where the apparatus includes a queue and a controller to manage operations of the queue. The queue includes a first space to store a first information for a first traffic type, with a first flow class, and for a first virtual channel of communication between a first communicating entity and a second communicating entity. The queue further includes a second space to store a second information for a second traffic type, with a second flow class, and for a second virtual channel of communication between a third communicating entity and a fourth communicating entity. The first traffic type is different from the second traffic type, the first flow class is different from the second flow class, or the first virtual channel is different from the second virtual channel. Other embodiments may be described and/or claimed.

Abstract: Embodiments may be generally direct to apparatuses, systems, method, and techniques to provide multi-interconnect protocol communication. In an embodiment, an apparatus for providing multi-interconnect protocol communication may include a component comprising at least one connector operative to connect the component to at least one off-package device via a standard interconnect protocol, and logic, at least a portion of the logic comprised in hardware, the logic to determine data to be communicated via a multi-interconnect protocol, provide the data to a multi-protocol multiplexer to determine a route for the data, route the data on-package responsive to the multi-protocol multiplexer indicating a multi-interconnect on-package mode, and route the data off-package via the at least one connector responsive to the multi-protocol multiplexer indicating a multi-interconnect off-package mode. Other embodiments are described.

Abstract: A system and apparatus can include a port for transmitting data; and a link coupled to the port. The port can include a physical layer device (PHY) to decode a physical layer packet, the physical layer packet received across the link. The physical layer packet can include a first bit sequence corresponding to a first ordered set, and a second bit sequence corresponding to a second ordered set, the first bit sequence immediately adjacent to the second bit sequence. The first ordered set is received at a predetermined ordered set interval, which can occur following a flow control unit (flit). The first ordered set comprises eight bytes and the second ordered set comprises eight bytes. In embodiments, bit errors in the ordered sets can be determined by checking bits received against expected bits for the ordered set interval.

Abstract: In embodiments, an apparatus for serial communication includes a transceiver, to receive a precoding request from a downlink receiver across a serial communication link, and to transmit data bits to the downlink receiver over the serial communication link. In embodiments, the apparatus further includes a precoder, coupled to the transceiver, to: receive scrambled data bits of a subset of the data bits to be transmitted, from a coupled scrambler, and, in response to the request from the downlink receiver, precode the scrambled data bits, and output the precoded scrambled data bits to the transceiver, for transmission to the downlink receiver across the serial communication link together with other unscrambled data bits.

Abstract: In one embodiment, an apparatus includes PHY circuitry to implement a PHY-based retry technique, e.g., in die-to-die interfaces. The PHY circuitry includes a retry buffer to buffer data provided by the interface controller and error detection code generation circuitry to generate error detection codes based on input data. The PHY circuitry is to implement the retry technique by detecting a stall signal asserted by another apparatus across the channel, causing the error detection code generation circuitry to generate error detection codes based on data in the retry buffer, and transmitting the data from the retry buffer and its corresponding error detection codes across the channel to the other apparatus.

Abstract: Aspects of the embodiments are directed to systems and methods for performing link training using stored and retrieved equalization parameters obtained from a previous equalization procedure. As part of a link training sequence, links interconnecting an upstream port with a downstream port and with any intervening retimers, can undergo an equalization procedure. The equalization parameter values from each system component, including the upstream port, downstream port, and retimer(s) can be stored in a nonvolatile memory. During a subsequent link training process, the equalization parameter values stored in the nonvolatile memory can be written to registers associated with the upstream port, downstream port, and retimer(s) to be used to operate the interconnecting links. The equalization parameter values can be used instead of performing a new equalization procedure or can be used as a starting point to reduce latency associated with equalization procedures.

Abstract: An apparatus is provided that includes a set of registers, and an interface of a computing block. The computing block includes one of a physical layer block or a media access control layer block. The interface includes one or more pins to transmit asynchronous signals, one or more pins to receive asynchronous signals, and a set of pins to communicate particular signals to access the set of registers, where a set of control and status signals of a defined interface are mapped to respective bits of the set of registers.

Abstract: There is disclosed in an example an interconnect apparatus having: a root circuit; and a downstream circuit comprising at least one receiver; wherein the root circuit is operable to provide a margin test directive to the downstream circuit during a normal operating state; and the downstream circuit is operable to perform a margin test and provide a result report of the margin test to the root circuit. This may be performed in-band, for example in the L0 state. There is also disclosed a system comprising such an interconnect, and a method of performing margin testing.

Abstract: Aspects of the embodiments are directed to systems, methods, and devices that can activate forward error correction (FEC) based on the channel loss of a channel. The channel's loss can be characterized as a high loss channel if the channel loss exceeds a predetermined threshold value. For channels with high loss and for those that operate at high data rates (e.g., data rates commensurate with PCIe Gen 4 or Gen 5), FEC can be activated so that the channels can achieve higher data rates.

Abstract: Systems, methods, and devices can involve a host device that includes a root complex, a link, and an interconnect protocol stack coupled to a bus link. The interconnect protocol stack can include multiplexing logic to select one of a Peripheral Component Interconnect Express (PCIe) upper layer mode, or an accelerator link protocol upper layer mode, the PCIe upper layer mode or the accelerator link protocol upper layer mode to communicate over the link, and physical layer logic to determine one or more low latency features associated with one or both of the PCIe upper layer mode or the accelerator link protocol upper layer mode.

Abstract: The present disclosure describes a number of embodiments related to devices and techniques for implementing an interconnect switch to provide a switchable low-latency bypass between node resources such as CPUs and accelerator resources for caching. A resource manager may be used to receive an indication of a node of a plurality of nodes and an indication of an accelerator resource of a plurality of accelerator resources to connect to the node. If the indicated accelerator resource is connected to another node of the plurality of nodes, then transmit, to a interconnect switch, one or more hot-remove commands. The resource manager may then transmit to the interconnect switch one or more hot-add commands to connect the node resource and the accelerator resource.

Abstract: An apparatus may comprise multiplexing circuitry to select an ingress lane from among a plurality of ingress lanes to couple to an egress lane; and retiming circuitry to retime a signal received on the selected ingress lane and transmit the retimed signal on the egress lane.