Intel Corporation

Tim Frodsham

Sanjay Dabral

Theodore Zale Schoenborn

David Stewart Dunning

Naveen Cherukuri

Aaron T Spink

Jeffrey R Wilcox

Lakshminarayan Krishnamurty

Maurice B Steinman

Rahul R Shah

Phanindra Mannava

Sam E Calvin

David J O'Brien

Muraleedhara Herur Navada

Stephen R Mooney

Allen Jay Baum

Zale Theodore Schoenborn

Michael J Tripp

Tom D Fletcher

Muraleedhara Navada

T Zale Schoenborn

Sanjay Darbal

Robert J Greiner

Nasser A Kurd

David Lawrence Hill

Warren Anderson

Anant S Deval

Javed Sabir Barkatullah

Derek T Bachand

Christopher C Gianos

Santanu Chaudhuri

Suresh Balasubramanian

Eduard Roytman

Mark R Waggoner

Chris D Matthews

Horst W Wagner

Phanindra Mannaya

Chris C Gianos

Richard M Watson

Davis S Dunning

Systems and methods of managing a link provide for receiving a remote width capability during a link initialization, the remote width capability corresponding to a remote port. A link between a local port and the remote port is operated at a plurality of link widths in accordance with the remote width capability.

Dynamically modulating link width

Redundant acknowledgment between agents performing a loopback test over bidirectional communications bus is described. In one example, in a processor including a communications agent coupled to a bidirectional communications bus, the communications agent initiates loopback communications to a second agent, sends a packet including a redundant acknowledgment sequence to the second agent, receives the packet including the redundant acknowledgement sequence looped back from the second agent, determines whether the received redundant acknowledgment sequence is valid, sends a test sequence to the second agent, receives the test sequence looped back, and if the received redundant acknowledgment sequence is determined to be valid, then checks the received test sequence.

Redundant acknowledgment in loopback entry

In one embodiment, the present invention includes a method for writing data from a writer coupled to a reader via an in-die interconnect into a queue entry according to a first clock of the writer, generating a mapping of which second clocks of the reader that the reader is allowed to read from the queue, based at least in part on the first and second clocks, and reading the data from the entry at an allowed second clock. Other embodiments are described and claimed.

Communicating via an in-die interconnect

A technique to perform virtualization of lanes within a common system interface (CSI) link. More particularly, embodiments described herein relate to virtualizing interconnective paths between two or more electronic devices residing in an electronic network.

Technique for lane virtualization

A predetermined network packet is utilized for power reduction in either or both of a transmitter and receiver when information is not needed. Upon detection of the predetermined network packet type, various portions of the transmitter and/or receiver may be clock gated or powered down.

Method, apparatus, and system for idle state definition for power management

Embodiments of the invention provide an algorithm for dividing a link into one or more reduced-width links. For one embodiment of the invention, a multiplexing scheme is employed to effect a bit transmission order required by a particular cyclic redundancy check. The multiplexed output bits are then swizzled on-chip to reduce on-board routing congestion.

Methods and apparatuses to effect a variable-width link

A technique is described by which two link agents with ports coupled together using a point-to-point interconnect in a system exchange their link width support capabilities and negotiate a link width that is mutually agreeable. The interconnect between each pair of agents comprises a pair of uni-directional links having multiple electrical wires, or lanes, where one link is used by a first agent to transmit data to a second agent and another link is used by the second agent to transmit data to the first agent.

Method for identifying bad lanes and exchanging width capabilities of two CSI agents connected across a link

A discussion of improving integrated device deterministic response to test vectors. For example, limiting the transmission delay for an integrated device's response within known bounds by synchronizing an initialization training sequence to a reset deassertion. Specifically, the proposal facilitates response determinism from the DUT by synchronizing training sequences and subsequently synchronizing flit transmission to reset assertion as sampled by reference clock.

Method and system for response determinism by synchronization

A loopback test to test a communication link for a layered interface where in a master agent programs the electrical parameters for the slave agent, such as, the offset, timing, and current compensation with a loopback control register. The slave agent's transmitter and receiver are independently controlled and the master agent may use a slave-echoed data test pattern to detect errors and subsequently sets the appropriate status bits in a loop back status register

Method, system, and apparatus for loopback parameter exchange

A technique for promoting determinism among bus agents within a point-to-point (PtP) network. More particularly, embodiments of the invention relate to techniques to compensate for link latency, data skew, and clock shift within a PtP network of common system interface (CSI) bus agents.

Technique to create link determinism

A method and apparatus for advancing initialization messages when initializing an interface is presented. In one embodiment, one of a sequence of training sequence messages are sent in serial mode across the data lanes of a generally-parallel interface between two agents. When one agent correctly receives a fixed number of messages, it may begin sending its messages with an acknowledgement. Thereafter, when that agent correctly receives a fixed number of messages including an acknowledgement, that agent may advance to sending the next training sequence messages in the sequence.

Method and apparatus for acknowledgement-based handshake mechanism for interactively training links

Redundant acknowledgment between agents performing a loopback test over bidirectional communications bus is described. In one example the acknowledgment is performed by initiating loopback communications from a first agent to a second agent, sending a packet including a redundant acknowledgment sequence from the first agent to the second agent, receiving the packet including the redundant acknowledgement sequence looped back from the second agent at the first agent, sending a test sequence from the first agent to the second agent, and receiving the test sequence looped back from the first agent.

Disclosed are embodiments of a method, apparatus and system for a low power state for a point-to-point link. During the low power state, the signal on both conductors of a differential transmit pair are driven to electrical idle. Analog activity detectors are enabled during the low power state and are disabled during normal power state. Exit from the low power state does not require a physical layer re-initialization sequence. Other embodiments are also described and claimed.

Link power saving state

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Portland, OR, United States of America

Tim Frodsham