Advanced Micro Devices Corporation

Ati Technologies Ulc

Damon Tohidi

Gerald Robert Talbot

Michael J Tresidder

Edoardo Prete

Milam Paraschou

Hanwoo Cho

Jeffrey Cooper

Stanley Ames Lackey, Jr

Varun Gupta

Thomas H Likens, Iii

Chad S Gallun

Eric Ian Carpenter

Gurunath Dollin

Scott F Dow

Shalini Sodagam

Anandh Ganesan

Nandeesh Thimmappa

Stanley Lackey

Systems, apparatuses, and methods for utilizing training sequences on a replica lane are described. A transmitter is coupled to a receiver via a communication channel with a plurality of lanes. One of the lanes is a replica lane used for tracking the drift in the optimal sampling point due to temperature variations, power supply variations, or other factors. While data is sent on the data lanes, test patterns are sent on the replica lane to determine if the optimal sampling point for the replica lane has drifted since a previous test. If the optimal sampling point has drifted for the replica lane, adjustments are made to the sampling point of the replica lane and to the sampling points of the data lanes.

Channel training using a replica lane

Systems, apparatuses, and methods for implementing a deskewing method for a physical layer interface on a multi-chip module are disclosed. A circuit connected to a plurality of communication lanes trains each lane to synchronize a local clock of the lane with a corresponding global clock at a beginning of a timing window. Next, the circuit symbol rotates each lane by a single step responsive to determining that all of the plurality of lanes have an incorrect symbol alignment. Responsive to determining that some but not all of the plurality of lanes have a correct symbol alignment, the circuit symbol rotates lanes which have an incorrect symbol alignment by a single step. When the end of the timing window has been reached, the circuit symbol rotates lanes which have a correct symbol alignment and adjusts a phase of a corresponding global clock to compensate for missed symbol rotations.

Deskewing method for a physical layer interface on a multi-chip module

An indeterminate state representative of a metastable state is inserted into an output signal of a circuit representation responsive to the circuit representation receiving a metastable triggering event during a register transfer language (RTL) simulation. The simulation view of the RTL has been modified to ensure that the indeterminate state is propagated through the circuit representations regardless of the input on which the indeterminate state appears. The indeterminate state is maintained for a programmable amount of time and responsive to expiration of the amount of time, the output signal is set to a random binary value.

Metastability insertion using the X-state

Systems, apparatuses, and methods for implementing asynchronous feedback training sequences are described. A transmitter transmits a training sequence indication to a receiver via a communication channel including a plurality of data lines. The training sequence indication includes a bit sequence to indicate the beginning of a training sequence. The indication includes a transition from a zero to a one at the midpoint of a supercycle of 'N' clock cycles in length, followed by a predetermined number of ones. The training sequence indication is then followed by a test pattern. The beginning of the test pattern occurs at the end of a supercycle. The receiver determines if there are any errors in the received test pattern, and then sends feedback to the transmitter that indicates whether any errors were detected. Responsive to receiving the feedback, the transmitter alters delay settings for one or more of the data lines.

Asynchronous feedback training

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Richmond Hill, Canada

Damon Tohidi