DRIFT TRACKING FEEDBACK FOR COMMUNICATION CHANNELS

• US 20100058100A1
• Filed: 11/16/2009
• Published: 03/04/2010
• Est. Priority Date: 03/17/2004
• Status: Active Grant

• Current Assignee: Rambus Inc.
• Original Assignee: Rambus Inc.
• Inventors: Best, Scott C., Lambrecht, Frank, Chang, Kun-Yung, Abhyankar, Abhijit M.
• Granted Patent: US 8,504,863 B2
• Time in Patent Office: Days
• US Class Current: 713/401
• CPC Class Codes: G06F 1/08 Clock generators with changeable or programmable clock frequency
• CPC Class Codes: G06F 1/12 Synchronisation of different clock signals provided by a plurality of clock generators
• CPC Class Codes: G11C 29/02 Detection or location of defective auxiliary circuits, e.g. defective refresh counters
• CPC Class Codes: G11C 29/022 in I/O circuitry
• CPC Class Codes: G11C 29/028 with adaption or trimming of parameters
• CPC Class Codes: G11C 29/50012 of timing
• CPC Class Codes: H04L 25/14 Channel dividing arrangements , i.e. in which a single bit stream is divided between several baseband channels and reassembled at the receiver
• CPC Class Codes: H04L 7/0004 Initialisation of the receiver H04L7/0075 and H04L7/10 take precedence
• CPC Class Codes: H04L 7/0008 Synchronisation information channels, e.g. clock distribution lines
• CPC Class Codes: H04L 7/0033 Correction by delay
• CPC Class Codes: H04L 7/0091 Transmitter details
• CPC Class Codes: H04L 7/033 using the transitions of the received signal to control the phase of the synchronising-signal-generating means, e.g. using a phase-locked loop
• CPC Class Codes: H04L 7/10 Arrangements for initial synchronisation

Abstract

A communication channel includes a first component having a transmitter coupled to a normal signal source, and a second component having a receiver coupled to a normal signal destination. A communication link couples the first and second components. Calibration logic provides for setting an operation value for a parameter of the communication channel, such as by executing an exhaustive calibration sequence at initialization of the link. A tracking circuit, including a monitoring function, tracks drift in the parameter by monitoring a feedback signal that has a characteristic that correlates with drift in the communication channel, and updates, or indicates the need for updating of, the operation value of the parameter in response to the monitoring function.

Claims

1. A communication channel including a first component, a second component, and a communication link coupling the first and second components, the communication channel having a parameter with an operation value, comprising:

means for setting the operation value of the parameter of the communication channel in one of the first and second components;

means for distributing a reference clock signal to the first and second components;

means for monitoring a signal from a medium outside the communication channel, the signal having a characteristic which drifts relative to the reference clock signal by amounts that correlate with drift of the parameter of the communication channel, to track the amounts of drift in the characteristic; and

means, responsive to the means for monitoring, for updating the operation value based on the amounts of drift in the characteristic of the signal.