Periodic calibration for communication channels by drift tracking
First Claim
1. A method of operation as carried out by a component, the method comprising:
- performing a first calibration during initialization of the component, the first calibration to identify an initial value for a parameter pertaining to at least driver strength and termination resistance; and
periodically performing second calibrations to update the value for the parameter, the value being updated for drift attributable to change in at least one of operating voltage or temperature, wherein the second calibrations are each to occur during a time period that is shorter than a time period of the first calibration.
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Accused Products
Abstract
A method and system that provides for execution of a first calibration sequence, such as upon initialization of a system, to establish an operation value, which utilizes an algorithm intended to be exhaustive, and executing a second calibration sequence from time to time, to measure drift in the parameter, and to update the operation value in response to the measured drift. The second calibration sequence utilizes less resources of the communication channel than does the first calibration sequence. In one embodiment, the first calibration sequence for measurement and convergence on the operation value utilizes long calibration patterns, such as codes that are greater than 30 bytes, or pseudorandom bit sequences having lengths of 2N−1 bits, where N is equal to or greater than 7, while the second calibration sequence utilizes short calibration patterns, such as fixed codes less than 16 bytes, and for example as short as 2 bytes long.
136 Citations
20 Claims
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1. A method of operation as carried out by a component, the method comprising:
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performing a first calibration during initialization of the component, the first calibration to identify an initial value for a parameter pertaining to at least driver strength and termination resistance; and periodically performing second calibrations to update the value for the parameter, the value being updated for drift attributable to change in at least one of operating voltage or temperature, wherein the second calibrations are each to occur during a time period that is shorter than a time period of the first calibration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A component comprising:
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a transmitter circuit having a driver to output data onto a communication link, the driver having a driver strength setting; circuitry to store a value representative of at least one of a termination resistance and the driver strength setting; and circuitry to perform calibration, the calibration including a first calibration at system initialization, to establish the value during a first calibration interval that occurs prior to normal system operation, and during the normal system operation, to perform second calibrations to update the value, wherein the second calibrations are each performed during a second calibration interval that is shorter than the first calibration interval. - View Dependent Claims (10, 11, 12, 13, 14)
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15. A component comprising:
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a transmitter circuit to output data onto the communication link in accordance with a plurality of parameters; and circuitry to perform calibration including a first calibration at system initialization, to establish initial values for the plurality of parameters during a first calibration interval that occurs prior to normal system operation, and the circuitry to perform calibration to perform a second calibration during the normal system operation, the second calibration to update the initial values for the plurality of parameters during the normal system operation, wherein the second calibration is performed during a second calibration interval that is shorter than the first calibration interval. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification