Periodic calibration for communication channels by drift tracking
DCFirst Claim
1. A method of operation in a system that includes a receive component having circuitry to receive a digital signal, the method comprising:
- subjecting the receive component to a first calibration during initialization to identify an initial value for a parameter affecting proper reception by the circuitry of the receive component of data communicated across a channel as part of the digital signal;
periodically subjecting the receive component to a second calibration to update an existing value of the parameter for drift attributable to change in at least one of operating voltage or temperature; and
wherein the existing value is dependent on the initial value and wherein the second calibration is constrained to occur during a time period that is shorter than a time period of the first calibration.
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Litigations
1 Petition
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.
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Citations
19 Claims
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1. A method of operation in a system that includes a receive component having circuitry to receive a digital signal, the method comprising:
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subjecting the receive component to a first calibration during initialization to identify an initial value for a parameter affecting proper reception by the circuitry of the receive component of data communicated across a channel as part of the digital signal; periodically subjecting the receive component to a second calibration to update an existing value of the parameter for drift attributable to change in at least one of operating voltage or temperature; and wherein the existing value is dependent on the initial value and wherein the second calibration is constrained 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, 9)
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10. A system, comprising:
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a receive component, the receive component having circuitry to receive data communicated across a channel by a transmit component; the receive component to perform at system initialization a first calibration, the first calibration to identify an initial value for a parameter affecting proper reception by the circuitry of the data communicated across the channel, and perform on a periodic basis a second calibration, the second calibration to update an existing value of the parameter for drift attributable to change in at least one of voltage or temperature, wherein a time duration of the second calibration is constrained to be shorter than a time duration of the first calibration; and circuitry to store the existing value of the parameter, the existing value of the parameter dependent on the initial value and any updates from the second calibration. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A system, comprising:
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circuitry to store an existing value representative of at least one of a termination resistance and a driver strength to be applied in association with data communicated across a channel; circuitry to perform a first calibration at system initialization, to identify a first value to be initially applied as the existing value, the first calibration to be performed during a first calibration interval prior to normal system operation; and circuitry to periodically perform a second calibration, to update the existing value; wherein the existing value is initially set and periodically updated responsive to the first calibration and the second calibration, respectively, and wherein the second calibration is constrained to be performed during a time period that is shorter than a time period of the first calibration; and wherein the system further comprises a receive component, the at least one to be applied to permit proper reception of a digital signal to be communicated across a communications channel. - View Dependent Claims (18, 19)
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Specification