Periodic calibration for communication channels by drift tracking
First Claim
1. In a memory system, in which a memory controller and a memory device communicate data across a channel, and in which channel timing is periodically calibrated, a method comprising:
- performing, using at least one of the memory controller and the memory device, a first calibration operation associated with communication across the channel to identify an initial value for a data eye timing point;
periodically performing, using at least one of the memory controller and the memory device, drift tracking using a second calibration operation, including identifying drift associated with the data eye timing point location; and
in response to drift tracking, updating the data eye timing point, and communicating data across the channel using the data eye timing point as updated.
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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.
106 Citations
35 Claims
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1. In a memory system, in which a memory controller and a memory device communicate data across a channel, and in which channel timing is periodically calibrated, a method comprising:
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performing, using at least one of the memory controller and the memory device, a first calibration operation associated with communication across the channel to identify an initial value for a data eye timing point; periodically performing, using at least one of the memory controller and the memory device, drift tracking using a second calibration operation, including identifying drift associated with the data eye timing point location; and in response to drift tracking, updating the data eye timing point, and communicating data across the channel using the data eye timing point as updated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of data eye calibration associated with a data signal, comprising:
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performing a first calibration operation in which a relatively long calibration pattern is employed to find an initial position of each of two opposing data eye edges, to thereby determine at least one of height or width of the data eye; periodically performing a second calibration operation that uses a starting position based upon a previous position of at least one of the opposing edges, and that tests for drift in relation to the previous position, the second calibration operation producing an offset from the originally determined height or width; and updating a reference used to sample the data signal, the reference based upon a result of the first calibration operation as incremented or decremented by at least one offset resulting from performance of the second calibration operation. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. An integrated circuit device, comprising:
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transmitter circuitry adapted to perform a first calibration operation associated with communication across a channel to identify an initial value for a data eye timing point, and a second calibration operation to perform drift tracking using the data eye timing point, the second calibration operation identifying drift associated with the data eye timing point; and adjustment circuitry to update, in response to drift tracking, the data eye timing point, where the channel has a plurality of links, and where the adjustment circuitry is adapted to communicate data over a plurality of links using a timing point updated for each one of the plural links. - View Dependent Claims (20, 21)
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22. An integrated circuit device, comprising:
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transmitter circuitry adapted to perform a first calibration operation associated with communication across a channel to identify an initial value for a data eye timing point, and a second calibration operation to perform drift tracking using the data eye timing point, the second calibration operation identifying drift associated with the data eye timing point; and adjustment circuitry to update, in response to drift tracking, the data eye timing point, where the first calibration operation uses a long calibration sequence to find the vertical edges of a data eye, and the second calibration operation uses a short calibration sequence adapted to adjust the use of test patterns to coincide with the location of at least one vertical edge of a data eye, and use the test patterns to test for change in the location, and the adjustment circuitry updates a data eye sampling point based upon change in the location of the at least one vertical edge. - View Dependent Claims (23)
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24. An integrated circuit device, comprising:
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transmitter circuitry adapted to perform a first calibration operation associated with communication across a channel to identify an initial value for a data eye timing point, and a second calibration operation to perform drift tracking using the data eye timing point, the second calibration operation identifying drift associated with the data eye timing point; and adjustment circuitry to update, in response to drift tracking, the data eye timing point, where each of the first calibration operation and the second calibration operation is performed with results communicated back to the device on a side-band link, and the transmitter circuitry is adapted to communicate information to a receiver to phase-adjust a sampling signal based upon the drift tracking.
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25. An integrated circuit device, comprising:
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transmitter circuitry adapted to perform a first calibration operation associated with communication across a channel to identify an initial value for a data eye timing point, and a second calibration operation to perform drift tracking using the date eye timing point, the second calibration operation identifying drift associated with the data eye timing point; and adjustment circuitry to update, in response to drift tracking, the data eye timing point, where the timing point location is a data eye edge, and where the data eye timing point is a data eye sampling point.
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26. An integrated circuit device, comprising:
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transmitter circuitry adapted to perform a first calibration operation associated with communication across a channel to identify an initial value for a data eye timing point, and a second calibration operation to perform drift tracking using the data eye timing point, the second calibration operation identifying drift associated with the data eye timing point; and adjustment circuitry to update, in response to drift tracking, the data eye timing point, where the transmitter circuitry is adapted to perform the first calibration operation and the second calibration operation, and where the adjustment circuitry is adapted to update the data eye timing point on a common link of the channel, and to update a sampling point for data transmitted over the common link.
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27. An integrated circuit device, comprising:
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transmitter circuitry adapted to perform a first calibration operation associated with communication across a channel to identify an initial value for a data eye timing point, and a second calibration operation to perform drift tracking using the date eye timing point, the second calibration operation identifying drift associated with the date eye timing point; and adjustment circuitry to update, in response to drift tracking, the data eye timing point, where the transmitter circuitry is adapted to perform the first calibration operation and the second calibration operation, each on one link, and the adjustment circuitry is adapted to responsively update the data eye timing point for a plurality of links of the channel.
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28. A device adapted to perform data eye calibration associated with a data signal, comprising:
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transmitter circuitry adapted to perform a first calibration operation in which a relatively long calibration pattern is employed to find an initial value for each of two opposing data eye edges, to thereby determine at least one of height or width of the data eye, and adapted to periodically perform a second calibration operation that uses a starting position based upon the date eye timing point at least one of the opposing edges, and that tests for drift in relation to the date eye timing point, the second calibration operation producing an offset from the originally determined height or width; and adjustment circuitry adapted to update a reference used to sample the data signal, the reference based upon a result of the first calibration operation as incremented or decremented by at least one offset resulting from performance of the second calibration operation. - View Dependent Claims (29, 30, 31, 32, 33, 34)
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35. An integrated circuit device, comprising:
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transmitter circuitry adapted to perform a first calibration operation associated with communication across a channel to identify an initial value for data eye timing point, and a second calibration operation to perform drift tracking using the data eye timing point, the second calibration operation identifying drift associated with the data eye timing point; and adjustment circuitry to update, in response to drift tracking, the data eye timing point.
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Specification