Communication channel calibration for drift conditions
First Claim
1. A memory controller integrated circuit (IC), comprising:
- a receiver to sample read data arriving at the memory controller IC from a memory device, the receiver to sample the read data according to a sampling phase defined relative to a sample clock;
logic to establish an initial value of the sampling phase during a calibration operation; and
logic to compensate for drift between the sampling phase and timing associated with the read data transmitted by the memory device, to adjust the initial value in response to drift detected subsequent to establishment of the initial value.
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Accused Products
Abstract
A method and system provides for execution of calibration cycles from time to time during normal operation of the communication channel. A calibration cycle includes de-coupling the normal data source from the transmitter and supplying a calibration pattern in its place. The calibration pattern is received from the communication link using the receiver on the second component. A calibrated value of a parameter of the communication channel is determined in response to the received calibration pattern. The steps involved in calibration cycles can be reordered to account for utilization patterns of the communication channel. For bidirectional links, calibration cycles are executed which include the step of storing received calibration patterns on the second component, and retransmitting such calibration patterns back to the first component for use in adjusting parameters of the channel at first component.
136 Citations
20 Claims
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1. A memory controller integrated circuit (IC), comprising:
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a receiver to sample read data arriving at the memory controller IC from a memory device, the receiver to sample the read data according to a sampling phase defined relative to a sample clock; logic to establish an initial value of the sampling phase during a calibration operation; and logic to compensate for drift between the sampling phase and timing associated with the read data transmitted by the memory device, to adjust the initial value in response to drift detected subsequent to establishment of the initial value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A memory controller integrated circuit (IC), comprising:
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a receiver to sample read data arriving at the memory controller IC from a memory device, the receiver to sample the data according to a sampling phase defined relative to a sample clock; logic to establish an initial value of the sampling phase during a calibration operation; and logic to compensate for drift between the sampling phase and timing associated with the read data transmitted by the memory device, and to adjust the value of the sampling phase in response to drift detected subsequent to establishment of the initial value; wherein the logic to compensate is to obtain test data from the memory device via a communication channel, is to test the test data, and is to incrementally adjust the value of the sampling phase in order to maintain a predetermined phase relationship between the sample clock and the read data transmitted by the memory device. - View Dependent Claims (12, 13, 14, 15)
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16. A memory controller integrated circuit (IC), comprising:
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a receiver to sample read data arriving at the memory controller IC from a memory device according to a sampling phase defined relative to a sample clock; logic to establish an initial value of the sampling phase during a calibration operation; and logic to periodically adjust the value of the sampling phase in order to compensate for drift between the sampling phase and timing associated with the read data transmitted by the memory device; wherein the logic to compensate is to obtain test data from the memory device via a communication channel, is to test the test data, and is to incrementally adjust the value of the sampling phase upward or downward, in order to maintain a desired phase relationship between the sample clock and read data transmitted by the memory device, in a manner adapted to compensate for variation between the sample clock and timing of the read data which is induced by temperature change.
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17. A method of operating a memory controller integrated circuit (IC), comprising:
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sampling read data arriving at the memory controller IC from a memory device according to a sampling phase defined relative to a sample clock; establishing an initial value of the sampling phase during a calibration operation; and adjusting the value of the sampling phase in response to drift between the sampling phase and timing associated with the read data transmitted by the memory device, the drift detected subsequent to establishment of the initial value. - View Dependent Claims (18, 19, 20)
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Specification