Memory controller that calibrates a transmit timing offset
First Claim
1. A memory controller to control a memory device, the memory controller comprising:
- a transmitter to output a calibration sequence to the memory device;
a receiver to receive a signal representing a phase difference between a clock signal received at the memory device and the calibration sequence as received by the memory device; and
,circuitry to apply a transmit timing offset to write data, based on the phase difference between the clock signal as received at the memory device and the calibration sequence as received by the memory device.
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Accused Products
Abstract
An integrated circuit device includes a transmitter circuit operable to transmit a timing signal over a first wire to a DRAM. The DRAM receives a first signal having a balanced number of logical zero-to-one transitions and one-to-zero transitions and samples the first signal at a rising edge of the timing signal to produce a respective sampled value. The device further includes a receiver circuit to receive the respective sampled value from the DRAM over a plurality of wires separate from the first wire. In a first mode, the transmitter circuit repeatedly transmits incrementally offset versions of the timing signal to the DRAM until sampled values received from the DRAM change from a logical zero to a logical one or vice versa; and in a second mode, it transmits write data over the plurality of wires to the DRAM according to a write timing offset generated based on the sampled values.
137 Citations
21 Claims
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1. A memory controller to control a memory device, the memory controller comprising:
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a transmitter to output a calibration sequence to the memory device; a receiver to receive a signal representing a phase difference between a clock signal received at the memory device and the calibration sequence as received by the memory device; and
,circuitry to apply a transmit timing offset to write data, based on the phase difference between the clock signal as received at the memory device and the calibration sequence as received by the memory device. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A memory controller to control a memory device, the memory controller comprising:
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a first output to transmit, in response to a calibration mode, a calibration sequence to the memory device; circuitry to place the memory device in a mode to receive the calibration sequence; and
,a first input to receive, from the memory device, phase data representing a phase difference between a clock signal as received by the memory device and the calibration sequence as received by the memory device. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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15. A method of operating a memory controller, comprising:
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sending, from the memory controller, a calibration sequence; receiving, by the memory controller, a signal generated by the memory device that represents a phase difference between the calibration sequence, as received by the memory device, and a clock signal; and
,adjusting, by the memory controller, a timing offset for write operations based on the phase difference between the calibration sequence, as received by the memory device, and the clock signal. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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Specification