Data on clock lane of source synchronous links
AssigneeSTMicroelectronics International N.V.
InventorsTapas NANDY, Nitin GUPTA
Life of this patent
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Abstract
A source synchronous data transmission system includes a data transmitting device and a data receiving device. A dedicated data line carries a data signal from the data transmission device to the data receiving device. A dedicated clock line carries a modulated clock signal from the data transmission device to the data receiving device. The data transmission device includes a clock data driver configured to encode data into the modulated clock signal by modulating an amplitude of the modulated clock signal. Thus, the clock line of the source synchronous data transmission system carries the clock signal and additional data.
Claims20
A device, comprising:
- a clock signal generator configured to generate a clock signal;
- a data source;
- a clock data driver coupled to the clock signal generator and to the data source, the clock data driver including a modulation circuit configured to generate a modulated clock signal, based on the clock signal, that encodes first data from the data source into the modulated clock signal by modulating an absolute value of an amplitude of the clock signal based on a value of the first data, the clock data driver modulates the amplitude of the clock signal between a first threshold value and a second threshold value, the first and second threshold values representing respective data values of the first data;
- and
- a clock output coupled to the clock data driver, the clock output configured to output the modulated clock signal to a receiving device.
A method comprising:
- generating a first clock signal in a data transmitting device;
- generating, by a modulation circuit in the data transmitting device, a modulated clock signal that encodes first data in the modulated clock signal by modulating an absolute value of an amplitude of the clock signal based on a value of the first data, the amplitude of the clock signal being modulated between a first threshold value and a second threshold value, the first and second threshold values representing respective data values of the first data;
- outputting the modulated clock signal from a clock output of the data transmitting device;
- and
- outputting a data signal from a data output of the transmitting device, the data signal including second data.
A system comprising:
- a data transfer device including:
- a clock signal generator configured to generate a clock signal;
- a data source;
- a clock data driver coupled to the clock signal generator and to the data source, the clock data driver including a modulation circuit configured to generate a modulated clock signal, based on the clock signal, that encodes first data from the data source into the modulated clock signal by modulating an absolute value of an amplitude of the clock signal based on a value of the first data, the clock data driver modulates the amplitude of the clock signal between a first threshold value and a second threshold value, the first and second threshold values representing respective data values of the first data;
- a clock output coupled to the clock data driver, the clock output configured to output the modulated clock signal to a receiving device;
- and
- a data output configured to output a data signal;
- a data receiving device comprising:
- a clock input coupled to the clock output of the data transfer device and configured to receive the modulated clock signal from the clock output;
- and
- a data input coupled to the data output of the data transfer device and configured to receive the data signal from the data output of the data transfer device, the data receiving device configured to retrieve first data from the modulated clock signal and second data from the data signal.
Dependencies are inferred from the claim text.