Serial data link with automatic power down
AssigneeTexas Instruments Incorporated
InventorsAndrea Bonelli, Francois Bauduin
Life of this patent
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Abstract
A serial data link (10) includes a transmitter (12) using a differential transmitter cell (20) to transmit data using differential signals and a receiver (14) using a differential receiver cell (22) to receive differential signals. When the transmitter (12) is in a power-down state, the differential signals from the differential transmitter cell (20) are set to an illegal state that is detected by the receiver cell (22). Upon detecting the illegal state, unnecessary circuitry in the receiver (14) is shut off or placed in a low power state to conserve energy. When data transmission resumes, the receiver cell (22) automatically restores power to its circuitry and resumes receiving data.
Claims18
A serial data link comprising:
- a differential transmitter for transmitting data using differential signals and for transmitting a predetermined output not used for data transmission when the differential transmitter is in a power-down state;
- and
- a differential receiver coupled to the differential transmitter for receiving data using differential signals and for detecting the predetermined output from the differential transmitter in order to disable selected circuitry while data is not being transmitted by said differential transmitter.
A method of communication data over a serial data link, comprising the steps of:
- transmitting data from a transmitter using differential signals;
- transmitting a predetermined output not used for data transmission from the transmitter when the transmitter is in a power-down state;
- receiving data in a receiver from differential signals;
- detecting the predetermined output from the differential transmitter;
- and
- disabling circuitry in the receiver responsive to detecting said predetermined output.
A mobile communication device including first and second circuits with a communication path therebetween, comprising:
- a differential transmitter in said first circuit for transmitting data using differential signals on said communication path and for transmitting a predetermined output not used for data transmission on said communication path when the differential transmitter is in a power-down state;
- and
- a differential receiver in said second circuit coupled to the differential transmitter via said communication path for receiving data using differential signals and for detecting the predetermined output from the differential transmitter in order to disable selected circuitry in said second circuit while data is not being transmitted by said differential transmitter.
Dependencies are inferred from the claim text.