Method and apparatus for clock data recovery from manchester coded serial data stream
AssigneeRockwell Automation Technologies, Inc.
InventorsDarshini H. Mehta, Alan Campbell
Life of this patent
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Abstract
Methods and apparatus are presented for obtaining clock data from Manchester coded serial data streams, in which received data is sampled at a sample rate higher than the serial data baud rate, multi-bit groups of transition bits are generated which individually indicate data transition locations in a corresponding multi-bit sampled data bit group, and clock data is derived using the multi-bit groups of transition bits without requiring receipt of synchronization data or receipt of a separate clock.
Claims17
A method for deriving clock data from a Manchester coded serial data stream, the method comprising:
- receiving a Manchester coded serial data stream corresponding to an input baud rate;
- sampling the Manchester coded serial data stream at a sample rate higher than the input baud rate to obtain multi-bit groups of sampled bits;
- constructing multi-bit groups of transition bits, the multi-bit groups of transition bits individually indicating data transition locations in a corresponding multi-bit group of sampled bits;
- and
- deriving clock data based solely on the multi-bit groups of transition bits.
A computer readable medium with computer executable instructions for deriving clock data from a Manchester coded serial data stream, the computer readable medium comprising computer executable instructions for:
- receiving a Manchester coded serial data stream corresponding to an input baud rate;
- sampling the Manchester coded serial data stream at a sample rate higher than the input baud rate to obtain multi-bit groups of sampled bits;
- constructing multi-bit groups of transition bits, the multi-bit groups of transition bits individually indicating data transition locations in a corresponding multi-bit group of sampled bits;
- and
- deriving clock data based solely on the multi-bit groups of transition bits.
A receiver for processing a Manchester coded serial data stream, the receiver comprising:
- a sampling circuit operative to sample the Manchester coded serial data stream at a sample rate higher than the input baud rate to obtain multi-bit groups of sampled bits;
- a transition circuit operative to generate multi-bit groups of transition bits, the individual groups of transition bits indicating data transition locations in a corresponding multi-bit group of sampled bits;
- and
- a clock data recovery circuit operative to generate clock data based solely on the multi-bit groups of transition bits.
A motor drive, comprising:
- power conversion circuitry operative to receive input power from a power source and to provide output power to drive a motor load;
- and
- a receiver for processing a Manchester coded serial data stream received by the motor drive, the receiver comprising:
- a sampling circuit operative to sample the Manchester coded serial data stream at a sample rate higher than the input baud rate to obtain multi-bit groups of sampled bits;
- a transition circuit operative to generate multi-bit groups of transition bits, the individual groups of transition bits indicating data transition locations in a corresponding multi-bit group of sampled bits;
- and
- a clock data recovery circuit operative to generate clock data based solely on the multi-bit groups of transition bits.
Dependencies are inferred from the claim text.