System for providing a calibrated clock and methods thereof
AssigneeFreescale Semiconductor, Inc.
InventorsJohn Pigott, Thomas Jeffrey Reiter
Life of this patent
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Abstract
A system and methods are provided for calibrating timing in a remote device to timing in a source device. The source device dictates timing signals to be generated in the remote device. A calibration routine is processed to calibrate timing in the remote device to timing in the source device. The source device provides a reference signal that dictates a period of time to the remote device. The remote device tracks a number of local clock cycles generated for the duration of the dictated period of time. The remote device then establishes a time base for translating a number of clock cycles dictated by the source device to a number of clock cycles generated within the remote device.
Claims40
A method comprising:
- receiving a standard signal at an input of a first device, wherein the standard signal is associated with a first mode of operation;
- receiving, during a second mode of operation different from the first mode of operation, at the input of the first device, a first time reference signal from a second device;
- and
- correlating a timing event of the first time reference signal to an internal clock of the first device to determine a time base relative to a duration of time used to receive the first time reference signal.
A system comprising:
- a source device having:
- a source clock to generate a source clock signal;
- an output node to provide a first time reference to an input port of a first remote device;
- the first remote device having:
- an input node coupled to the output node of said source device to receive a standard signal in a first mode of operation and said first time reference in a second mode of operation;
- a counter to identify a number of clock cycles generated by an internal clock for a duration specified through said first time reference, during said second mode of operation;
- a control signal generator to determine a time base based on said number of clock cycles;
- an output node to provide to a target device a control signal based on said time base;
- said internal clock;
- and
- said target device having an input node coupled to the output node of said first remote device, said input node receiving said control signal and said target device performing a function based on said control signal.
A system comprising:
- a serial communications interface having:
- a serial data node to receive serial commands, wherein said serial data node is used to receive a command to initiate a second mode of operation;
- a serial clock node to receive a signal to clock in bits at the serial data node;
- an enable node to receive a first enable signal to enable serial communications;
- a signal node to receive a standard signal in a first mode of operation and a time reference signal in the second mode of operation, wherein a completion of the time reference signal is used to initiate the first mode of operation;
- a counter to track a number of clock cycles generated by a local clock, said counter having:
- a reset node to initialize a count of the number of clock cycles;
- an enable node to receive a second enable signal to enable a counting of the clock cycles;
- an output node to provide a count of the number of clock cycles;
- a control signal generator to generate a control signal based on the count of the number of clock cycles, said control signal generator having an input node coupled to the output node of the counter to receive said count of the number of clock cycles;
- and
- said local clock to generate said clock cycles.
A method comprising:
- receiving a first signal of a first operational type at an input of a first device, wherein the first signal is associated with a first mode of operation;
- receiving at the input, during a second mode of operation, a second signal of a second operational type, wherein the first operational type is different than the second operational type;
- and
- correlating a timing event received as part of the second signal to an internal clock of the first device to determine a time base relative to the first time reference signal.
Dependencies are inferred from the claim text.