Precision timing generation
First Claim
1. A precision timing generator, comprising:
- a reference clock signal;
a clock generator generating from the reference clock signal a plurality of clock signals of equal frequency, each clock signal being offset from another one of the clock by a predetermined phase;
a first selector circuit selecting a first group of two clock signals, the selected clock signals being offset from each other by the predetermined phase;
a first interpolator circuit receiving the first group of selected clock signals and associating with each clock signal a predetermined weight, and providing a first resulting clock signal that is offset from each of the selected clock signal by less than the predetermined phase and in proportional to the predetermined weights;
a second selector circuit selecting a second group of two clock signals, the selected clock signals being offset from each other by the predetermined phase;
a second interpolator circuit receiving the second group of selected clock signals and associating with each clock signal a predetermined weight, and providing a second resulting clock signal that is offset from each of the selected clock signal by less than the predetermined phase and in proportional to the predetermined weights; and
a logic gate applying a logic operation on the first resulting clock signal and the second resulting clock signal to provide a precision clock signal.
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Accused Products
Abstract
A precision timing generator and an associate method provide a precise clock signal based on a reference clock signal. Using the reference clock signal in a phase locked loop or delay locked loop, a number of clock signals of equal frequency are generated separated consecutively by a known phase. Two of these clock signals of consecutive phases are selected for interpolation for higher precision according to predetermined weights. The resulting interpolated clock signal has a phase offset that is intermediate between the selected clock signals in proportion to the predetermined weights. In one implementation, a second interpolated clock signal is created by selecting and weighting a second group of clock signals using independent selection and weights. The two interpolated clock signals are then combined by logic operations to provide a precise clock signal of predetermined duty cycle and phase.
25 Citations
14 Claims
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1. A precision timing generator, comprising:
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a reference clock signal; a clock generator generating from the reference clock signal a plurality of clock signals of equal frequency, each clock signal being offset from another one of the clock by a predetermined phase; a first selector circuit selecting a first group of two clock signals, the selected clock signals being offset from each other by the predetermined phase; a first interpolator circuit receiving the first group of selected clock signals and associating with each clock signal a predetermined weight, and providing a first resulting clock signal that is offset from each of the selected clock signal by less than the predetermined phase and in proportional to the predetermined weights; a second selector circuit selecting a second group of two clock signals, the selected clock signals being offset from each other by the predetermined phase; a second interpolator circuit receiving the second group of selected clock signals and associating with each clock signal a predetermined weight, and providing a second resulting clock signal that is offset from each of the selected clock signal by less than the predetermined phase and in proportional to the predetermined weights; and a logic gate applying a logic operation on the first resulting clock signal and the second resulting clock signal to provide a precision clock signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for precision timing generation, comprising:
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providing a reference clock signal;
generating from the reference clock signal a plurality of clock signals of equal frequency, each clock signal being offset from another one of the clock by a predetermined phase;selecting a first group of two clock signals, the selected clock signals being offset from each other by the predetermined phase; associating with each clock signal a predetermined weight and interpolating the selected clock signals to provide a first resulting clock signal that is offset from each of the selected clock signal by less than the predetermined phase and in proportional to the predetermined weights; selecting a second group of two clock signals, the selected clock signals being offset from each other by the predetermined phase; associating with each clock signal of the second group of selected clock signals a predetermined weight, and interpolating the second group of selected clock signals to provide a second resulting clock signal that is offset from each of the selected clock signal by less than the predetermined phase and in proportional to the predetermined weights; and applying a logic operation on the first resulting clock signal and the second resulting clock signal to provide a precision clock signal. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification