Frequency Divider
AssigneeCavium, Inc.
InventorsJingDong Deng, Omer O. Yildirim
Life of this patent
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Abstract
A frequency divider circuit comprises a first divider chain including at least one first divider cell and a second divider chain coupled to the first divider chain to form an extendable divider chain. The second divider chain includes at least one second divider cell with a respective reset control. An effective length of the extendable divider chain may be altered, dynamically, via the respective reset control. Altering the effective length, dynamically, enables a division ratio of the frequency divider circuit to be changed, dynamically. The frequency divider circuit may be advantageously employed by applications that rely upon a dynamic division ratio, such as a fractional-N (frac-N) phase-locked loop (PLL).
Claims19
A frequency divider circuit, the frequency divider circuit comprising:
- a first divider circuit including at least one first divider cell;
- a second divider circuit coupled to the first divider circuit to form an extendable divider chain, the second divider circuit including at least one second divider cell with a respective reset control, an effective length of the extendable divider chain altered, dynamically, via the respective reset control, wherein the effective length is a total number of divider cells in the extendable divider chain that influence a division ratio of the frequency divider circuit and
- an output frequency generator circuit including a logic gate, the output frequency generator circuit coupled to the first divider circuit, the logic gate configured to generate a divided output frequency signal employed to update the respective reset control.
A method for performing frequency division by a frequency divider circuit, the method comprising:
- coupling a first divider circuit including at least one first divider cell to a second divider circuit to form an extendable divider chain, the second divider circuit including at least one second divider cell with a respective reset control;
- altering an effective length of the extendable divider chain, dynamically, via the respective reset control, enabling the frequency divider circuit to alter, dynamically, the frequency division performed, wherein the effective length is a total number of divider cells in the extendable divider chain that influence a division ratio of the frequency divider circuit;
- and
- coupling an output frequency generator circuit including a logic gate to the first divider circuit, performing a logical function by the logic gate to generate a divided output frequency signal, and employing the divided output frequency signal to update the respective reset control.
Dependencies are inferred from the claim text.